Patchwork Re: EHCI support in QEMU

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Submitter David S. Ahern
Date March 3, 2010, 10:44 p.m.
Message ID <4B8EE632.7090303@cisco.com>
Download mbox | patch
Permalink /patch/46878/
State New
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Comments

David S. Ahern - March 3, 2010, 10:44 p.m.
On 03/03/2010 04:21 AM, Niels de Vos wrote:
> On Tue, Mar 2, 2010 at 10:48 AM, Kevin Wolf <kwolf@redhat.com> wrote:
>> Am 01.03.2010 22:17, schrieb Jan Kiszka:
>>> Niels de Vos wrote:
>>>> If someone is interested in this partially ported patch, I'm happy to
>>>> share, but it will at least need some attention to make it compile.
>>>> After that, lots of tests need to be done and probably quite some
>>>> bugfixes are required. I'm happy to assist, but do not have a lot of
>>>> time to spare on this hobby project. On the occasion that it is something
>>>> more solid and starting to do something, I will of course inform this list
>>>> again.
>>>
>>> OK, to keep this heavy ball rolling, I would suggest posting your patch.
>>> Either it's already in a good shape to get it merged as experimental
>>> feature. Or I will pick it up in git tree, collect patches as they fly
>>> in, and will keep on pushing it upstream. I can't promise spending much
>>> time on hacking, but integration work, basic testing, and some more or
>>> less helpful comments should be feasible.
>>
>> Yes, please post it. I won't promise anything either, but maybe I can
>> find some time to help a bit. Anyway, I'd love to see EHCI in qemu.
> 
> Okay, here it is. Please note that the patch is very raw, does not
> compile and even basic things like indention is broken at the moment.
> Please refer to
> http://lists.gnu.org/archive/html/qemu-devel/2008-10/msg01326.html for
> the original author, nothing seriously of this patch is done by me.
> 
> Kind regards and thanks for your help,
> Niels

FWIW: the attached compiles and qemu does not die (patch created against
qemu-kvm.git but applies to qemu.git as well). For now I disabled uhci
so that the device is attached to the ehci bus. I can attach a usb key,
but lsusb in the guest (fedora core 12) does not show it.

David
Jan Kiszka - March 3, 2010, 11:47 p.m.
David S. Ahern wrote:
> On 03/03/2010 04:21 AM, Niels de Vos wrote:
>> On Tue, Mar 2, 2010 at 10:48 AM, Kevin Wolf <kwolf@redhat.com> wrote:
>>> Am 01.03.2010 22:17, schrieb Jan Kiszka:
>>>> Niels de Vos wrote:
>>>>> If someone is interested in this partially ported patch, I'm happy to
>>>>> share, but it will at least need some attention to make it compile.
>>>>> After that, lots of tests need to be done and probably quite some
>>>>> bugfixes are required. I'm happy to assist, but do not have a lot of
>>>>> time to spare on this hobby project. On the occasion that it is something
>>>>> more solid and starting to do something, I will of course inform this list
>>>>> again.
>>>> OK, to keep this heavy ball rolling, I would suggest posting your patch.
>>>> Either it's already in a good shape to get it merged as experimental
>>>> feature. Or I will pick it up in git tree, collect patches as they fly
>>>> in, and will keep on pushing it upstream. I can't promise spending much
>>>> time on hacking, but integration work, basic testing, and some more or
>>>> less helpful comments should be feasible.
>>> Yes, please post it. I won't promise anything either, but maybe I can
>>> find some time to help a bit. Anyway, I'd love to see EHCI in qemu.
>> Okay, here it is. Please note that the patch is very raw, does not
>> compile and even basic things like indention is broken at the moment.
>> Please refer to
>> http://lists.gnu.org/archive/html/qemu-devel/2008-10/msg01326.html for
>> the original author, nothing seriously of this patch is done by me.
>>
>> Kind regards and thanks for your help,
>> Niels
> 
> FWIW: the attached compiles and qemu does not die (patch created against
> qemu-kvm.git but applies to qemu.git as well). For now I disabled uhci
> so that the device is attached to the ehci bus. I can attach a usb key,
> but lsusb in the guest (fedora core 12) does not show it.
> 

Thanks for your work, David and Niels! I assume that David based this on
Niels' patch, so there is nothing to be merged? David's version built
for me, so I pushed

	git://git.kiszka.org/qemu.git ehci

So far it's supposed to be a reference for anyone interested in this
topic, willing to test or even to hack on it. I will collect and merge
improvements as they are sent to the list.

Jan
David S. Ahern - March 3, 2010, 11:58 p.m.
On 03/03/2010 04:47 PM, Jan Kiszka wrote:
> 
> Thanks for your work, David and Niels! I assume that David based this on
> Niels' patch, so there is nothing to be merged? David's version built
> for me, so I pushed
> 
> 	git://git.kiszka.org/qemu.git ehci
> 
> So far it's supposed to be a reference for anyone interested in this
> topic, willing to test or even to hack on it. I will collect and merge
> improvements as they are sent to the list.
> 
> Jan
> 

Yes, I took Niels post as a start. Addressed a few white space issues,
made some of the initializations parallel the uhci code and removed the
mem_base from the read/write functions (causing segfaults due to
outbounds referencing -- addr > MMIO_SIZE -- and do not appear to be
needed).

David
Niels de Vos - March 4, 2010, 3:24 p.m.
On Wed, Mar 3, 2010 at 11:58 PM, David S. Ahern <daahern@cisco.com> wrote:
> On 03/03/2010 04:47 PM, Jan Kiszka wrote:
>>
>> Thanks for your work, David and Niels! I assume that David based this on
>> Niels' patch, so there is nothing to be merged? David's version built
>> for me, so I pushed
>>
>>       git://git.kiszka.org/qemu.git ehci
>>
>> So far it's supposed to be a reference for anyone interested in this
>> topic, willing to test or even to hack on it. I will collect and merge
>> improvements as they are sent to the list.
>>
>> Jan
>>
>
> Yes, I took Niels post as a start. Addressed a few white space issues,
> made some of the initializations parallel the uhci code and removed the
> mem_base from the read/write functions (causing segfaults due to
> outbounds referencing -- addr > MMIO_SIZE -- and do not appear to be
> needed).


Hi David and Jan,

thanks, sounds really cool! I don't have any knowledge about the qemu
internals, therefore the details would be too difficult for me anyway
:)

I'll keep an eye on the progress, and maybe I'll be able to test and
contribute a it more later on.

Cheers,
Niels

Patch

diff --git a/Makefile.target b/Makefile.target
index 82caf20..6932515 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -223,7 +223,7 @@  obj-i386-y += pckbd.o $(sound-obj-y) dma.o
 obj-i386-y += vga.o vga-pci.o vga-isa.o
 obj-i386-y += fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
 obj-i386-y += cirrus_vga.o apic.o ioapic.o parallel.o acpi.o piix_pci.o
-obj-i386-y += usb-uhci.o vmmouse.o vmport.o vmware_vga.o hpet.o
+obj-i386-y += usb-uhci.o usb-ehci.o vmmouse.o vmport.o vmware_vga.o hpet.o
 obj-i386-y += device-hotplug.o pci-hotplug.o smbios.o wdt_ib700.o
 obj-i386-y += extboot.o
 obj-i386-y += ne2000-isa.o debugcon.o multiboot.o
diff --git a/hw/pc.c b/hw/pc.c
index 0aebae9..8f5c0dc 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -28,6 +28,7 @@ 
 #include "vmware_vga.h"
 #include "usb-uhci.h"
 #include "usb-ohci.h"
+#include "usb-ehci.h"
 #include "prep_pci.h"
 #include "apb_pci.h"
 #include "block.h"
@@ -1039,8 +1044,14 @@  static void pc_init1(ram_addr_t ram_size,
 
     cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device, hd);
 
+    //  TODO the piix3 does not have EHCI - looks like ICH4
+	//  was first southbridge to support it.
     if (pci_enabled && usb_enabled) {
-        usb_uhci_piix3_init(pci_bus, piix3_devfn + 2);
+#if 0
+        usb_uhci_piix3_init(pci_bus, piix3_devfn + 3);
+#else
+        usb_ehci_init(pci_bus, piix3_devfn + 2);
+#endif
     }
 
