Patchwork [V1,3/8] Implementation of the TCG BIOS extensions

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Submitter Stefan Berger
Date March 30, 2011, 5:55 p.m.
Message ID <20110330175558.859356867@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/88946/
State New
Headers show

Comments

Stefan Berger - March 30, 2011, 5:55 p.m.
This patch implements the main part of the TCG BIOS extensions. It provides
the following functionality:

- initialization of the TCPA ACPI table used for logging of measurements
- initialization of the TPM by sending a sequence of commands to it
- proper setup of the TPM once the BIOS hands over control to the bootloader
- support for S3 resume; BIOS sends TPM_Startup(ST_STATE) to TPM
- a utility function called mssleep is added. It waits for a number
  of milliseconds before it returns. I had tried to build a function
  like that based on calc_future_time() and check_timer(), but those
  didn't work once in an S3 resume.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

---
 src/boot.c    |    2 
 src/post.c    |    5 
 src/resume.c  |    2 
 src/tcgbios.c |  525 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/tcgbios.h |  386 ++++++++++++++++++++++++++++++++++++++++++
 src/util.c    |   18 +
 src/util.h    |    5 
 7 files changed, 943 insertions(+)
Kevin O'Connor - April 4, 2011, 4:14 a.m.
Hi Stefan,

I haven't had a chance to fully review, but I do have some comments.

On Wed, Mar 30, 2011 at 01:55:37PM -0400, Stefan Berger wrote:
[...]
> - a utility function called mssleep is added. It waits for a number
>   of milliseconds before it returns. I had tried to build a function
>   like that based on calc_future_time() and check_timer(), but those
>   didn't work once in an S3 resume.

There is already msleep() for this.  The inb(0x61) thing doesn't
actually work anywhere but on bochs.  If msleep() isn't working for
you, try rerunning calibrate_tsc() after S3 resume.

[...]
> +/*
> + *  Implementation of the TCG BIOS extension according to the specification
> + *  described in
> + *  https://www.trustedcomputinggroup.org/specs/PCClient/TCG_PCClientImplementationforBIOS_1-20_1-00.pdf
> + *
> + *  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.

SeaBIOS is LGPLv3.  Also, I'm not a big fan of these big copyright
notices on the top of every file - is it necessary?

[...]
> +#if CONFIG_TCGBIOS

I'd prefer to avoid ifdefs in the code.  Everything should be setup to
have the compiler/linker automatically drop anything unused.  (So, a
simple "if (!CONFIG_TCGBIOS) return;" should drop any function and all
variables/functions only reachable from it.)

[...]
> +//#define DEBUG_TCGBIOS

Same here.  Can you use just set DEBUG_tcg to a value in config.h and
replace all the dprintf(1, ...) with dprintf(DEBUG_tcg, ...)?

> +static u8
> +calc_checksum(const u8 *addr, u32 length)

util.c:checksum()

> +static struct rsdp_descriptor *
> +find_rsdp(u8 *start, unsigned int len)

Should be unneeded - see how acpi.c:find_resume_vector() works.

-Kevin
Stefan Berger - April 4, 2011, 2:49 p.m.
On 04/04/2011 12:14 AM, Kevin O'Connor wrote:
> Hi Stefan,
>
> I haven't had a chance to fully review, but I do have some comments.
Thanks. I can post a v2 as a followup to your changes.
> On Wed, Mar 30, 2011 at 01:55:37PM -0400, Stefan Berger wrote:
> [...]
>> - a utility function called mssleep is added. It waits for a number
>>    of milliseconds before it returns. I had tried to build a function
>>    like that based on calc_future_time() and check_timer(), but those
>>    didn't work once in an S3 resume.
> There is already msleep() for this.  The inb(0x61) thing doesn't
> actually work anywhere but on bochs.  If msleep() isn't working for
> you, try rerunning calibrate_tsc() after S3 resume.
Using that one now.
> [...]
>> +/*
>> + *  Implementation of the TCG BIOS extension according to the specification
>> + *  described in
>> + *  https://www.trustedcomputinggroup.org/specs/PCClient/TCG_PCClientImplementationforBIOS_1-20_1-00.pdf
>> + *
>> + *  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.
> SeaBIOS is LGPLv3.  Also, I'm not a big fan of these big copyright
> notices on the top of every file - is it necessary?
I will change it to look like the other files.
> [...]
>> +#if CONFIG_TCGBIOS
> I'd prefer to avoid ifdefs in the code.  Everything should be setup to
> have the compiler/linker automatically drop anything unused.  (So, a
> simple "if (!CONFIG_TCGBIOS) return;" should drop any function and all
> variables/functions only reachable from it.)
Ok, I will adapt it to that.
> [...]
>> +//#define DEBUG_TCGBIOS
> Same here.  Can you use just set DEBUG_tcg to a value in config.h and
> replace all the dprintf(1, ...) with dprintf(DEBUG_tcg, ...)?

Did that now.
>> +static u8
>> +calc_checksum(const u8 *addr, u32 length)
> util.c:checksum()
Using that one.
>> +static struct rsdp_descriptor *
>> +find_rsdp(u8 *start, unsigned int len)
> Should be unneeded - see how acpi.c:find_resume_vector() works.
I was going to keep the function find_rsdp but change its implementation 
to the test you are doing in find_resume_vector() regarding rsdp signature.

    Stefan

> -Kevin
>

Patch

Index: seabios/src/tcgbios.c
===================================================================
--- /dev/null
+++ seabios/src/tcgbios.c
@@ -0,0 +1,525 @@ 
+/*
+ *  Implementation of the TCG BIOS extension according to the specification
+ *  described in
+ *  https://www.trustedcomputinggroup.org/specs/PCClient/TCG_PCClientImplementationforBIOS_1-20_1-00.pdf
+ *
+ *  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
+ *
+ * Copyright (C) IBM Corporation, 2006,2010,2011
+ *
+ * Author: Stefan Berger <stefanb@us.ibm.com>
+ */
+
+#include "config.h"
+
+#if CONFIG_TCGBIOS
+
+#include "types.h"
+#include "tpm_drivers.h" // tpm_drivers[]
+#include "util.h" // printf, get_keystroke
+#include "tcgbios.h"// tcpa_*, prototypes
+#include "acpi.h"  // RSDP_SIGNATURE, rsdt_descriptor
+#include "smbios.h" // smbios_entry_point
+
+
+//#define DEBUG_TCGBIOS
+
+static const u8 Startup_ST_CLEAR[2] = { 0x00, TPM_ST_CLEAR };
+static const u8 Startup_ST_STATE[2] = { 0x00, TPM_ST_STATE };
+
+static const u8 PhysicalPresence_CMD_ENABLE[2]  = { 0x00, 0x20 };
+static const u8 PhysicalPresence_CMD_DISABLE[2] = { 0x01, 0x00 };
+static const u8 PhysicalPresence_PRESENT[2]     = { 0x00, 0x08 };
+static const u8 PhysicalPresence_NOT_PRESENT[2] = { 0x00, 0x10 };
+static const u8 PhysicalPresence_LOCK[2]        = { 0x00, 0x04 };
+
+static const u8 CommandFlag_FALSE[1] = { 0x00 };
+static const u8 CommandFlag_TRUE[1]  = { 0x01 };
+
+static const u8 GetCapability_Permanent_Flags[12] = {
+    0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x04,
+    0x00, 0x00, 0x01, 0x08
+};
+
+static const u8 GetCapability_OwnerAuth[12] = {
+    0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x04,
+    0x00, 0x00, 0x01, 0x11
+};
+
+
+#define RSDP_CAST(ptr)   ((struct rsdp_descriptor *)ptr)
+
+
+/* helper functions */
+
+static inline void *input_buf32(struct bregs *regs)
+{
+    return MAKE_FLATPTR(regs->es, regs->di);
+}
+
+static inline void *output_buf32(struct bregs *regs)
+{
+    return MAKE_FLATPTR(regs->ds, regs->si);
+}
+
+
+typedef struct {
+    u8            tpm_probed:1;
+    u8            tpm_found:1;
+    u8            tpm_working:1;
+    u8            if_shutdown:1;
+    u8            tpm_driver_to_use:4;
+} tcpa_state_t;
+
+
+static tcpa_state_t tcpa_state = {
+    .tpm_driver_to_use = TPM_INVALID_DRIVER,
+};
+
+extern struct tpm_driver tpm_drivers[];
+
+
+/********************************************************
+  Extensions for TCG-enabled BIOS
+ *******************************************************/
+
+
+static u32
+is_tpm_present(void)
+{
+    u32 rc = 0;
+    unsigned int i;
+
+    for (i = 0; i < TPM_NUM_DRIVERS; i++) {
+        struct tpm_driver *td = &tpm_drivers[i];
+        if (td->probe() != 0) {
+            td->init();
+            tcpa_state.tpm_driver_to_use = i;
+            rc = 1;
+            break;
+        }
+    }
+
+    return rc;
+}
+
+
+int
+has_working_tpm(void)
+{
+    if (!tcpa_state.tpm_probed) {
+        tcpa_state.tpm_probed = 1;
+        tcpa_state.tpm_found = (is_tpm_present() != 0);
+        tcpa_state.tpm_working = 1;
+    }
+    if (!tcpa_state.tpm_working)
+        return 0;
+
+    return tcpa_state.tpm_found;
+}
+
+
+static u8
+calc_checksum(const u8 *addr, u32 length)
+{
+    u8 sum = 0;
+    u32 ctr;
+
+    for (ctr = 0; ctr < length; ctr++)
+        sum += addr[ctr];
+
+    return sum;
+}
+
+
+/*
+ * Search for the RSDP ACPI table in the memory starting at addr and
+ * ending at addr + len - 1.
+ */
+static struct rsdp_descriptor *