     if (pci_enabled && acpi_enabled) {
diff --git a/hw/pci_ids.h b/hw/pci_ids.h
index fe7a121..a1bdf50 100644
--- a/hw/pci_ids.h
+++ b/hw/pci_ids.h
@@ -89,6 +89,7 @@ 
 #define PCI_VENDOR_ID_INTEL              0x8086
 #define PCI_DEVICE_ID_INTEL_82441        0x1237
 #define PCI_DEVICE_ID_INTEL_82801AA_5    0x2415
+#define PCI_DEVICE_ID_INTEL_82801D       0x24CD
 #define PCI_DEVICE_ID_INTEL_ESB_9        0x25ab
 #define PCI_DEVICE_ID_INTEL_82371SB_0    0x7000
 #define PCI_DEVICE_ID_INTEL_82371SB_1    0x7010
diff --git a/hw/usb-ehci.c b/hw/usb-ehci.c
new file mode 100644
index 0000000..aa8ed9e
--- /dev/null
+++ b/hw/usb-ehci.c
@@ -0,0 +1,2081 @@ 
+/*
+ * QEMU USB EHCI Emulation
+ *
+ * Copyright(c) 2008  Emutex Ltd. (address@hidden)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or(at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * TODO:
+ *  o Downstream port handoff
+ */
+
+#include "hw.h"
+#include "qemu-timer.h"
+#include "usb.h"
+#include "pci.h"
+#include "usb-ehci.h"
+#include "monitor.h"
+
+#define EHCI_DEBUG 1
+#if EHCI_DEBUG
+//#define DEBUG(x) timed_printf x 
+#define DEBUG(x) printf x
+#else
+#define DEBUG(x)
+#endif
+//static int timed_printf(const char *fmt, ...);
+
+// #define TDEBUG
+// #define DEBUG_PACKET
+
+#define ASSERT(x) { if (!(x)) { printf("Assertion failed in usb-echi.c line %d\n", __LINE__); exit(1); } }
+
+#define MMIO_SIZE        0x1000
+
+#define CAPREGBASE       0x0000        // Capability Registers Base Address
+
+#define CAPLENGTH        CAPREGBASE + 0x0000
+#define HCIVERSION       CAPREGBASE + 0x0002
+#define HCSPARAMS        CAPREGBASE + 0x0004
+#define HCCPARAMS        CAPREGBASE + 0x0008
+#define EECP             HCCPARAMS + 1
+#define HCSPPORTROUTE1   CAPREGBASE + 0x000c
+#define HCSPPORTROUTE2   CAPREGBASE + 0x0010
+
+#define OPREGBASE        0x0020        // Operational Registers Base Address
+
+#define USBCMD           OPREGBASE + 0x0000
+#define USBCMD_RUNSTOP   (1 << 0)      // run / Stop
+#define USBCMD_HCRESET   (1 << 1)      // HC Reset
+#define USBCMD_FLS       (3 << 2)      // Frame List Size
+#define USBCMD_FLS_SH    2             // Frame List Size Shift
+#define USBCMD_PSE       (1 << 4)      // Periodic Schedule Enable
+#define USBCMD_ASE       (1 << 5)      // Asynch Schedule Enable
+#define USBCMD_IAAD      (1 << 6)      // Int Asynch Advance Doorbell
+#define USBCMD_LHCR      (1 << 7)      // Light Host Controller Reset
+#define USBCMD_ASPMC     (3 << 8)      // Async Sched Park Mode Count
+#define USBCMD_ASPME     (1 << 11)     // Async Sched Park Mode Enable
+#define USBCMD_ITC       (0x7f << 16)  // Int Threshold Control
+#define USBCMD_ITC_SH    16            // Int Threshold Control Shift
+
+#define USBSTS           OPREGBASE + 0x0004
+#define USBSTS_RO_MASK   0x0000003f
+#define USBSTS_INT       (1 << 0)      // USB Interrupt
+#define USBSTS_ERRINT    (1 << 1)      // Error Interrupt
+#define USBSTS_PCD       (1 << 2)      // Port Change Detect
+#define USBSTS_FLR       (1 << 3)      // Frame List Rollover
+#define USBSTS_HSE       (1 << 4)      // Host System Error
+#define USBSTS_IAA       (1 << 5)      // Interrupt Async Advance
+#define USBSTS_HALT      (1 << 12)     // HC Halted
+#define USBSTS_REC       (1 << 13)     // Reclamation
+#define USBSTS_PSS       (1 << 14)     // Periodic Schedule Status
+#define USBSTS_ASS       (1 << 15)     // Asynchronous Schedule Status
+
+/*
+ *  Interrupt enable bits correspond to the interrupt active bits in USBSTS
+ *  so no need to redefine here.
+ */
+#define USBINTR              OPREGBASE + 0x0008
+#define USBINTR_MASK         0x0000003f
+
+#define FRINDEX              OPREGBASE + 0x000c
+#define CTRLDSSEGMENT        OPREGBASE + 0x0010
+#define PERIODICLISTBASE     OPREGBASE + 0x0014
+#define ASYNCLISTADDR        OPREGBASE + 0x0018
+#define ASYNCLISTADDR_MASK   0xffffffe0
+
+#define CONFIGFLAG           OPREGBASE + 0x0040
+
+#define PORTSC               (OPREGBASE + 0x0044)
+#define PORTSC_BEGIN         PORTSC
+#define PORTSC_END           (PORTSC + 4 * NB_PORTS)
+/*
+ * Bits that are reserverd or are read-only are masked out of values
+ * written to us by software
+ */
+#define PORTSC_RO_MASK       0x007021c5
+#define PORTSC_RWC_MASK      0x0000002a
+#define PORTSC_WKOC_E        (1 << 22)    // Wake on Over Current Enable
+#define PORTSC_WKDS_E        (1 << 21)    // Wake on Disconnect Enable
+#define PORTSC_WKCN_E        (1 << 20)    // Wake on Connect Enable
+#define PORTSC_PTC           (15 << 16)   // Port Test Control
+#define PORTSC_PTC_SH        16           // Port Test Control shift
+#define PORTSC_PIC           (3 << 14)    // Port Indicator Control
+#define PORTSC_PIC_SH        14           // Port Indicator Control Shift
+#define PORTSC_POWNER        (1 << 13)    // Port Owner
+#define PORTSC_PPOWER        (1 << 12)    // Port Power
+#define PORTSC_LINESTAT      (3 << 10)    // Port Line Status
+#define PORTSC_LINESTAT_SH   10           // Port Line Status Shift
+#define PORTSC_PRESET        (1 << 8)     // Port Reset
+#define PORTSC_SUSPEND       (1 << 7)     // Port Suspend
+#define PORTSC_FPRES         (1 << 6)     // Force Port Resume
+#define PORTSC_OCC           (1 << 5)     // Over Current Change
+#define PORTSC_OCA           (1 << 4)     // Over Current Active
+#define PORTSC_PEDC          (1 << 3)     // Port Enable/Disable Change
+#define PORTSC_PED           (1 << 2)     // Port Enable/Disable
+#define PORTSC_CSC           (1 << 1)     // Connect Status Change
+#define PORTSC_CONNECT       (1 << 0)     // Current Connect Status
+
+//#define EHCI_NOMICROFRAMES
+
+#ifdef EHCI_NOMICROFRAMES
+#define FRAME_TIMER_FREQ 2000
+#else
+#define FRAME_TIMER_FREQ 8000
+#endif
+
+#define NB_MAXINTRATE    8        // Max rate at which controller issues ints
+#define NB_PORTS         4        // Number of downstream ports
+#define BUFF_SIZE        20480    // Max bytes to transfer per transaction
+#define MAX_ITERATIONS   1000     // Max number of states before we abort
+#define MAX_QH           1000     // Max allowable queue heads in a chain
+
+/*  Internal periodic / asynchronous schedule state machine states
+ */
+typedef enum {
+    EST_INACTIVE = 1000,
+    EST_ACTIVE,
+    EST_EXECUTING,
+    EST_SLEEPING,
+    /*  The following states are internal to the state machine function
+    */
+    EST_WAITLISTHEAD,
+    EST_DORELOAD,
+    EST_WAITSTARTEVENT,
+    EST_FETCHENTRY,
+    EST_FETCHQH,
+    EST_FETCHITD,
+    EST_ADVANCEQUEUE,
+    EST_FETCHQTD,
+    EST_EXECUTE,
+    EST_WRITEBACK,
+    EST_HORIZONTALQH
+} EHCI_STATES;
+
+/*  EHCI spec version 1.0 Section 3.3
+ */
+typedef struct EHCIitd {
+    uint32_t next;
+#define NLPTR_GET(x)             ((x) & 0xffffffe0)
+#define NLPTR_TYPE_GET(x)        (((x) >> 1) & 3)
+#define NLPTR_TYPE_ITD           0
+#define NLPTR_TYPE_QH            1
+#define NLPTR_TYPE_STITD         2
+#define NLPTR_TYPE_FSTN          3
+#define NLPTR_TBIT(x)            ((x) & 1)
+
+    uint32_t transact[8];
+#define ITD_XACT_ACTIVE          (1 << 31)
+#define ITD_XACT_DBERROR         (1 << 30)
+#define ITD_XACT_BABBLE          (1 << 29)
+#define ITD_XACT_XACTERR         (1 << 28)
+#define ITD_XACT_LENGTH_MASK     0x0fff0000
+#define ITD_XACT_LENGTH_SH       16
+#define ITD_XACT_IOC             (1 << 15)
+#define ITD_XACT_PGSEL_MASK      0x00007000
+#define ITD_XACT_PGSEL_SH        12
+#define ITD_XACT_OFFSET_MASK     0x00000fff
+
+    uint32_t bufptr[7];
+#define ITD_BUFPTR_MASK          0xfffff000
+#define ITD_BUFPTR_SH            12
+#define ITD_BUFPTR_EP_MASK       0x00000f00
+#define ITD_BUFPTR_EP_SH         8
+#define ITD_BUFPTR_DEVADDR_MASK  0x0000007f
+#define ITD_BUFPTR_DIRECTION     (1 << 11)
+#define ITD_BUFPTR_MAXPKT_MASK   0x000007ff
+#define ITD_BUFPTR_MULT_MASK     0x00000003
+} EHCIitd;
+
+/*  EHCI spec version 1.0 Section 3.4
+ */
+typedef struct EHCIsitd {
+    uint32_t next;                  // Standard next link pointer
+    uint32_t epchar;
+#define SITD_EPCHAR_IO              (1 << 31)
+#define SITD_EPCHAR_PORTNUM_MASK    0x7f000000
+#define SITD_EPCHAR_PORTNUM_SH      24
+#define SITD_EPCHAR_HUBADD_MASK     0x007f0000
+#define SITD_EPCHAR_HUBADDR_SH      16
+#define SITD_EPCHAR_EPNUM_MASK      0x00000f00
+#define SITD_EPCHAR_EPNUM_SH        8
+#define SITD_EPCHAR_DEVADDR_MASK    0x0000007f
+
+    uint32_t uframe;
+#define SITD_UFRAME_CMASK_MASK      0x0000ff00
+#define SITD_UFRAME_CMASK_SH        8
+#define SITD_UFRAME_SMASK_MASK      0x000000ff
+
+    uint32_t results;
+#define SITD_RESULTS_IOC              (1 << 31)
+#define SITD_RESULTS_PGSEL            (1 << 30)
+#define SITD_RESULTS_TBYTES_MASK      0x03ff0000
+#define SITD_RESULTS_TYBYTES_SH       16
+#define SITD_RESULTS_CPROGMASK_MASK   0x0000ff00
+#define SITD_RESULTS_CPROGMASK_SH     8
+#define SITD_RESULTS_ACTIVE           (1 << 7)
+#define SITD_RESULTS_ERR              (1 << 6)
+#define SITD_RESULTS_DBERR            (1 << 5)
+#define SITD_RESULTS_BABBLE           (1 << 4)
+#define SITD_RESULTS_XACTERR          (1 << 3)
+#define SITD_RESULTS_MISSEDUF         (1 << 2)
+#define SITD_RESULTS_SPLITXSTATE      (1 << 1)
+
+    uint32_t bufptr[2];
+#define BUFPTR_MASK                   0xfffff000
+#define BUFPTR_CURROFF_MASK           0x00000fff
+#define BUFPTR_TPOS_MASK              0x00000018
+#define BUFPTR_TPOS_SH                3
+#define BUFPTR_TCNT_MASK              0x00000007
+
+    uint32_t backptr;                 // Standard next link pointer
+} EHCIsitd;
+
+/*  EHCI spec version 1.0 Section 3.5
+ */
+typedef struct EHCIqtd {
+    uint32_t next;                    // Standard next link pointer
+    uint32_t altnext;                 // Standard next link pointer
+    uint32_t token;
+#define QTD_TOKEN_DTOGGLE             (1 << 31)
+#define QTD_TOKEN_TBYTES_MASK         0x7fff0000
+#define QTD_TOKEN_TBYTES_SH           16
+#define QTD_TOKEN_IOC                 (1 << 15)
+#define QTD_TOKEN_CPAGE_MASK          0x00007000
+#define QTD_TOKEN_CPAGE_SH            12
+#define QTD_TOKEN_CERR_MASK           0x00000c00
+#define QTD_TOKEN_CERR_SH             10
+#define QTD_TOKEN_PID_MASK            0x00000300
+#define QTD_TOKEN_PID_SH              8
+#define QTD_TOKEN_ACTIVE              (1 << 7)
+#define QTD_TOKEN_HALT                (1 << 6)
+#define QTD_TOKEN_DBERR               (1 << 5)
+#define QTD_TOKEN_BABBLE              (1 << 4)
+#define QTD_TOKEN_XACTERR             (1 << 3)
+#define QTD_TOKEN_MISSEDUF            (1 << 2)
+#define QTD_TOKEN_SPLITXSTATE         (1 << 1)
+#define QTD_TOKEN_PING                (1 << 0)
+
+    uint32_t bufptr[5];               // Standard buffer pointer
+} EHCIqtd;
+
+/*  EHCI spec version 1.0 Section 3.6
+ */
+typedef struct EHCIqh {
+    uint32_t next;                    // Standard next link pointer
+
+    uint32_t epchar;
+#define QH_EPCHAR_RL_MASK             0xf0000000
+#define QH_EPCHAR_RL_SH               28
+#define QH_EPCHAR_C                   (1 << 27)
+#define QH_EPCHAR_MPLEN_MASK          0x07FF0000
+#define QH_EPCHAR_MPLEN_SH            16
+#define QH_EPCHAR_H                   (1 << 15)
+#define QH_EPCHAR_DTC                 (1 << 14)
+#define QH_EPCHAR_EPS_MASK            0x00003000
+#define QH_EPCHAR_EPS_SH              12
+#define QH_EPCHAR_EP_MASK             0x00000f00
+#define QH_EPCHAR_EP_SH               8
+#define QH_EPCHAR_I                   (1 << 7)
+#define QH_EPCHAR_DEVADDR_MASK        0x0000007f
+
+    uint32_t epcap;
+#define QH_EPCAP_MULT_MASK            0xc0000000
+#define QH_EPCAP_MULT_SH              30
+#define QH_EPCAP_PORTNUM_MASK         0x3f800000
+#define QH_EPCAP_PORTNUM_SH           23
+#define QH_EPCAP_HUBADDR_MASK         0x007f0000
+#define QH_EPCAP_HUBADDR_SH           16
+#define QH_EPCAP_CMASK_MASK           0x0000ff00
+#define QH_EPCAP_CMASK_SH             8
+#define QH_EPCAP_SMASK_MASK           0x000000ff
+
+    uint32_t current;                 // Standard next link pointer
+    uint32_t qtdnext;                 // Standard next link pointer
+    uint32_t altnext;
+#define QH_ALTNEXT_NAKCNT_MASK        0x0000001e
+#define QH_ALTNEXT_NAKCNT_SH          1
+
+    uint32_t token;                   // Same as QTD token
+    uint32_t bufptr[5];               // Standard buffer pointer
+#define BUFPTR_CPROGMASK_MASK         0x000000ff
+#define BUFPTR_FRAMETAG_MASK          0x0000001f
+#define BUFPTR_SBYTES_MASK            0x00000fe0
+#define BUFPTR_SBYTES_SH              5
+} EHCIqh;
+
+/*  EHCI spec version 1.0 Section 3.7
+ */
+typedef struct EHCIfstn {
+    uint32_t next;                    // Standard next link pointer
+    uint32_t backptr;                 // Standard next link pointer
+} EHCIfstn;
+
+typedef struct {
+    PCIDevice dev;
+    qemu_irq irq;
+    target_phys_addr_t mem_base;
+    int mem;
+    int num_ports;
+    /*
+     *  EHCI spec version 1.0 Section 2.3
+     *  Host Controller Operational Registers
+     */
+    union {
+        uint8_t mmio[MMIO_SIZE];
+        struct {
+            uint8_t cap[OPREGBASE];
+            uint32_t usbcmd;
+            uint32_t usbsts;
+            uint32_t usbintr;
+            uint32_t frindex;
+            uint32_t ctrldssegment;
+            uint32_t periodiclistbase;
+            uint32_t asynclistaddr;
+            uint32_t notused[9];
+            uint32_t configflag;
+            uint32_t portsc[NB_PORTS];
+        };
+    };
+    /*
+     *  Internal states, shadow registers, etc
+     */
+    uint32_t sofv;
+    QEMUTimer *frame_timer;
+    int attach_poll_counter;
+    int astate;                        // Current state in asynchronous schedule
+    int pstate;                        // Current state in periodic schedule
+    USBPort ports[NB_PORTS];
+    unsigned char buffer[BUFF_SIZE];
+    EHCIqh qh;
+    EHCIqtd qtd;
+    USBBus bus;
+    USBPacket usb_packet;
+    int async_port_in_progress;
+    int async_complete;
+    uint32_t qhaddr;
+    uint32_t itdaddr;
+    uint32_t qtdaddr;
+    uint32_t tbytes;
+    int pid;
+    int exec_status;
+    int isoch_pause;
+    uint32_t last_run_usec;
+    uint32_t frame_end_usec;
+} EHCIState;
+
+static inline uint32_t get_field(uint32_t data, uint32_t mask, int shift)
+{
+    return((data & mask) >> shift);
+}
+
+static inline void set_field(uint32_t *data, uint32_t val,
+                              uint32_t mask, int shift)
+{
+    *data &= ~mask;
+    *data |=(val << shift);
+}
+
+static void dump_ptr(const char *s, uint32_t ptr, int has_type)
+{
+    int t = NLPTR_TYPE_GET(ptr);
+
+    printf("%s%08X", s, NLPTR_GET(ptr));
+
+    if (has_type) {
+        printf("(PTR type is %s)",
+            t == NLPTR_TYPE_ITD ? "ITD" :
+           (t == NLPTR_TYPE_QH ? "QH" :
+           (t == NLPTR_TYPE_STITD ? "STITD" :
+           (t == NLPTR_TYPE_FSTN ? "FSTN" : "****"))));
+    }
+
+    printf("%s\n", NLPTR_TBIT(ptr) ? " TBIT set" : "");
+}
+
+static void dump_qtd(EHCIqtd *qtd, uint32_t qtdaddr)
+{
+    int pid;
+
+    pid =(qtd->token & QTD_TOKEN_PID_MASK) >> QTD_TOKEN_PID_SH;
+
+    printf("    QTD analysis      %08X\n"
+            "    === ========      ========\n", qtdaddr);
+
+    printf("    NakCnt:           %d\n",
+             (qtd->altnext & QH_ALTNEXT_NAKCNT_MASK) >> QH_ALTNEXT_NAKCNT_SH);
+    dump_ptr("    Next:             ", qtd->next, 0);
+    dump_ptr("    Alternate:        ", qtd->altnext, 0);
+    printf("    Data Toggle:      %s        ",
+              qtd->token & QTD_TOKEN_DTOGGLE ? "Yes " : "No  ");
+    printf("    Total Bytes:      %d\n",
+             (qtd->token & QTD_TOKEN_TBYTES_MASK) >> QTD_TOKEN_TBYTES_SH);
+    printf("    IOC:              %s        ",
+              qtd->token & QTD_TOKEN_IOC ? "Yes " : "No  ");
+    printf("    C_Page:           %d\n",
+             (qtd->token & QTD_TOKEN_CPAGE_MASK) >> QTD_TOKEN_CPAGE_SH);
+    printf("    CErr:             %-4d        ",
+             (qtd->token & QTD_TOKEN_CERR_MASK) >> QTD_TOKEN_CERR_SH);
+    printf("    PID code:         %s\n",
+              pid == 0 ? "OUT" :
+             (pid == 1 ? "IN" :
+             (pid == 2 ? "SETUP" : "****")));
+    printf("    Flags:            %s%s%s%s%s%s%s%s\n",
+              qtd->token & QTD_TOKEN_ACTIVE ? "ACTIVE " : "",
+              qtd->token & QTD_TOKEN_HALT ? "HALT " : "",
+              qtd->token & QTD_TOKEN_DBERR ? "DBERR " : "",
+              qtd->token & QTD_TOKEN_BABBLE ? "BABBLE " : "",
+              qtd->token & QTD_TOKEN_XACTERR ? "XACTERR " : "",
+              qtd->token & QTD_TOKEN_MISSEDUF ? "MISSEDUF " : "",
+              qtd->token & QTD_TOKEN_SPLITXSTATE ? "SPLITXSTATE " : "",
+              qtd->token & QTD_TOKEN_PING ? "PING " : "");
+    printf("    Current Offset    %d\n",
+              qtd->bufptr[0] & BUFPTR_CURROFF_MASK);
+    printf("    === ========      ========\n");
+}
+
+static void dump_qh(EHCIqh *qh, uint32_t qhaddr)
+{
+    int speed =(qh->epchar & QH_EPCHAR_EPS_MASK) >> QH_EPCHAR_EPS_SH;
+
+    printf("QH analysis       %08X\n"
+            "== ========       ========\n", qhaddr);
+
+    dump_ptr("Horizontal:       ", qh->next, 1);
+    printf("Nak Count Reload: %d\n",
+           (qh->epchar & QH_EPCHAR_RL_MASK) >> QH_EPCHAR_RL_SH);
+    printf("Max Pkt Len:      %d\n",
+           (qh->epchar & QH_EPCHAR_MPLEN_MASK) >> QH_EPCHAR_MPLEN_SH);
+    printf("Control Endpoint: %s        ",
+           (qh->epchar & QH_EPCHAR_C) ? "Yes " : "No  ");
+    printf("H-bit:            %s\n",
+           (qh->epchar & QH_EPCHAR_H) ? "Yes " : "No  ");
+    printf("DTC:              %s        ",
+           (qh->epchar & QH_EPCHAR_DTC) ? "Yes " : "No  ");
+    printf("EndPoint Speed:   %s\n",
+            speed == 0 ? "Full" :
+           (speed == 1 ? "Low " :
+           (speed == 2 ? "High" : "****")));
+    printf("EndPoint:         %-4d        ",
+           (qh->epchar & QH_EPCHAR_EP_MASK) >> QH_EPCHAR_EP_SH);
+    printf("Inactive on next: %s\n",
+           (qh->epchar & QH_EPCHAR_I) ? "Yes" : "No");
+    printf("DevAddr:          %-4d        ",
+             qh->epchar & QH_EPCHAR_DEVADDR_MASK);
+    printf("Mult:             %-4d\n",
+           (qh->epcap & QH_EPCAP_MULT_MASK) >> QH_EPCAP_MULT_SH);
+    printf("PortNum:          %-4d        ",
+           (qh->epcap & QH_EPCAP_PORTNUM_MASK) >> QH_EPCAP_PORTNUM_SH);
+    printf("HubAddr:          %d\n",
+           (qh->epcap & QH_EPCAP_HUBADDR_MASK) >> QH_EPCAP_HUBADDR_SH);
+    printf("C-mask:           %-4d        ",
+           (qh->epcap & QH_EPCAP_CMASK_MASK) >> QH_EPCAP_CMASK_SH);
+    printf("S-mask:           %d\n",
+              qh->epcap & QH_EPCAP_SMASK_MASK);
+    dump_ptr("Current:          ", qh->current, 0);
+
+    dump_qtd((EHCIqtd *)&qh->qtdnext, qhaddr + 16);
+
+    printf("C-prog mask:      %d\n",
+              qh->bufptr[1] & BUFPTR_CPROGMASK_MASK);
+    printf("S-bytes:          %d\n",
+              qh->bufptr[2] & BUFPTR_FRAMETAG_MASK);
+    printf("FrameTag:         %d\n",
+             (qh->bufptr[2] & BUFPTR_SBYTES_MASK) >> BUFPTR_SBYTES_SH);
+    printf("== ========       ========\n");
+}
+
+#ifdef DEBUG_PACKET
+
+static void dump_itd(EHCIitd *itd, uint32_t addr)
+{
+    int i;
+
+    printf("ITD analysis       %08X\n"