+find_rsdp(u8 *start, unsigned int len)
+{
+    u8 *end = start + len;
+
+    /* scan memory in steps of 16 bytes */
+    while (start < end) {
+        /* check for expected string */
+        if (RSDP_CAST(start)->signature == RSDP_SIGNATURE &&
+            calc_checksum(start,
+                          sizeof(struct rsdp_descriptor)) == 0)
+            return RSDP_CAST(start);
+        start += 0x10;
+    }
+
+    return 0;
+}
+
+
+
+
+static struct tcpa_descriptor_rev2 *
+find_tcpa_by_rsdp(struct rsdp_descriptor *rsdp)
+{
+    u32 ctr = 0;
+    struct tcpa_descriptor_rev2 *tcpa = NULL;
+    struct rsdt_descriptor *rsdt;
+    u32 length;
+    u16 off;
+
+    rsdt   = (struct rsdt_descriptor *)rsdp->rsdt_physical_address;
+    if (!rsdt)
+        return NULL;
+
+    length = rsdt->length;
+    off = offsetof(struct rsdt_descriptor, entry);
+
+    while ((off + sizeof(rsdt->entry[0])) <= length) {
+        /* try all pointers to structures */
+        tcpa = (struct tcpa_descriptor_rev2 *)(int)rsdt->entry[ctr];
+
+        /* valid TCPA ACPI table ? */
+        if (tcpa->signature == TCPA_SIGNATURE &&
+            calc_checksum((u8 *)tcpa, tcpa->length) == 0)
+            break;
+
+        tcpa = NULL;
+        off += sizeof(rsdt->entry[0]);
+        ctr++;
+    }
+
+    return tcpa;
+}
+
+
+static struct tcpa_descriptor_rev2 *
+find_tcpa_table(void)
+{
+    struct tcpa_descriptor_rev2 *tcpa = NULL;
+    struct rsdp_descriptor *rsdp;
+    u16 ebda_seg;
+
+    /* RSDP in EBDA? */
+    ebda_seg = *(u16 *)MAKE_FLATPTR(0x40, 0xe);
+    rsdp = find_rsdp(MAKE_FLATPTR(ebda_seg, 0), 1024);
+
+    if (rsdp)
+        tcpa = find_tcpa_by_rsdp(rsdp);
+
+    if (!tcpa) {
+        rsdp = find_rsdp((u8 *)0xE0000, 0x20000);
+        if (rsdp)
+            tcpa = find_tcpa_by_rsdp(rsdp);
+    }
+
+    if (!rsdp)
+        tcpa_state.if_shutdown = 1;
+
+#ifdef DEBUG_TCGBIOS
+    if (! rsdp )
+        dprintf(1, "TCGBIOS: RSDP was NOT found! -- Disabling interface.\n");
+    else if ( !tcpa )
+        dprintf(1, "TCGBIOS: TCPA ACPI was NOT found!\n");
+#endif
+
+    return tcpa;
+}
+
+
+static u8 *
+get_lasa_base_ptr(u32 *laml)
+{
+    u8 *lasa = 0;
+    struct tcpa_descriptor_rev2 *tcpa = find_tcpa_table();
+
+    if (tcpa) {
+        lasa = (u8 *)(long)tcpa->lasa;
+        if (laml)
+            *laml = tcpa->laml;
+    }
+
+    return lasa;
+}
+
+
+/* clear the ACPI log */
+static void
+reset_acpi_log(void)
+{
+    u32 laml;
+    u8 *lasa = get_lasa_base_ptr(&laml);
+
+    if (lasa)
+        memset(lasa, 0x0, laml);
+}
+
+
+/*
+   initialize the TCPA ACPI subsystem; find the ACPI tables and determine
+   where the TCPA table is.
+ */
+void
+tcpa_acpi_init(void)
+{
+    tcpa_state.if_shutdown = 0;
+    tcpa_state.tpm_probed = 0;
+    tcpa_state.tpm_found = 0;
+    tcpa_state.tpm_working = 0;
+
+    if (!has_working_tpm()) {
+        tcpa_state.if_shutdown = 1;
+        return;
+    }
+
+    reset_acpi_log();
+}
+
+
+static u32
+transmit(u8 locty, const struct iovec iovec[],
+         u8 *respbuffer, u32 *respbufferlen)
+{
+    u32 rc = 0;
+    u32 irc;
+    struct tpm_driver *td;
+    unsigned int i;
+
+    if (tcpa_state.tpm_driver_to_use == TPM_INVALID_DRIVER)
+        return TCG_FATAL_COM_ERROR;
+
+    td = &tpm_drivers[tcpa_state.tpm_driver_to_use];
+
+    irc = td->activate(locty);
+    if (irc != 0) {
+        /* tpm could not be activated */
+        return TCG_FATAL_COM_ERROR;
+    }
+
+    for (i = 0; iovec[i].length; i++) {
+        irc = td->senddata(iovec[i].data,
+                           iovec[i].length);
+        if (irc != 0)
+            return TCG_FATAL_COM_ERROR;
+    }
+
+    irc = td->waitdatavalid();
+    if (irc != 0)
+        return TCG_FATAL_COM_ERROR;
+
+    irc = td->waitrespready(10000);
+    if (irc != 0)
+        return TCG_FATAL_COM_ERROR;
+
+    irc = td->readresp(respbuffer,
+                       respbufferlen);
+    if (irc != 0)
+        return TCG_FATAL_COM_ERROR;