+            "=== ========       ========\n", addr);
+
+    dump_ptr("Horizontal:       ", itd->next, 1);
+
+    for(i = 0; i < 8; i++) {
+        printf("Trans Desc %d, len %5d, off %03X, page sel %d, ioc:%s ",
+                  i,
+                  get_field(itd->transact[i], ITD_XACT_LENGTH_MASK,
+                             ITD_XACT_LENGTH_SH),
+                  get_field(itd->transact[i], ITD_XACT_OFFSET_MASK, 0),
+                  get_field(itd->transact[i], ITD_XACT_PGSEL_MASK,
+                             ITD_XACT_PGSEL_SH),
+                  itd->transact[i] & ITD_XACT_IOC ? "Yes" : "No ");
+
+        if (itd->transact[i] & ITD_XACT_ACTIVE)
+            printf("ACTIVE ");
+
+        if (itd->transact[i] & ITD_XACT_DBERROR)
+            printf("DATAERR ");
+
+        if (itd->transact[i] & ITD_XACT_BABBLE)
+            printf("BABBLE ");
+
+        if (itd->transact[i] & ITD_XACT_XACTERR)
+            printf("XACTERR ");
+
+        printf("\n");
+    }
+
+    printf("Device:     %d\n",
+            get_field(itd->bufptr[0], ITD_BUFPTR_DEVADDR_MASK, 0));
+
+    printf("Endpoint:   %d\n",
+            get_field(itd->bufptr[0], ITD_BUFPTR_EP_MASK, ITD_BUFPTR_EP_SH));
+
+    printf("Direction:  %s\n",
+            itd->bufptr[1] & ITD_BUFPTR_DIRECTION ? "IN" : "OUT");
+
+    printf("Max Packet: %d\n",
+            get_field(itd->bufptr[1], ITD_BUFPTR_MAXPKT_MASK, 0));
+
+    printf("Mult:       %d\n",
+            get_field(itd->bufptr[2], ITD_BUFPTR_MULT_MASK, 0));
+
+    for(i = 0; i < 7; i++)
+        printf("Buf Ptr %d: %05X\n", i, itd->bufptr[i] >> 12);
+}
+
+#endif
+
+#if 0
+static int timed_printf(const char *fmt, ...)
+{
+    int msec, usec;
+    static int usec_last;
+    va_list ap;
+
+    usec = qemu_get_clock(vm_clock) / 1000;
+
+    msec = usec - usec_last;
+    usec_last = usec;
+    usec = msec;
+
+    msec /= 1000;
+    msec %= 1000;
+
+    usec %= 1000;
+
+    va_start(ap, fmt);
+    printf("%03d.%03d ", msec, usec);
+    vprintf(fmt, ap);
+    va_end(ap);
+
+    return 0;
+}
+#endif
+
+static inline void ehci_set_interrupt(EHCIState *ehci, int intr)
+{
+    int level = 0;
+
+    // TODO honour interrupt threshold requests
+
+    ehci->usbsts |= intr;
+
+    if ((ehci->usbsts & USBINTR_MASK) & ehci->usbintr)
+        level = 1;
+
+#ifdef TDEBUG
+    DEBUG(("ehci: setting interrupt level %d(st/en)=(%02X/%02X)\n", level,
+            ehci->usbsts & USBINTR_MASK, ehci->usbintr));
+#endif
+    qemu_set_irq(ehci->irq, level);
+}
+
+/* Attach or detach a device on root hub */
+
+static void ehci_attach(USBPort *port, USBDevice *dev)
+{
+    EHCIState *s = port->opaque;
+    uint32_t *portsc = &s->portsc[port->index];
+
+    DEBUG(("ehci_attach invoked for index %d, desc %s\n",
+           port->index, dev ? dev->product_desc : "undefined"));
+
+    if (dev) {
+        if (port->dev) {
+            usb_attach(port, NULL);
+        }
+
+        *portsc |= PORTSC_CONNECT;
+
+        usb_send_msg(dev, USB_MSG_ATTACH);
+        port->dev = dev;
+    } else {
+        *portsc &= ~PORTSC_CONNECT;
+
+        if (port->dev) {
+            dev = port->dev;
+            usb_send_msg(dev, USB_MSG_DETACH);
+        }
+
+        port->dev = NULL;
+    }
+
+    *portsc |= PORTSC_CSC;
+
+    /*
+     *  If a high speed device is attached then we own this port(indicated
+     *  by zero in the PORTSC_POWNER bit field) so set the status bit
+     *  and set an interrupt if enabled.
+     */
+    if ( !(*portsc & PORTSC_POWNER)) {
+        ehci_set_interrupt(s, USBSTS_PCD);
+    }
+}
+
+static void ehci_reset(void *opaque)
+{
+    EHCIState *s = opaque;
+    uint8_t *pci_conf;
+    int i;
+
+    DEBUG(("ehci_reset\n"));
+    pci_conf = s->dev.config;
+
+    memset(&s->mmio[OPREGBASE], 0x00, MMIO_SIZE - OPREGBASE);
+
+    s->usbcmd = NB_MAXINTRATE << USBCMD_ITC_SH;
+    s->usbsts = USBSTS_HALT;
+
+    s->astate = EST_INACTIVE;
+    s->pstate = EST_INACTIVE;
+    s->async_port_in_progress = -1;
+    s->async_complete = 0;
+    s->isoch_pause = -1;
+    s->attach_poll_counter = 0;
+
+    for(i = 0; i < NB_PORTS; i++) {
+        s->portsc[i] = PORTSC_POWNER | PORTSC_PPOWER;
+
+        if (s->ports[i].dev)
+            ehci_attach(&s->ports[i], s->ports[i].dev);
+    }
+}
+
+static uint32_t ehci_mem_readb(void *ptr, target_phys_addr_t addr)
+{
+    EHCIState *s = ptr;
+    uint32_t val;
+
+    val = s->mmio[addr];
+    DEBUG(("mem_readb : addr=0x%08X, val=%02X\n",(int)addr,(int)val));
+
+    return val;
+}
+
+static uint32_t ehci_mem_readw(void *ptr, target_phys_addr_t addr)
+{
+    EHCIState *s = ptr;
+    uint32_t val;
+
+    val = s->mmio[addr] |(s->mmio[addr+1] << 8);
+    DEBUG(("mem_readw : addr=0x%08X, val=0x%04X\n",(int)addr,(int)val));
+
+    return val;
+}
+
+static uint32_t ehci_mem_readl(void *ptr, target_phys_addr_t addr)
+{
+    EHCIState *s = ptr;
+    uint32_t val;
+
+    val = s->mmio[addr] |(s->mmio[addr+1] << 8) |
+          (s->mmio[addr+2] << 16) |(s->mmio[addr+3] << 24);
+
+    DEBUG(("ehci_mem_readl : addr=0x%08X, val=0x%08X\n",(unsigned) addr, val));
+
+    return val;
+}
+
+static void ehci_mem_writeb(void *ptr, target_phys_addr_t addr, uint32_t val)
+{
+    printf("EHCI doesn't handle byte writes to MMIO\n");
+    exit(1);
+}
+
+static void ehci_mem_writew(void *ptr, target_phys_addr_t addr, uint32_t val)
+{
+    printf("EHCI doesn't handle 16-bit writes to MMIO\n");
+    exit(1);
+}
+
+static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
+{
+    uint32_t *portsc = &s->portsc[port];
+    int rwc;
+    USBDevice *dev = s->ports[port].dev;
+
+    DEBUG(("PORTSC  %08X->%08X  rwc=%08X  rw=%08X\n", *portsc, val,
+          (val & PORTSC_RWC_MASK),
+           val & PORTSC_RO_MASK));
+
+    rwc = val & PORTSC_RWC_MASK;
+    val &= PORTSC_RO_MASK;
+
+    // handle_read_write_clear(&val, portsc, PORTSC_PEDC | PORTSC_CSC);
+
+    *portsc &= ~rwc;
+
+    DEBUG(("PORTSC  ->  %08X\n", *portsc));
+
+    if ((val & PORTSC_PRESET) && !(*portsc & PORTSC_PRESET)) {
+        DEBUG(("USBTRAN Port %d reset begin\n", port));
+    }
+
+    if (!(val & PORTSC_PRESET) &&(*portsc & PORTSC_PRESET)) {
+        DEBUG(("USBTRAN Port %d reset done\n", port));
+        ehci_attach(&s->ports[port], dev);
+
+        // TODO how to handle reset of ports with no device
+        if (dev)
+            usb_send_msg(dev, USB_MSG_RESET);
+
+        if (s->ports[port].dev) {
+            DEBUG(("Device was connected before reset, clearing CSC bit\n"));
+            *portsc &= ~PORTSC_CSC;
+        }
+
+        /*  Table 2.16 Set the enable bit(and enable bit change) to indicate
+         *  to SW that this port has a high speed device attached
+         *
+         *  TODO - when to disable?
+         */
+        val |= PORTSC_PED;
+        val |= PORTSC_PEDC;
+    }
+
+    *portsc &= ~PORTSC_RO_MASK;
+    *portsc |= val;
+    DEBUG(("Port status set to 0x%08x\n", *portsc));
+}
+
+static void ehci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
+{
+    EHCIState *s = ptr;
+    int i;
+
+    /* Only aligned reads are allowed on OHCI */
+    if (addr & 3) {
+        printf("usb-ehci: Mis-aligned write\n");
+        return;
+    }
+
+    if (addr >= PORTSC && addr < PORTSC + 4 * NB_PORTS) {
+        DEBUG(("ehci_mem_writel : PORTSC%d->0x%08X \n",
+               (int)(addr-PORTSC)/4, val));
+        handle_port_status_write(s, (addr-PORTSC)/4, val);
+        return;
+    }
+
+    /* Do any register specific pre-write processing here.  */
+
+    switch(addr)
+    {
+    case USBCMD:
+        if ((val & USBCMD_RUNSTOP) && !(s->usbcmd & USBCMD_RUNSTOP)) {
+            DEBUG(("ehci_mem_writel : USBCMD run, clear halt\n"));
+            // printf("Call mod_timer for %p\n", s->frame_timer);
+            qemu_mod_timer(s->frame_timer, qemu_get_clock(vm_clock));
+            s->last_run_usec = qemu_get_clock(vm_clock) / 1000;
+            s->usbsts &= ~USBSTS_HALT;
+        }
+
+        if (!(val & USBCMD_RUNSTOP) &&(s->usbcmd & USBCMD_RUNSTOP)) {
+            DEBUG(("ehci_mem_writel : USBCMD  ** STOP **\n"));
+            // printf("Call del_timer for %p\n", s->frame_timer);
+#if 0
+            qemu_del_timer(s->frame_timer);
+#endif
+            // TODO - should finish out some stuff before setting halt
+            s->usbsts |= USBSTS_HALT;
+        }
+
+        if (val & USBCMD_HCRESET) {
+            DEBUG(("ehci_mem_writel : USBCMD resetting ...\n"));
+            ehci_reset(s);
+            DEBUG(("ehci_mem_writel: USBCMD reset done, clear reset request bit\n"));
+            val &= ~USBCMD_HCRESET;
+        }
+
+        break;
+
+    case USBSTS:
+        val &= USBSTS_RO_MASK;              // bits 6 thru 31 are RO
+        DEBUG(("ehci_mem_writel : USBSTS RWC set to 0x%08X\n", val));
+
+        val =(s->usbsts &= ~val);         // bits 0 thru 5 are R/WC
+        DEBUG(("ehci_mem_writel : USBSTS updating interrupt condition\n"));
+        ehci_set_interrupt(s, 0);
+
+        break;
+
+    case USBINTR:
+        val &= USBINTR_MASK;
+        // DEBUG(("ehci_mem_writel : USBINTR set to 0x%08X\n", val));
+        break;
+
+    case FRINDEX:
+        s->sofv = val >> 3;
+        break;
+
+    case CONFIGFLAG:
+        val &= 0x1;
+
+        if (val) {
+            for(i = 0; i < NB_PORTS; i++)
+                s->portsc[i] &= ~PORTSC_POWNER;
+        }
+
+        break;
+    }
+
+    if (addr != 0x28) {
+        DEBUG(("ehci_mem_writel : addr=0x%08X, val=0x%08X\n",(unsigned) addr, val));
+    }
+
+    *(uint32_t *)(&s->mmio[addr]) = val;
+}
+
+
+// TODO : Put in common header file, duplication from usb-ohci.c
+
+/* Get an array of dwords from main memory */
+static inline int get_dwords(uint32_t addr, uint32_t *buf, int num)
+{
+    int i;
+
+    for(i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
+        cpu_physical_memory_rw(addr,(uint8_t *)buf, sizeof(*buf), 0);
+        *buf = le32_to_cpu(*buf);
+    }
+
+    return 1;
+}
+
+/* Put an array of dwords in to main memory */
+static inline int put_dwords(uint32_t addr, uint32_t *buf, int num)
+{
+    int i;
+
+    for(i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
+        uint32_t tmp = cpu_to_le32(*buf);
+        cpu_physical_memory_rw(addr,(uint8_t *)&tmp, sizeof(tmp), 1);
+    }
+
+    return 1;
+}
+
+// 4.10.2
+
+static void ehci_qh_do_overlay(EHCIState *ehci, EHCIqh *qh, EHCIqtd *qtd)
+{
+    int i;
+    int dtoggle;
+    int ping;
+
+    // remember values in fields to preserve in qh after overlay
+
+    dtoggle = qh->token & QTD_TOKEN_DTOGGLE;
+    ping = qh->token & QTD_TOKEN_PING;
+
+    DEBUG(("setting qh.current from %08X to 0x%08X\n", qh->current,
+            ehci->qtdaddr));
+    qh->current  = ehci->qtdaddr;
+    qh->qtdnext  = qtd->next;
+    qh->altnext  = qtd->altnext;
+    qh->token    = qtd->token;
+
+    if (qh->current < 0x1000) {
+#ifdef DEBUG_PACKET
+        dump_qh(qh, qh->current);
+#endif
+        ASSERT(1==2);
+    }
+
+    if (((qh->epchar & QH_EPCHAR_EPS_MASK) >> QH_EPCHAR_EPS_SH) == 2) {
+        qh->token &= ~QTD_TOKEN_PING;
+        qh->token |= ping;
+    }
+
+    for (i = 0; i < 5; i++)
+        qh->bufptr[i] = qtd->bufptr[i];
+
+    if (!(qh->epchar & QH_EPCHAR_DTC)) {
+        // preserve QH DT bit
+        qh->token &= ~QTD_TOKEN_DTOGGLE;
+        qh->token |= dtoggle;
+    }
+
+    qh->bufptr[1] &= ~BUFPTR_CPROGMASK_MASK;
+    qh->bufptr[2] &= ~BUFPTR_FRAMETAG_MASK;
+
+    // TODO NakCnt
+}
+
+static void ehci_buffer_rw(EHCIState *ehci, EHCIqh *qh, int bytes, int rw)
+{
+    int bufpos = 0;
+    int cpage;
+    uint32_t head;
+    uint32_t tail;
+
+    cpage = get_field(qh->token, QTD_TOKEN_CPAGE_MASK, QTD_TOKEN_CPAGE_SH);
+    ASSERT(cpage == 0);
+
+    DEBUG(("exec: %sing %d bytes to/from %08x\n",
+           rw ? "writ" : "read", bytes, qh->bufptr[0]));
+
+    if (!bytes)
+        return;
+
+    do {
+        head = qh->bufptr[cpage];
+        tail =(qh->bufptr[cpage] & 0xfffff000) + 0x1000;
+
+        if (bytes <=(tail - head))
+            tail = head + bytes;
+
+        DEBUG(("DATA %s cpage:%d head:%08X tail:%08X target:%08X\n",
+                rw ? "WRITE" : "READ ", cpage, head, tail, bufpos));
+
+        ASSERT(bufpos + tail - head <= BUFF_SIZE);
+        ASSERT(tail - head > 0);
+
+        cpu_physical_memory_rw(qh->bufptr[cpage], &ehci->buffer[bufpos],
+                                tail - head, rw);
+
+        bufpos +=(tail - head);
+        bytes -=(tail - head);
+
+        qh->bufptr[cpage] +=(tail - head);
+
+        if (bytes > 0)
+            cpage++;
+    } while (bytes > 0);
+
+    set_field(&qh->token, cpage, QTD_TOKEN_CPAGE_MASK, QTD_TOKEN_CPAGE_SH);
+}
+
+static void ehci_async_complete_packet(USBPacket *packet, void *opaque)
+{
+    EHCIState *ehci = opaque;
+#ifdef DEBUG_PACKET
+    dprintf("Async packet complete\n");
+#endif
+    ehci->async_complete = 1;
+    ehci->exec_status = packet->len;
+}
+
+static int ehci_execute_complete(EHCIState *ehci,
+                                  EHCIqh *qh,
+                                  int ret)
+{
+    if (ret == USB_RET_ASYNC && !ehci->async_complete) {
+        DEBUG(("not done yet\n"));
+        return ret;
+    }
+
+    ehci->async_complete = 0;
+    ehci->async_port_in_progress = -1;
+
+    if (ret < 0) {
+        switch(ret) {
+        case USB_RET_NODEV:
+            printf("USB no device\n");
+            break;
+        case USB_RET_STALL:
+            printf("USB stall\n");
+            qh->token |= QTD_TOKEN_HALT;
+            break;
+        case USB_RET_NAK:
+            DEBUG(("USBTRAN RSP NAK, returning without clear active\n"));
+            return USB_RET_NAK;
+            break;
+        case USB_RET_BABBLE:
+            printf("USB babble TODO\n");
+            ASSERT(ret >= 0);
+            break;
+        default:
+            printf("USB invalid response %d to handle\n",
+                    ret);
+            ASSERT(ret >= 0);
+            break;
+        }
+    } else {
+        // if (ret < maxpkt)
+        // {
+        //     DEBUG(("Short packet condition\n"));
+        //     // TODO check 4.12 for splits
+         // }
+
+        if (ehci->tbytes && ehci->pid == USB_TOKEN_IN) {
+            ASSERT(ret > 0);
+            ehci_buffer_rw(ehci, qh, ret, 1);
+#ifdef TDEBUG
+            printf("Data after execution:\n");
+            // dump_data(ehci->buffer, ehci->tbytes < 64 ? ehci->tbytes : 64);
+            // decode_data(ehci->pid, ehci->buffer, ret);
+#endif
+            ehci->tbytes -= ret;
+        } else
+            ehci->tbytes = 0;
+
+        ASSERT(ehci->tbytes >= 0);
+
+        set_field(&qh->token, ehci->tbytes,
+                   QTD_TOKEN_TBYTES_MASK, QTD_TOKEN_TBYTES_SH);
+    }
+
+    qh->token ^= QTD_TOKEN_DTOGGLE;
+    qh->token &= ~QTD_TOKEN_ACTIVE;
+
+    if (qh->token & QTD_TOKEN_IOC) {
+        // TODO should do this after writeback to memory
+        ehci_set_interrupt(ehci, USBSTS_INT);
+    }
+#ifdef DEBUG_PACKET
+    DEBUG(("QH after execute:-\n"));
+    dump_qh(qh, NLPTR_GET(ehci->qhaddr));
+#endif
+
+#ifdef TDEBUG
+    printf("USBTRAN RSP %3d                          return:(%5d) ",
+            transactid,
+            ret);
+
+    if (ehci->pid == USB_TOKEN_IN) {
+        printf("[%02X %02X %02X %02X ...]\n",
+            *ehci->buffer, *(ehci->buffer+1),
+            *(ehci->buffer+2), *(ehci->buffer+3));
+    }
+    else
+        printf("\n");
+#endif
+    return ret;
+}
+
+// 4.10.3
+
+static int ehci_execute(EHCIState *ehci,
+                          uint32_t qhaddr,
+                          EHCIqh *qh)
+{
+    USBPort *port;
+    USBDevice *dev;
+    int smask;
+    int maxpkt;
+    int ret;
+    int i;
+    int endp;
+    int devadr;
+
+    smask = QH_EPCAP_SMASK_MASK & qh->epcap;
+    ehci->tbytes =(qh->token & QTD_TOKEN_TBYTES_MASK) >> QTD_TOKEN_TBYTES_SH;
+    ehci->pid =(qh->token & QTD_TOKEN_PID_MASK) >> QTD_TOKEN_PID_SH;
+    maxpkt = get_field(qh->epchar, QH_EPCHAR_MPLEN_MASK, QH_EPCHAR_MPLEN_SH);
+    endp = get_field(qh->epchar, QH_EPCHAR_EP_MASK, QH_EPCHAR_EP_SH);
+    devadr = get_field(qh->epchar, QH_EPCHAR_DEVADDR_MASK, 0);
+
+    if ( !(qh->token & QTD_TOKEN_ACTIVE)) {
+        printf("Attempting to execute inactive QH\n");
+        exit(1);;
+    }
+
+    if (smask) {
+        DEBUG(("active interrupt transfer frindex %d for dev %d EP %d\n",
+                ehci->frindex, devadr, endp));
+        // TODO are interrupt always IN ?
+        ehci->pid = USB_TOKEN_IN;
+    } else {
+        DEBUG(("Active non-interrupt QH, executing\n"));
+
+        DEBUG(("pid is %2X\n", ehci->pid));
+
+        switch(ehci->pid) {
+        case 0: ehci->pid = USB_TOKEN_OUT; break;
+        case 1: ehci->pid = USB_TOKEN_IN; break;
+        case 2: ehci->pid = USB_TOKEN_SETUP; break;
+        default: printf("bad token\n"); break;
+        }
+    }
+
+    // TODO set reclam
+
+#ifdef DEBUG_PACKET
+    DEBUG(("QH before execute:-\n"));
+    dump_qh(qh, NLPTR_GET(qhaddr));
+#endif
+
+    if (ehci->tbytes && ehci->pid != USB_TOKEN_IN) {
+        ehci_buffer_rw(ehci, qh, ehci->tbytes, 0);
+#ifdef TDEBUG
+        printf("Data before execution:\n");
+        // dump_data(ehci->buffer, ehci->tbytes < 64 ? ehci->tbytes : 64);
+        // decode_data(ehci->pid, ehci->buffer, ehci->tbytes);
+#endif
+    }
+
+#ifdef TDEBUG
+    printf("\nUSBTRAN REQ %3d dev:%d ep:%d pid:%02X %s bytes:(%5d) ",
+            ++transactid,
+            devadr,
+            endp,
+            ehci->pid,
+           (ehci->pid == USB_TOKEN_SETUP ? "(SETUP)" :
+           (ehci->pid == USB_TOKEN_IN ? "(IN)   " :
+           (ehci->pid == USB_TOKEN_OUT ? "(OUT)  " : "(*****)"))),
+            ehci->tbytes);
+
+    if (ehci->pid != USB_TOKEN_IN) {
+        printf("[%02X %02X %02X %02X ...]\n",
+            *ehci->buffer, *(ehci->buffer+1),
+            *(ehci->buffer+2), *(ehci->buffer+3));
+    }
+    else
+        printf("\n");
+#endif
+
+    ret = USB_RET_NODEV;
+
+    for(i = 0; i < NB_PORTS; i++) {
+        port = &ehci->ports[i];
+        dev = port->dev;
+
+        // TODO sometime we will also need to check if we are the port owner
+
+        if (!(ehci->portsc[i] &(PORTSC_CONNECT))) {
+            DEBUG(("Port %d, no exec, not connected(%08X)\n",
+                    i, ehci->portsc[i]));
+            continue;
+        }
+
+        ehci->usb_packet.pid = ehci->pid;
+        ehci->usb_packet.devaddr = devadr;
+        ehci->usb_packet.devep = endp;
+        ehci->usb_packet.data = ehci->buffer;
+        ehci->usb_packet.len = ehci->tbytes;
+        ehci->usb_packet.complete_cb = ehci_async_complete_packet;
+        ehci->usb_packet.complete_opaque = ehci;
+
+        DEBUG(("calling dev->info->handle_packet\n"));
+        ret = dev->info->handle_packet(dev, &ehci->usb_packet);
+
+        if (ret != USB_RET_NODEV)
+            break;
+    }
+
+    DEBUG(("exit loop dev->info->handle_packet\n"));
+
+    if (ret > BUFF_SIZE || ehci->tbytes > BUFF_SIZE) {
+        printf("bogus QH byte count\n");
+        dump_qh(qh, NLPTR_GET(qhaddr));
+        ASSERT(ret <= BUFF_SIZE && ehci->tbytes <= BUFF_SIZE);
+    }
+
+    if (ret == USB_RET_ASYNC) {