+
+    td->ready();
+
+    return rc;
+}
+
+
+/*
+ * Send a TPM command with the given ordinal. Append the given buffer
+ * containing all data in network byte order to the command (this is
+ * the custom part per command) and expect a response of the given size.
+ * If a buffer is provided, the response will be copied into it.
+ */
+static u32
+build_and_send_cmd_od(u32 ordinal, const u8 *append, u32 append_size,
+                      u8 *resbuffer, u32 return_size, u32 *returnCode,
+                      const u8 *otherdata, u32 otherdata_size)
+{
+#define MAX_APPEND_SIZE   12
+#define MAX_RESPONSE_SIZE sizeof(struct tpm_res_getcap_perm_flags)
+    u32 rc;
+    u8 ibuffer[TPM_REQ_HEADER_SIZE + MAX_APPEND_SIZE];
+    u8 obuffer[MAX_RESPONSE_SIZE];
+    struct tpm_req_header *trqh = (struct tpm_req_header *)ibuffer;
+    struct tpm_rsp_header *trsh = (struct tpm_rsp_header *)obuffer;
+    u8 locty = 0;
+    struct iovec iovec[3];
+    u32 obuffer_len = sizeof(obuffer);
+    u32 idx = 1;
+
+    if (append_size > MAX_APPEND_SIZE ||
+        return_size > MAX_RESPONSE_SIZE) {
+#ifdef DEBUG_TCGBIOS
+        dprintf(1, "TCGBIOS: size of requested buffers too big.");
+#endif
+        return TCG_FIRMWARE_ERROR;
+    }
+
+    iovec[0].data   = trqh;
+    iovec[0].length = TPM_REQ_HEADER_SIZE + append_size;
+
+    if (otherdata) {
+        iovec[1].data   = (void *)otherdata;
+        iovec[1].length = otherdata_size;
+        idx = 2;
+    }
+
+    iovec[idx].data   = NULL;
+    iovec[idx].length = 0;
+
+    memset(ibuffer, 0x0, sizeof(ibuffer));
+    memset(obuffer, 0x0, sizeof(obuffer));
+
+    trqh->tag     = htons(0xc1);
+    trqh->totlen  = htonl(TPM_REQ_HEADER_SIZE + append_size + otherdata_size);
+    trqh->ordinal = htonl(ordinal);
+
+    if (append_size)
+        memcpy((char *)trqh + sizeof(*trqh),
+               append, append_size);
+
+    rc = transmit(locty, iovec, obuffer, &obuffer_len);
+    if (rc)
+        return rc;
+
+    *returnCode = ntohl(trsh->errcode);
+
+    if (resbuffer)
+        memcpy(resbuffer, trsh, return_size);
+
+    return 0;
+}
+
+
+static u32
+build_and_send_cmd(u32 ordinal, const u8 *append, u32 append_size,
+                   u8 *resbuffer, u32 return_size, u32 *returnCode)
+{
+    return build_and_send_cmd_od(ordinal, append, append_size,
+                                 resbuffer, return_size, returnCode,
+                                 NULL, 0);
+}
+
+
+u32
+tcpa_startup(void)
+{
+    u32 rc = 0;
+    u32 returnCode;
+
+    if (!has_working_tpm())
+        return 0;
+
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"TCGBIOS: Starting with TPM_Startup(ST_CLEAR)\n");
+#endif
+    rc = build_and_send_cmd(TPM_ORD_Startup,
+                            Startup_ST_CLEAR, sizeof(Startup_ST_CLEAR),
+                            NULL, 10, &returnCode);
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"Return code from TPM_Startup = 0x%08x\n",
+              returnCode);
+#endif
+    if (rc && returnCode)
+        goto err_exit;
+
+    rc = build_and_send_cmd(TPM_ORD_SelfTestFull, NULL, 0,
+                            NULL, 10, &returnCode);
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"Return code from TPM_SelfTestFull = 0x%08x\n",
+              returnCode);
+#endif
+    if (rc || returnCode)
+        goto err_exit;
+
+    return 0;
+
+err_exit:
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"TCGBIOS: TPM malfunctioning (line %d).\n", __LINE__);
+#endif
+    tcpa_state.tpm_working = 0;
+    if (rc)
+        return rc;
+    return TCG_TCG_COMMAND_ERROR;
+}
+
+
+u32
+tcpa_leave_bios(void)
+{
+    u32 rc = 0;
+    u32 returnCode;
+
+    if (!has_working_tpm())
+        return 0;
+
+    rc = build_and_send_cmd(TPM_ORD_PhysicalPresence,
+                            PhysicalPresence_CMD_ENABLE,
+                            sizeof(PhysicalPresence_CMD_ENABLE),
+                            NULL, 10, &returnCode);
+    if (rc || returnCode)