+        ehci->async_port_in_progress = i;
+        ehci->async_complete = 0;
+    }
+
+    return ret;
+}
+
+/*  4.7.2
+ */
+
+static void ehci_process_itd(EHCIState *ehci,
+                             EHCIitd *itd)
+{
+    USBPort *port;
+    USBDevice *dev;
+    int ret;
+    int i, j;
+    int ptr;
+    int pid;
+    int pg;
+    int len;
+    int dir;
+    int devadr;
+    int endp;
+    int maxpkt;
+
+    dir =(itd->bufptr[1] & ITD_BUFPTR_DIRECTION);
+    devadr = get_field(itd->bufptr[0],
+                        ITD_BUFPTR_DEVADDR_MASK, 0);
+    endp = get_field(itd->bufptr[0],
+                      ITD_BUFPTR_EP_MASK, ITD_BUFPTR_EP_SH);
+    maxpkt = get_field(itd->bufptr[1], ITD_BUFPTR_MAXPKT_MASK, 0);
+
+#ifdef EHCI_NOMICROFRAMES
+    for(i = 0; i < 8; i++) {
+#else
+    i =(ehci->frindex & 7);
+#endif
+
+    if (itd->transact[i] & ITD_XACT_ACTIVE) {
+        DEBUG(("ISOCHRONOUS active for frame %d, interval %d\n",
+                ehci->frindex >> 3, i));
+
+        pg = get_field(itd->transact[i], ITD_XACT_PGSEL_MASK,
+                        ITD_XACT_PGSEL_SH);
+        ptr =(itd->bufptr[pg] & ITD_BUFPTR_MASK) |
+             (itd->transact[i] & ITD_XACT_OFFSET_MASK);
+        len = get_field(itd->transact[i], ITD_XACT_LENGTH_MASK,
+                         ITD_XACT_LENGTH_SH);
+
+        ASSERT(len <= BUFF_SIZE);
+
+        DEBUG(("ISOCH: buffer %08X len %d\n", ptr, len));
+
+        if (!dir) {
+            cpu_physical_memory_rw(ptr, &ehci->buffer[0], len, 0);
+            pid = USB_TOKEN_OUT;
+        } else
+            pid = USB_TOKEN_IN;
+
+        ret = USB_RET_NODEV;
+
+        for(j = 0; j < NB_PORTS; j++) {
+            port = &ehci->ports[j];
+            dev = port->dev;
+
+            // TODO sometime we will also need to check if we are the port owner
+
+            if (!(ehci->portsc[j] &(PORTSC_CONNECT))) {
+                DEBUG(("Port %d, no exec, not connected(%08X)\n",
+                        j, ehci->portsc[j]));
+                continue;
+            }
+
+            ehci->usb_packet.pid = ehci->pid;
+            ehci->usb_packet.devaddr = devadr;
+            ehci->usb_packet.devep = endp;
+            ehci->usb_packet.data = ehci->buffer;
+            ehci->usb_packet.len = len;
+            ehci->usb_packet.complete_cb = ehci_async_complete_packet;
+            ehci->usb_packet.complete_opaque = ehci;
+
+            DEBUG(("calling dev->info->handle_packet\n"));
+            ret = dev->info->handle_packet(dev, &ehci->usb_packet);
+
+            if (ret != USB_RET_NODEV)
+                break;
+        }
+
+        /*  In isoch, there is no facility to indicate a NAK so let's
+         *  instead just complete a zero-byte transaction.  Setting
+         *  DBERR seems too draconian.
+         */
+
+        if (ret == USB_RET_NAK) {
+            if (ehci->isoch_pause > 0) {
+                DEBUG(("ISOCH: received a NAK but paused so returning\n"));
+                ehci->isoch_pause--;
+                return;
+            } else if (ehci->isoch_pause == -1) {
+                DEBUG(("ISOCH: recv NAK & isoch pause inactive, setting\n"));
+                // Pause frindex for up to 50 msec waiting for data from
+                // remote
+                ehci->isoch_pause = 50;
+                return;
+            } else {
+                DEBUG(("ISOCH: isoch pause timeout! return 0\n"));
+                ret = 0;
+            }
+        } else {
+            DEBUG(("ISOCH: received ACK, clearing pause\n"));
+            ehci->isoch_pause = -1;
+        }
+
+        if (ret >= 0) {
+            itd->transact[i] &= ~ITD_XACT_ACTIVE;
+
+            if (itd->transact[i] & ITD_XACT_IOC) {
+                // TODO should do this after writeback to memory
+                ehci_set_interrupt(ehci, USBSTS_INT);
+            }
+        }
+
+        if (ret >= 0 && dir) {
+            cpu_physical_memory_rw(ptr, &ehci->buffer[0], len, 1);
+
+            if (ret != len) {
+                DEBUG(("ISOCH IN expected %d, got %d\n",
+                        len, ret));
+                set_field(&itd->transact[i],
+                           ret,
+                           ITD_XACT_LENGTH_MASK,
+                           ITD_XACT_LENGTH_SH);
+            }
+        }
+    }
+
+#ifdef EHCI_NOMICROFRAMES
+    }
+#endif
+}
+
+/* This is the state machine that is common to both async and periodic */
+
+static int ehci_advance_state(EHCIState *ehci,
+                                int async,
+                                int state,
+                                uint32_t entry)
+{
+    EHCIqh *qh = &ehci->qh;
+    EHCIqtd *qtd = &ehci->qtd;
+    EHCIitd itd;
+    int again = 0;
+    int loopcount = 0;
+    int transactCtr;
+    int smask;
+    int reload;
+    int nakcnt;
+
+    do {
+        DEBUG(("advance_state: again=%d\n", again));
+        again = 0;
+        // ASSERT(loopcount++ < MAX_ITERATIONS);
+
+        switch(state) {
+        /*  This state is the entry point for asynchronous schedule
+         *  processing.  Entry here consitutes a EHCI start event state(4.8.5)
+         */
+        case EST_WAITLISTHEAD:
+            DEBUG(("WAITLISTHEAD\n"));
+
+            if (async)
+                ehci->usbsts |= USBSTS_REC;
+
+            /*  Find the head of the list
+             */
+
+            for(loopcount = 0; loopcount < MAX_QH; loopcount++) {
+                get_dwords(NLPTR_GET(entry),(uint32_t *) qh,
+                            sizeof(EHCIqh) >> 2);
+
+                if (qh->epchar & QH_EPCHAR_H) {
+                    DEBUG(("QH %08X is the HEAD of the list\n", entry));
+                    break;
+                }
+
+                DEBUG(("QH %08X is NOT the HEAD of the list\n", entry));
+                entry = qh->next;
+            }
+
+            entry |=(NLPTR_TYPE_QH << 1);
+            ASSERT(loopcount < MAX_QH);
+            loopcount = 0;
+
+            state = EST_FETCHENTRY;
+            again = 1;
+            break;
+
+        /*  This state is the entry point for periodic schedule
+         *  processing as well as being a continuation state for async
+         *  processing.
+         */
+        case EST_FETCHENTRY:
+            DEBUG(("FETCHENTRY\n"));
+
+            if (qemu_get_clock(vm_clock) / 1000 > ehci->frame_end_usec) {
+                if (async) {
+                    DEBUG(("FRAME timer elapsed, exit state machine\n"));
+                    state = EST_ACTIVE;
+                    break;
+                } else
+                    DEBUG(("WARNING - frame timer elapsed during periodic\n"));
+            }
+
+            if (NLPTR_TBIT(entry)) {
+                state = EST_ACTIVE;
+                break;
+            }
+
+            if (NLPTR_TYPE_GET(entry) == NLPTR_TYPE_QH) {
+                state = EST_FETCHQH;
+                ehci->qhaddr = entry;
+                again = 1;
+                break;
+            }
+
+            if (NLPTR_TYPE_GET(entry) == NLPTR_TYPE_ITD) {
+                state = EST_FETCHITD;
+                ehci->itdaddr = entry;
+                again = 1;
+                break;
+            }
+
+            // TODO handle types other than QH
+            ASSERT(NLPTR_TYPE_GET(entry) == NLPTR_TYPE_QH);
+            break;
+
+        case EST_FETCHQH:
+            get_dwords(NLPTR_GET(ehci->qhaddr),(uint32_t *) qh, 
+                       sizeof(EHCIqh) >> 2);
+            DEBUG(("FETCHQH: Fetched QH at address %08X "
+                    "(next is %08X, h-bit is %d)\n",
+                    ehci->qhaddr, qh->next, qh->epchar & QH_EPCHAR_H));
+
+#ifdef DEBUG_PACKET
+            dump_qh(qh, NLPTR_GET(ehci->qhaddr));
+#endif
+
+            if (async) {
+                /*  EHCI spec version 1.0 Section 4.8.3
+                 */
+                if (qh->epchar & QH_EPCHAR_H) {
+                    DEBUG(("h-bit set\n"));
+
+                    if (!(ehci->usbsts & USBSTS_REC)) {
+                        DEBUG(("h-bit and !reclam, done\n"));
+                        state = EST_ACTIVE;
+                        break;
+                    }
+                }
+                /*  EHCI spec version 1.0 Section 4.10.1
+                 */
+                if ( !(qh->epcap & QH_EPCAP_SMASK_MASK)) {
+                    DEBUG(("not intr, clear reclam\n"));
+                    ehci->usbsts &= ~USBSTS_REC;
+                }
+            } else {
+                DEBUG(("exec: qh check, frindex is %d,%d\n",
+                         (ehci->frindex >> 3),(ehci->frindex & 7)));
+            }
+
+            reload = get_field(qh->epchar, QH_EPCHAR_RL_MASK, QH_EPCHAR_RL_SH);
+
+            if (reload) {
+                DEBUG(("reloading nakcnt to %d\n",
+                        reload));
+                set_field(&qh->altnext, reload, QH_ALTNEXT_NAKCNT_MASK,
+                           QH_ALTNEXT_NAKCNT_SH);
+            }
+
+            if (qh->token & QTD_TOKEN_ACTIVE) {
+                if ((qh->token & QTD_TOKEN_HALT)) {
+                    printf("Active, Halt, ** ILLEGAL **\n");
+                    state = EST_ACTIVE;
+                } else {
+                    DEBUG(("Active, !Halt, execute - fetchqtd\n"));
+                    ehci->qtdaddr = qh->current;
+                    state = EST_FETCHQTD;
+                    again = 1;
+                }
+            } else {
+                if (qh->token & QTD_TOKEN_HALT) {
+                    DEBUG(("!Active, Halt, go horiz\n"));
+                    state = EST_HORIZONTALQH;
+                    again = 1;
+                } else {