+        goto err_exit;
+
+    rc = build_and_send_cmd(TPM_ORD_PhysicalPresence,
+                            PhysicalPresence_NOT_PRESENT,
+                            sizeof(PhysicalPresence_NOT_PRESENT),
+                            NULL, 10, &returnCode);
+    if (rc || returnCode)
+        goto err_exit;
+
+    return 0;
+
+err_exit:
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"TCGBIOS: TPM malfunctioning (line %d).\n", __LINE__);
+#endif
+    tcpa_state.tpm_working = 0;
+    if (rc)
+        return rc;
+    return TCG_TCG_COMMAND_ERROR;
+}
+
+
+u32
+tcpa_s3_resume(void)
+{
+    u32 rc = 0;
+    u32 returnCode;
+
+    if (has_working_tpm()) {
+        rc = build_and_send_cmd(TPM_ORD_Startup,
+                                Startup_ST_STATE,
+                                sizeof(Startup_ST_STATE),
+                                NULL, 10, &returnCode);
+#ifdef DEBUG_TCGBIOS
+        dprintf(1,"TCGBIOS: Resuming with TPM_Startup(ST_STATE)\n");
+        dprintf(1,"TCGBIOS: ReturnCode from TPM_Startup = 0x%08x\n",
+                  returnCode);
+#endif
+        if (rc || returnCode)
+            goto err_exit;
+    }
+
+    return 0;
+
+err_exit:
+#ifdef DEBUG_TCGBIOS
+    dprintf(1,"TCGBIOS: TPM malfunctioning (line %d).\n", __LINE__);
+#endif
+    tcpa_state.tpm_working = 0;
+    if (rc)
+        return rc;
+    return TCG_TCG_COMMAND_ERROR;
+}
+
+
+#endif /* CONFIG_TCGBIOS */
Index: seabios/src/tcgbios.h
===================================================================
--- /dev/null
+++ seabios/src/tcgbios.h
@@ -0,0 +1,386 @@ 
+#ifndef TCGBIOS_H
+#define TCGBIOS_H
+
+#include "types.h"
+#include "bregs.h" /* struct bregs */
+
+#define TCG_MAGIC 0x41504354L
+
+/* Define for section 12.3 */
+#define TCG_PC_OK                       0x0
+#define TCG_PC_TPMERROR                 0x1
+#define TCG_PC_LOGOVERFLOW              0x2
+#define TCG_PC_UNSUPPORTED              0x3
+
+#define TPM_ALG_SHA                     0x4
+
+#define TCG_MAGIC                       0x41504354L
+#define TCG_VERSION_MAJOR               1
+#define TCG_VERSION_MINOR               2
+
+#define TPM_OK                          0x0
+#define TPM_RET_BASE                    0x1
+#define TCG_GENERAL_ERROR               (TPM_RET_BASE + 0x0)
+#define TCG_TPM_IS_LOCKED               (TPM_RET_BASE + 0x1)
+#define TCG_NO_RESPONSE                 (TPM_RET_BASE + 0x2)
+#define TCG_INVALID_RESPONSE            (TPM_RET_BASE + 0x3)
+#define TCG_INVALID_ACCESS_REQUEST      (TPM_RET_BASE + 0x4)
+#define TCG_FIRMWARE_ERROR              (TPM_RET_BASE + 0x5)
+#define TCG_INTEGRITY_CHECK_FAILED      (TPM_RET_BASE + 0x6)
+#define TCG_INVALID_DEVICE_ID           (TPM_RET_BASE + 0x7)
+#define TCG_INVALID_VENDOR_ID           (TPM_RET_BASE + 0x8)
+#define TCG_UNABLE_TO_OPEN              (TPM_RET_BASE + 0x9)
+#define TCG_UNABLE_TO_CLOSE             (TPM_RET_BASE + 0xa)
+#define TCG_RESPONSE_TIMEOUT            (TPM_RET_BASE + 0xb)
+#define TCG_INVALID_COM_REQUEST         (TPM_RET_BASE + 0xc)
+#define TCG_INVALID_ADR_REQUEST         (TPM_RET_BASE + 0xd)
+#define TCG_WRITE_BYTE_ERROR            (TPM_RET_BASE + 0xe)
+#define TCG_READ_BYTE_ERROR             (TPM_RET_BASE + 0xf)
+#define TCG_BLOCK_WRITE_TIMEOUT         (TPM_RET_BASE + 0x10)
+#define TCG_CHAR_WRITE_TIMEOUT          (TPM_RET_BASE + 0x11)
+#define TCG_CHAR_READ_TIMEOUT           (TPM_RET_BASE + 0x12)
+#define TCG_BLOCK_READ_TIMEOUT          (TPM_RET_BASE + 0x13)
+#define TCG_TRANSFER_ABORT              (TPM_RET_BASE + 0x14)
+#define TCG_INVALID_DRV_FUNCTION        (TPM_RET_BASE + 0x15)
+#define TCG_OUTPUT_BUFFER_TOO_SHORT     (TPM_RET_BASE + 0x16)
+#define TCG_FATAL_COM_ERROR             (TPM_RET_BASE + 0x17)
+#define TCG_INVALID_INPUT_PARA          (TPM_RET_BASE + 0x18)
+#define TCG_TCG_COMMAND_ERROR           (TPM_RET_BASE + 0x19)
+#define TCG_INTERFACE_SHUTDOWN          (TPM_RET_BASE + 0x20)
+//define TCG_PC_UNSUPPORTED             (TPM_RET_BASE + 0x21)