+                    /*  EHCI spec version 1.0 Section 4.10.2
+                     */
+                    DEBUG(("!Active, !Halt, adv q\n"));
+                    state = EST_ADVANCEQUEUE;
+                    again = 1;
+                }
+            }
+
+            break;
+
+        case EST_FETCHITD:
+            get_dwords(NLPTR_GET(ehci->itdaddr),(uint32_t *) &itd,
+                        sizeof(EHCIitd) >> 2);
+            DEBUG(("FETCHITD: Fetched ITD at address %08X "
+                    "(next is %08X)\n",
+                    ehci->itdaddr, itd.next));
+
+#ifdef DEBUG_PACKET
+            dump_itd(&itd, NLPTR_GET(ehci->itdaddr));
+#endif
+
+            ehci_process_itd(ehci, &itd);
+#ifdef DEBUG_PACKET
+            dump_itd(&itd, NLPTR_GET(ehci->itdaddr));
+#endif
+            put_dwords(NLPTR_GET(ehci->itdaddr),(uint32_t *) &itd,
+                        sizeof(EHCIitd) >> 2);
+            entry = itd.next;
+            state = EST_FETCHENTRY;
+            again = 1;
+            break;
+
+        case EST_ADVANCEQUEUE:
+            DEBUG(("ADVANCEQUEUE\n"));
+            if ((qh->token & QTD_TOKEN_TBYTES_MASK) != 0 &&
+                NLPTR_TBIT(qh->altnext) == 0) {
+                ehci->qtdaddr = qh->altnext;
+                DEBUG(("tbytes!=0 and tbit = 0, go with altnext\n"));
+            } else {
+                if (NLPTR_TBIT(qh->qtdnext)) {
+                    state = EST_HORIZONTALQH;
+                    again = 1;
+                    break;
+                }
+
+                ehci->qtdaddr = qh->qtdnext;
+            }
+            state = EST_FETCHQTD;
+            again = 1;
+            break;
+
+        case EST_FETCHQTD:
+            DEBUG(("FETCHQTD: Fetching QTD at address %08X\n", ehci->qtdaddr));
+            get_dwords(NLPTR_GET(ehci->qtdaddr),(uint32_t *) qtd,
+                        sizeof(EHCIqtd) >> 2);
+
+            if (qtd->token & QTD_TOKEN_ACTIVE) {
+                state = EST_EXECUTE;
+                again = 1;
+                break;
+            } else {
+                DEBUG(("abort advance, not active\n"));
+                state = EST_HORIZONTALQH;
+                again = 1;
+                break;
+            }
+
+            break;
+
+        case EST_HORIZONTALQH:
+            entry = qh->next;
+            state = EST_FETCHENTRY;
+            again = 1;
+            break;
+
+        case EST_EXECUTE:
+            if (async) {
+                DEBUG(("\n\n>>>>> ASYNC STATE MACHINE execute\n"));
+            } else {
+                DEBUG(("\n\n>>>>> PERIODIC STATE MACHINE execute\n"));
+            }
+
+#ifdef DEBUG_PACKET
+            dump_qh(qh, NLPTR_GET(ehci->qhaddr));
+            dump_qtd(qtd, NLPTR_GET(ehci->qtdaddr));
+#endif
+
+            smask = QH_EPCAP_SMASK_MASK & qh->epcap;
+
+#ifndef EHCI_NOMICROFRAMES
+            if (smask &&(smask &(1 <<(ehci->frindex & 7))) == 0) {
+                DEBUG(("PERIODIC active not interval: "
+                        "mask is %d, "
+                        "frindex is %d,%d\n",
+                        smask,
+                        (ehci->frindex >> 3),(ehci->frindex & 7)));
+
+                state = EST_HORIZONTALQH;
+                again = 1;
+                break;
+            }
+#endif
+
+            if (smask) {
+                DEBUG(("PERIODIC active !!! "
+                        "mask is %d, "
+                        "frindex is %d,%d\n",
+                        smask,
+                        (ehci->frindex >> 3),(ehci->frindex & 7)));
+            }
+
+            reload = get_field(qh->epchar, QH_EPCHAR_RL_MASK, QH_EPCHAR_RL_SH);
+            nakcnt = get_field(qh->altnext, QH_ALTNEXT_NAKCNT_MASK, 
+                               QH_ALTNEXT_NAKCNT_SH);
+            if (reload && !nakcnt) {
+                DEBUG(("RL != 0 but NakCnt == 0, no execute\n"));
+                state = EST_HORIZONTALQH;
+                again = 1;
+                break;
+            }
+
+            transactCtr = get_field(qh->epcap,
+                                     QH_EPCAP_MULT_MASK, QH_EPCAP_MULT_SH);
+
+            // TODO verify enough time remains in the uframe as in 4.4.1.1
+
+            // TODO write back ptr to async list when done or out of time
+
+            // TODO Windows does not seem to ever set the MULT field
+
+#if 0
+            if (!transactCtr &&(qh->epcap & QH_EPCAP_SMASK_MASK) > 0)
+            {
+                DEBUG(("ZERO transactctr for int qh, go HORIZ\n"));
+                *state = EST_HORIZONTALQH;
+                again = 1;
+                break;
+            }
+#endif
+
+            if (!transactCtr) {
+                transactCtr = 1; // TODO - check at what level do we repeat
+
+                if (qh->epcap & QH_EPCAP_SMASK_MASK)
+                    DEBUG(("WARN - ZERO transactctr force to 1 for intr\n"));
+            }
+
+            DEBUG(("exec: ctr is %d\n", transactCtr));
+            DEBUG(("exec: frindex is %d,%d\n",
+                   (ehci->frindex >> 3),(ehci->frindex & 7)));
+
+            ehci_qh_do_overlay(ehci, qh, qtd);
+            ehci->exec_status = ehci_execute(ehci, ehci->qhaddr, qh);
+            state = EST_EXECUTING;
+
+            if (ehci->exec_status != USB_RET_ASYNC)
+                again = 1;
+
+            break;
+
+        case EST_EXECUTING:
+            DEBUG(("Enter EXECUTING\n"));
+            ehci->exec_status = ehci_execute_complete(ehci, qh,
+                                                       ehci->exec_status);
+
+            if (ehci->exec_status == USB_RET_ASYNC)
+                break;
+
+            DEBUG(("finishing exec\n"));
+            transactCtr = get_field(qh->epcap,
+                                     QH_EPCAP_MULT_MASK, QH_EPCAP_MULT_SH);
+
+            if (transactCtr)
+                transactCtr--;
+
+            set_field(&qh->epcap, transactCtr,
+                       QH_EPCAP_MULT_MASK, QH_EPCAP_MULT_SH);
+
+            reload = get_field(qh->epchar, QH_EPCHAR_RL_MASK, QH_EPCHAR_RL_SH);
+            nakcnt = get_field(qh->altnext, QH_ALTNEXT_NAKCNT_MASK,
+                               QH_ALTNEXT_NAKCNT_SH);
+
+            if (reload != 0) {
+                if (ehci->exec_status == USB_RET_NAK) {
+                    nakcnt--;
+
+                    DEBUG(("Nak occured and RL != 0, dec NakCnt to %d\n",
+                            nakcnt));
+                } else {
+                    nakcnt = reload;
+
+                    DEBUG(("Nak didn't occur, reloading to %d\n",
+                            nakcnt));
+                }
+
+                set_field(&qh->altnext, nakcnt, QH_ALTNEXT_NAKCNT_MASK,
+                           QH_ALTNEXT_NAKCNT_SH);
+            }
+
+            /*
+             *  Write the qh back to guest physical memory.  This step isn't
+             *  in the EHCI spec but we need to do it since we don't share
+             *  physical memory with our guest VM.
+             */
+
+            DEBUG(("write QH to VM memory\n"));
+#ifdef DEBUG_PACKET
+            dump_qh(qh, NLPTR_GET(ehci->qhaddr));
+#endif
+            put_dwords(NLPTR_GET(ehci->qhaddr),(uint32_t *) qh,
+                        sizeof(EHCIqh) >> 2);
+
+            // 4.10.5
+
+            if (qh->token & QTD_TOKEN_ACTIVE)
+                state = EST_HORIZONTALQH;
+            else
+                state = EST_WRITEBACK;
+
+            again = 1;
+            break;
+
+        case EST_WRITEBACK:
+            /*  Write back the QTD from the QH area */
+            DEBUG(("write QTD to VM memory\n"));
+            put_dwords(NLPTR_GET(ehci->qtdaddr),(uint32_t *) &qh->qtdnext,
+                        sizeof(EHCIqtd) >> 2);
+            /* TODO confirm next state.  For now, keep going if async
+             * but stop after one qtd if periodic
+             */
+            // if (async)
+            // {
+                state = EST_FETCHQH;
+                again = 1;
+            // }
+            // else
+           //          state = EST_ACTIVE;
+            break;
+
+        default:
+            printf("Bad state!\n");
+            break;
+            }
+    }
+    while (again);
+
+    return state;
+}
+
+static void ehci_advance_async_state(EHCIState *ehci)
+{
+    switch(ehci->astate) {
+    case EST_INACTIVE:
+        if (ehci->usbcmd & USBCMD_ASE) {
+            DEBUG(("ASYNC going active\n"));
+            ehci->usbsts |= USBSTS_ASS;
+            ehci->astate = EST_ACTIVE;
+            // No break, fall through to ACTIVE
+        } else
+            break;
+
+    case EST_ACTIVE:
+        if ( !(ehci->usbcmd & USBCMD_ASE)) {
+            DEBUG(("ASYNC going inactive\n"));
+            ehci->usbsts &= ~USBSTS_ASS;
+            ehci->astate = EST_INACTIVE;
+            break;
+        }
+
+        DEBUG(("\n    ===   ===   ===   ===   ===   ===\n\n"));
+        if (ehci->usbcmd & USBCMD_IAAD) {
+            /*  Async advance doorbell interrupted requested
+             */
+            ehci->usbcmd &= ~USBCMD_IAAD;
+            ehci_set_interrupt(ehci, USBSTS_IAA);
+        }
+
+        ehci->astate = ehci_advance_state(ehci, 1,
+                                           EST_WAITLISTHEAD,
+                                           ehci->asynclistaddr);
+        break;
+
+    case EST_EXECUTING:
+        DEBUG(("async state adv for executing\n"));
+        ehci->astate = ehci_advance_state(ehci, 1,
+                                           EST_EXECUTING, ehci->qhaddr);
+        break;
+
+    default:
+        printf("Bad asynchronous state %d\n",