+#define TCG_PC_TPM_NOT_PRESENT          (TPM_RET_BASE + 0x22)
+#define TCG_PC_TPM_DEACTIVATED          (TPM_RET_BASE + 0x23)
+
+
+#define TPM_INVALID_ADR_REQUEST          TCG_INVALID_ADR_REQUEST
+#define TPM_IS_LOCKED                    TCG_TPM_IS_LOCKED
+#define TPM_INVALID_DEVICE_ID            TCG_INVALID_DEVICE_ID
+#define TPM_INVALID_VENDOR_ID            TCG_INVALID_VENDOR_ID
+//define TPM_RESERVED_REG_INVALID
+#define TPM_FIRMWARE_ERROR               TCG_FIRMWARE_ERROR
+#define TPM_UNABLE_TO_OPEN               TCG_UNABLE_TO_OPEN
+#define TPM_UNABLE_TO_CLOSE              TCG_UNABLE_TO_CLOSE
+#define TPM_INVALID_RESPONSE             TCG_INVALID_RESPONSE
+#define TPM_RESPONSE_TIMEOUT             TCG_RESPONSE_TIMEOUT
+#define TPM_INVALID_ACCESS_REQUEST       TCG_INVALID_ACCESS_REQUEST
+#define TPM_TRANSFER_ABORT               TCG_TRANSFER_ABORT
+#define TPM_GENERAL_ERROR                TCG_GENERAL_ERROR
+
+
+#define TPM_ORD_SelfTestFull             0x00000050
+#define TPM_ORD_ForceClear               0x0000005d
+#define TPM_ORD_GetCapability            0x00000065
+#define TPM_ORD_PhysicalEnable           0x0000006f
+#define TPM_ORD_PhysicalDisable          0x00000070
+#define TPM_ORD_SetOwnerInstall          0x00000071
+#define TPM_ORD_PhysicalSetDeactivated   0x00000072
+#define TPM_ORD_Startup                  0x00000099
+#define TPM_ORD_PhysicalPresence         0x4000000a
+#define TPM_ORD_Extend                   0x00000014
+#define TPM_ORD_SHA1Start                0x000000a0
+#define TPM_ORD_SHA1Update               0x000000a1
+#define TPM_ORD_SHA1Complete             0x000000a2
+
+
+#define TPM_ST_CLEAR                     0x1
+#define TPM_ST_STATE                     0x2
+#define TPM_ST_DEACTIVATED               0x3
+
+
+/* interrupt identifiers (al register) */
+enum irq_ids {
+    TCG_StatusCheck = 0,
+    TCG_HashLogExtendEvent = 1,
+    TCG_PassThroughToTPM = 2,
+    TCG_ShutdownPreBootInterface = 3,
+    TCG_HashLogEvent = 4,
+    TCG_HashAll = 5,
+    TCG_TSS = 6,
+    TCG_CompactHashLogExtendEvent = 7,
+};
+
+/* event types: 10.4.1 / table 11 */
+#define EV_POST_CODE             1
+#define EV_SEPARATOR             4
+#define EV_ACTION                5
+#define EV_EVENT_TAG             6
+#define EV_COMPACT_HASH         12
+#define EV_IPL                  13
+#define EV_IPL_PARTITION_DATA   14
+
+
+#define STATUS_FLAG_SHUTDOWN        (1 << 0)
+
+#define SHA1_BUFSIZE                20
+
+
+struct iovec
+{
+    size_t length;
+    void   *data;
+};
+
+
+/* Input and Output blocks for the TCG BIOS commands */
+
+struct hleei_short
+{
+    u16   ipblength;
+    u16   reserved;
+    const void *hashdataptr;
+    u32   hashdatalen;
+    u32   pcrindex;
+    const void *logdataptr;
+    u32   logdatalen;
+} PACKED;
+
+
+struct hleei_long
+{
+    u16   ipblength;
+    u16   reserved;
+    void *hashdataptr;
+    u32   hashdatalen;
+    u32   pcrindex;
+    u32   reserved2;
+    void *logdataptr;
+    u32   logdatalen;
+} PACKED;
+
+
+struct hleeo
+{
+    u16    opblength;
+    u16    reserved;
+    u32    eventnumber;
+    u8     digest[SHA1_BUFSIZE];
+} PACKED;
+
+
+struct pttti
+{
+    u16    ipblength;
+    u16    reserved;
+    u16    opblength;
+    u16    reserved2;
+    u8     tpmopin[0];
+} PACKED;
+
+
+struct pttto
+{
+    u16    opblength;
+    u16    reserved;
+    u8     tpmopout[0];
+};
+
+
+struct hlei
+{
+    u16    ipblength;
+    u16    reserved;
+    const void  *hashdataptr;
+    u32    hashdatalen;
+    u32    pcrindex;
+    u32    logeventtype;
+    const void  *logdataptr;
+    u32    logdatalen;
+} PACKED;
+
+
+struct hleo
+{
+    u16    opblength;
+    u16    reserved;
+    u32    eventnumber;
+} PACKED;
+
+
+struct hai
+{
+    u16    ipblength;
+    u16    reserved;
+    const void  *hashdataptr;
+    u32    hashdatalen;
+    u32    algorithmid;
+} PACKED;
+
+
+struct ti
+{
+    u16    ipblength;
+    u16    reserved;
+    u16    opblength;