+                ehci->astate);
+        ASSERT(1==2);
+    }
+}
+
+static void ehci_advance_periodic_state(EHCIState *ehci)
+{
+    uint32_t entry;
+    uint32_t list;
+
+    // 4.6
+
+    switch(ehci->pstate) {
+    case EST_INACTIVE:
+        if ( !(ehci->frindex & 7) &&(ehci->usbcmd & USBCMD_PSE)) {
+            DEBUG(("PERIODIC going active\n"));
+            ehci->usbsts |= USBSTS_PSS;
+            ehci->pstate = EST_ACTIVE;
+            // No break, fall through to ACTIVE
+        } else
+            break;
+
+    case EST_ACTIVE:
+        if ( !(ehci->frindex & 7) && !(ehci->usbcmd & USBCMD_PSE)) {
+            DEBUG(("PERIODIC going inactive\n"));
+            ehci->usbsts &= ~USBSTS_PSS;
+            ehci->pstate = EST_INACTIVE;
+            break;
+        }
+
+        list = ehci->periodiclistbase & 0xfffff000;
+        list |=((ehci->frindex & 0x1ff8) >> 1);
+
+        cpu_physical_memory_rw(list,(uint8_t *) &entry, sizeof entry, 0);
+        entry = le32_to_cpu(entry);
+
+        DEBUG(("periodic state adv fr=%d.  [%08X] -> %08X\n",
+                ehci->frindex / 8, list, entry));
+        ehci->pstate = ehci_advance_state(ehci, 0,
+                                           EST_FETCHENTRY, entry);
+        break;
+
+    case EST_EXECUTING:
+        DEBUG(("periodic state adv for executing\n"));
+        ehci->pstate = ehci_advance_state(ehci, 0,
+                                           EST_EXECUTING, ehci->qhaddr);
+        break;
+
+    default:
+        printf("Bad periodic state %d\n",
+                ehci->pstate);
+        ASSERT(1==2);
+    }
+}
+
+static void ehci_frame_timer(void *opaque)
+{
+    EHCIState *ehci = opaque;
+    int64_t expire_time, t_now;
+    int usec_elapsed;
+    int frames;
+    int usec_now;
+    int i;
+    int skipped_frames = 0;
+
+
+    t_now = qemu_get_clock(vm_clock);
+    expire_time = t_now + (get_ticks_per_sec() / FRAME_TIMER_FREQ);
+    if (expire_time == t_now)
+        expire_time++;
+
+    usec_now = t_now / 1000;
+    usec_elapsed = usec_now - ehci->last_run_usec;
+    ehci->frame_end_usec = usec_now + 1000;
+
+#ifdef EHCI_NOMICROFRAMES
+    frames = usec_elapsed / 1000;
+    ehci->frame_end_usec = usec_now + 1000;
+#else
+    frames = usec_elapsed / 125;
+    ehci->frame_end_usec = usec_now + 125;
+#endif
+
+#ifdef TDEBUG
+    DEBUG(("Frame timer, usec elapsed since last %d, frames %d\n",
+            usec_elapsed, frames));
+#endif
+
+    for(i = 0; i < frames; i++) {
+        if ( !(ehci->usbsts & USBSTS_HALT)) {
+            if (ehci->isoch_pause <= 0) {
+#ifdef EHCI_NOMICROFRAMES
+                ehci->frindex += 8;
+#else
+                ehci->frindex++;
+#endif
+            }
+
+            if (ehci->frindex > 0x00001fff) {
+                ehci->frindex = 0;
+#ifdef TDEBUG
+                DEBUG(("PERIODIC frindex rollover\n"));
+#endif
+                ehci_set_interrupt(ehci, USBSTS_FLR);
+            }
+
+            ehci->sofv =(ehci->frindex - 1) >> 3;
+            ehci->sofv &= 0x000003ff;
+        }
+
+        if (frames - i > 10)
+            skipped_frames++;
+        else {
+            // TODO could this cause periodic frames to get skipped if async
+            // active?
+            if (ehci->astate != EST_EXECUTING)
+                ehci_advance_periodic_state(ehci);
+        }
+
+#ifdef EHCI_NOMICROFRAMES
+        ehci->last_run_usec += 1000;
+#else
+        ehci->last_run_usec += 125;
+#endif
+    }
+
+#if 0
+    if (skipped_frames)
+        DEBUG(("WARNING - EHCI skipped %d frames\n", skipped_frames));
+#endif
+
+    /*  Async is not inside loop since it executes everything it can once
+     *  called
+     */
+    if (ehci->pstate != EST_EXECUTING)
+        ehci_advance_async_state(ehci);
+
+    qemu_mod_timer(ehci->frame_timer, expire_time);
+
+    usec_elapsed = qemu_get_clock(vm_clock) / 1000 - usec_now;
+
+#ifdef TDEBUG
+    DEBUG(("TIMING: frame_timer used %d usec\n", usec_elapsed));
+#endif
+}
+
+static CPUReadMemoryFunc *ehci_readfn[3]={
+    ehci_mem_readb,
+    ehci_mem_readw,
+    ehci_mem_readl
+};
+
+static CPUWriteMemoryFunc *ehci_writefn[3]={
+    ehci_mem_writeb,
+    ehci_mem_writew,
+    ehci_mem_writel
+};
+
+static void ehci_map(PCIDevice *pci_dev, int region_num,
+                    pcibus_t addr, pcibus_t size, int type)
+{
+    EHCIState *s =(EHCIState *)pci_dev;
+
+    DEBUG(("ehci_map: region %d, addr %08lX, size %ld, s->mem %08X\n",
+            region_num, addr, size, s->mem));
+    s->mem_base = addr;
+    cpu_register_physical_memory(addr, size, s->mem);
+}
+
+static int usb_ehci_initfn(PCIDevice *dev);
+
+static PCIDeviceInfo ehci_info[] = {
+    {
+        .qdev.name    = "usb-ehci",
+        .qdev.size    = sizeof(EHCIState),
+        .init         = usb_ehci_initfn,
+    },{
+        /* end of list */
+    }
+};
+
+#if 0
+void usb_ehci_info(Monitor *mon)
+{
+    int i;
+    uint32_t val;
+    static uint32_t last[0x64 + NB_PORTS * 4];
+
+    for(i = 0; i <= 0x64 + NB_PORTS * 4; i+=4) {
+        val = *(uint32_t *) &(ehci_info->mmio[i]);
+
+        monitor_printf(mon, "MMIO %08X : %08X   [+/- %08X]\n", i, val, val ^ last[i/4]);
+        last[i/4] = val;
+    }
+}
+#else
+void usb_ehci_info(Monitor *mon)
+{
+    monitor_printf(mon, "USB EHCI info not implemented yet\n");
+}
+#endif
+
+static int usb_ehci_initfn(PCIDevice *dev)
+{
+    EHCIState *s = DO_UPCAST(EHCIState, dev, dev);
+    uint8_t *pci_conf = s->dev.config;
+    int i;
+
+    pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_INTEL);
+    pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_INTEL_82801D);
+    pci_conf[PCI_REVISION_ID] = 0x10;
+    pci_conf[PCI_CLASS_PROG] = 0x20;
+    pci_config_set_class(pci_conf, PCI_CLASS_SERIAL_USB);
+
+    pci_conf[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_NORMAL;
+    pci_conf[PCI_CAPABILITY_LIST] = 0x00; // capabilities pointer
+
+    // pci_conf[0x34] = 0x50; // capabilities pointer
+
+    pci_conf[0x3d] = 4; // interrupt pin 3
+    pci_conf[0x3e] = 0; // MaxLat
+    pci_conf[0x3f] = 0; // MinGnt
+
+    // pci_conf[0x50] = 0x01; // power management caps
+
+    pci_conf[0x60] = 0x20;  // SBRN
+    pci_conf[0x61] = 0x20;  // FLADJ
+    pci_conf[0x62] = 0x7f;
+    pci_conf[0x63] = 0x00;  // PORTWAKECAP
+    pci_conf[0x64] = 0x00;
+    pci_conf[0x65] = 0x00;
+    pci_conf[0x66] = 0x00;
+    pci_conf[0x67] = 0x00;
+    pci_conf[0x68] = 0x01;
+    pci_conf[0x69] = 0x00;
+    pci_conf[0x6a] = 0x00;
+    pci_conf[0x6b] = 0x00;  // USBLEGSUP
+    pci_conf[0x6c] = 0x00;
+    pci_conf[0x6d] = 0x00;
+    pci_conf[0x6e] = 0x00;
+    pci_conf[0x6f] = 0xc0;  // USBLEFCTLSTS
+
+    s->mmio[0x00] = OPREGBASE;
+    s->mmio[0x01] = 0x00;
+    s->mmio[0x02] = 0x00;
+    s->mmio[0x03] = 0x01;    // HC version
+    s->mmio[0x04] = NB_PORTS;  // Number of downstream ports
+    s->mmio[0x05] = 0x00;    // No companion ports at present
+    s->mmio[0x06] = 0x00;
+    s->mmio[0x07] = 0x00;
+    s->mmio[0x08] = 0x80;    // We can cache whole frame, not 64-bit capable
+    s->mmio[0x09] = 0x68;    // EECP
+    s->mmio[0x0a] = 0x00;
+    s->mmio[0x0b] = 0x00;
+
+    s->irq = s->dev.irq[0];
+
+    // TODO - port registration is going to need an overhaul since ports
+    // can be low, full or high speed and are not tied to UHCI or EHCI.
+    // This works for now since we register last so are top of the free
+    // list but really all ports need to be owned by EHCI and it should
+    // hand off to companion controllers if device is full or low speed.
+
+    DEBUG(("ehci init : registering USB ports with no device attached\n"));
+
+    // TODO come up with a better port allocation scheme
+    // added ehci->bus, need to find ehci->DeviceState
+    usb_bus_new(&s->bus, &s->dev.qdev);
+    for(i = 0; i < NB_PORTS; i++) {
+        usb_register_port(&s->bus, &s->ports[i], s, i, ehci_attach);
+        s->ports[i].dev = 0;
+    }
+
+    s->frame_timer = qemu_new_timer(vm_clock, ehci_frame_timer, s);
+
+    qemu_register_reset(ehci_reset, s);
+
+    s->mem = cpu_register_io_memory(ehci_readfn, ehci_writefn, s);
+
+    DEBUG(("ehci init : registering MMIO size %d\n", MMIO_SIZE));
+    pci_register_bar(&s->dev, 0, MMIO_SIZE, PCI_BASE_ADDRESS_SPACE_MEMORY,
+                                                            ehci_map);
+
+    DEBUG(("*** ehci init : under development 16-OCT-08 *** \n"));
+
+    return 0;
+}
+
+static void ehci_register(void)
+{
+    pci_qdev_register_many(ehci_info);
+}
+device_init(ehci_register);
+
+void usb_ehci_init(PCIBus *bus, int devfn)
+{
+    pci_create_simple(bus, devfn, "usb-ehci");
+}
+
+/*
+ * vim: expandtab ts=4
+ */
diff --git a/hw/usb-ehci.h b/hw/usb-ehci.h
new file mode 100644
index 0000000..15d74d2
--- /dev/null
+++ b/hw/usb-ehci.h
@@ -0,0 +1,9 @@ 
+#ifndef QEMU_USB_EHCI_H
+#define QEMU_USB_EHCI_H
+
+#include "qemu-common.h"
+
+void usb_ehci_info(Monitor *mon);
+void usb_ehci_init(PCIBus *bus, int devfn);
+
+#endif
diff --git a/monitor.c b/monitor.c
index a49e3f0..ae4ff1f 100644
--- a/monitor.c
+++ b/monitor.c
@@ -25,6 +25,7 @@ 
 #include "hw/hw.h"
 #include "hw/qdev.h"
 #include "hw/usb.h"
+#include "hw/usb-ehci.h"
 #include "hw/pcmcia.h"
 #include "hw/pc.h"
 #include "hw/pci.h"
@@ -2752,6 +2753,13 @@  static const mon_cmd_t info_cmds[] = {
         .mhandler.info = usb_host_info,
     },
     {
+        .name       = "usbehci",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show ehci status",
+        .mhandler.info = usb_ehci_info,
+    },
+    {
         .name       = "profile",
         .args_type  = "",
         .params     = "",