+    u16    reserved2;
+    u8     tssoperandin[0];
+} PACKED;
+
+
+struct to
+{
+    u16    opblength;
+    u16    reserved;
+    u8     tssoperandout[0];
+} PACKED;
+
+
+struct pcpes
+{
+    u32    pcrindex;
+    u32    eventtype;
+    u8     digest[SHA1_BUFSIZE];
+    u32    eventdatasize;
+    u32    event;
+} PACKED;
+
+
+/* 10.4.2.1 */
+struct pcctes
+{
+    u32 eventid;
+    u32 eventdatasize;
+    u8  digest[SHA1_BUFSIZE];
+} PACKED;
+
+/* 10.4.2.1 w/ 10.4.2.2.1 embedded */
+struct pcctes_romex
+{
+    u32 eventid;
+    u32 eventdatasize;
+    u16 reserved;
+    u16 pfa;
+    u8  digest[SHA1_BUFSIZE];
+} PACKED;
+
+
+#define TPM_REQ_HEADER \
+    u16    tag; \
+    u32    totlen; \
+    u32    ordinal;
+
+#define TPM_REQ_HEADER_SIZE  (sizeof(u16) + sizeof(u32) + sizeof(u32))
+
+#define TPM_RSP_HEADER \
+    u16    tag; \
+    u32    totlen; \
+    u32    errcode;
+
+#define TPM_RSP_HEADER_SIZE  (sizeof(u16) + sizeof(u32) + sizeof(u32))
+
+struct tpm_req_header {
+    TPM_REQ_HEADER;
+} PACKED;
+
+
+struct tpm_rsp_header {
+    TPM_RSP_HEADER;
+} PACKED;
+
+
+struct tpm_req_extend {
+    TPM_REQ_HEADER
+    u32    pcrindex;
+    u8     digest[SHA1_BUFSIZE];
+} PACKED;
+
+
+struct tpm_rsp_extend {
+    TPM_RSP_HEADER
+    u8     digest[SHA1_BUFSIZE];
+} PACKED;
+
+
+struct tpm_req_getcap_perm_flags {
+    TPM_REQ_HEADER
+    u32    capArea;
+    u32    subCapSize;
+    u32    subCap;
+} PACKED;
+
+
+struct tpm_permanent_flags {
+    u16    tag;
+    u8     flags[20];
+} PACKED;
+
+
+enum permFlagsIndex {
+    PERM_FLAG_IDX_DISABLE = 0,
+    PERM_FLAG_IDX_OWNERSHIP,
+    PERM_FLAG_IDX_DEACTIVATED,
+    PERM_FLAG_IDX_READPUBEK,
+    PERM_FLAG_IDX_DISABLEOWNERCLEAR,
+    PERM_FLAG_IDX_ALLOW_MAINTENANCE,
+    PERM_FLAG_IDX_PHYSICAL_PRESENCE_LIFETIME_LOCK,
+    PERM_FLAG_IDX_PHYSICAL_PRESENCE_HW_ENABLE,
+};
+
+
+struct tpm_res_getcap_perm_flags {
+    TPM_RSP_HEADER
+    u32    size;
+    struct tpm_permanent_flags perm_flags;
+} PACKED;
+
+
+struct tpm_res_getcap_ownerauth {
+    TPM_RSP_HEADER
+    u32    size;
+    u8     flag;
+} PACKED;
+
+
+struct tpm_res_sha1start {
+    TPM_RSP_HEADER
+    u32    max_num_bytes;
+} PACKED;
+
+
+struct tpm_res_sha1complete {
+    TPM_RSP_HEADER
+    u8     hash[20];
+} PACKED;
+
+struct pttti_extend {
+    struct pttti pttti;
+    struct tpm_req_extend req;
+} PACKED;
+
+
+struct pttto_extend {
+    struct pttto pttto;
+    struct tpm_rsp_extend rsp;
+} PACKED;
+
+
+enum ipltype {
+    IPL_BCV = 0,
+    IPL_EL_TORITO_1,
+    IPL_EL_TORITO_2
+};
+
+#if CONFIG_TCGBIOS
+void tcpa_acpi_init(void);
+int has_working_tpm(void);
+u32 tcpa_startup(void);
+u32 tcpa_leave_bios(void);
+u32 tcpa_s3_resume(void);
+#else
+static inline void tcpa_acpi_init(void) {
+}
+static inline int has_working_tpm(void) {
+    return 0;
+}
+static inline u32 tcpa_startup(void) {
+    return 0;
+}
+static inline u32 tcpa_leave_bios(void) {
+    return 0;
+}
+static inline u32 tcpa_s3_resume(void) {
+    return 0;
+}
+#endif
+void tcpa_menu(void);
+
+#endif /* TCGBIOS_H */
Index: seabios/src/util.c
===================================================================
--- seabios.orig/src/util.c
+++ seabios/src/util.c
@@ -322,3 +322,21 @@  get_keystroke(int msec)
         wait_irq();
     }
 }
+
+
+// wait a given time
+// this function also works in case of a resume
+void
+mssleep(u32 msec)
+{
+    u32 i;
+    u8 x, y = inb(0x61) & 0x10;
+
+    /* Poll the DRAM refresh timer: I/O port 61h, bit 4 toggles every 15us. */
+    msec *= (1000/15); /* Convert milliseconds to multiples of 15us. */
+    for ( i = 0; i < msec; i++ ) {
+        while ( (x = inb(0x61) & 0x10) == y )
+            continue;
+        y = x;
+    }
+}
Index: seabios/src/util.h
===================================================================
--- seabios.orig/src/util.h
+++ seabios/src/util.h
@@ -497,4 +497,9 @@  extern u8 BiosChecksum;
 // version (auto generated file out/version.c)
 extern const char VERSION[];
 
+
+void mssleep(u32 time);
+
+void tcpa_interrupt_handler16(struct bregs *regs);
+
 #endif // util.h
Index: seabios/src/post.c
===================================================================
--- seabios.orig/src/post.c
+++ seabios/src/post.c
@@ -25,6 +25,7 @@ 
 #include "paravirt.h" // qemu_cfg_port_probe
 #include "ps2port.h" // ps2port_setup
 #include "virtio-blk.h" // virtio_blk_setup
+#include "tcgbios.h" // tcpa_*
 
 
 /****************************************************************
@@ -238,6 +239,10 @@  maininit(void)
     mouse_setup();
     init_bios_tables();
 
+    // Initialize tpm (after acpi tables were written)
+    tcpa_acpi_init();
+    tcpa_startup();
+
     // Run vga option rom
     vga_setup();
 
Index: seabios/src/boot.c
===================================================================
--- seabios.orig/src/boot.c
+++ seabios/src/boot.c
@@ -14,6 +14,7 @@ 
 #include "cmos.h" // inb_cmos
 #include "paravirt.h" // romfile_loadfile
 #include "pci.h" //pci_bdf_to_*
+#include "tcgbios.h" // tcpa_*
 
 
 /****************************************************************
@@ -449,6 +450,7 @@  boot_prep(void)
     // Allow user to modify BCV/IPL order.
     interactive_bootmenu();
     wait_threads();
+    tcpa_leave_bios();
 
     // Map drives and populate BEV list
     struct bootentry_s *pos = BootList;
Index: seabios/src/resume.c
===================================================================
--- seabios.orig/src/resume.c
+++ seabios/src/resume.c
@@ -10,6 +10,7 @@ 
 #include "biosvar.h" // struct bios_data_area_s
 #include "bregs.h" // struct bregs
 #include "acpi.h" // find_resume_vector
+#include "tcgbios.h" // tcpa_s3_resume
 
 // Reset DMA controller
 void
@@ -116,6 +117,7 @@  s3_resume(void)
     if (s3_resume_vector) {
         dprintf(1, "Jump to resume vector (%x)\n", s3_resume_vector);
         br.code = FLATPTR_TO_SEGOFF((void*)s3_resume_vector);
+        tcpa_s3_resume();
     } else {
         dprintf(1, "No resume vector set!\n");
         // Jump to the post vector to restart with a normal boot.