Patchwork [1/1] hw: better i440 emulation

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Submitter Bernhard M. Wiedemann
Date April 19, 2010, 3:47 p.m.
Message ID <20100419154719.GA8863@zq1.de>
Download mbox | patch
Permalink /patch/50490/
State New
Headers show

Comments

Bernhard M. Wiedemann - April 19, 2010, 3:47 p.m.
attached is a tested 0.12.3-version of an old patch
http://xenon.stanford.edu/~eswierk/misc/qemu-linuxbios/qemu-piix-ram-size.patch
that together with
http://www.mail-archive.com/linuxbios@linuxbios.org/msg02390.html
(which is already in coreboot trunk) allows coreboot BIOS to autodetect the amount of RAM within qemu/kvm from a register in i440 northbridge.

The message on the old patch states:
Unfortunately the current version of qemu does not set these
registers, but I have patched qemu so that it emulates the i440 more
faithfully in this regard.



new patch is also available at
http://www.zq1.de/~bernhard/linux/qemu-0.12.3-piix-ram-size.patch

Please discuss or apply this patch.

regards
Bernhard M. Wiedemann
--
software engineer
Andreas Färber - April 20, 2010, 4:55 p.m.
Am 19.04.2010 um 17:47 schrieb Bernhard M. Wiedemann:

> attached is a tested 0.12.3-version of an old patch
> http://xenon.stanford.edu/~eswierk/misc/qemu-linuxbios/qemu-piix-ram-size.patch
> that together with
> http://www.mail-archive.com/linuxbios@linuxbios.org/msg02390.html
> (which is already in coreboot trunk) allows coreboot BIOS to  
> autodetect the amount of RAM within qemu/kvm from a register in i440  
> northbridge.
>
> The message on the old patch states:
> Unfortunately the current version of qemu does not set these
> registers, but I have patched qemu so that it emulates the i440 more
> faithfully in this regard.

Both the original patch and yours are missing a Signed-off-by statement.
Generally preferred are patches against git master branch with a ready- 
to-commit summary, sent with git-send-email.

Andreas

Patch

diff -ru ./hw/pc.c ../qpatch/hw/pc.c
--- ./hw/pc.c	2010-02-26 03:34:00.000000000 +0100
+++ ../qpatch/hw/pc.c	2010-04-19 17:18:12.000000000 +0200
@@ -1130,7 +1130,7 @@ 
     }
 
     if (pci_enabled) {
-        pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, isa_irq);
+        pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, isa_irq, ram_size);
     } else {
         pci_bus = NULL;
         isa_bus_new(NULL);
diff -ru ./hw/pc.h ../qpatch/hw/pc.h
--- ./hw/pc.h	2010-02-26 03:34:00.000000000 +0100
+++ ../qpatch/hw/pc.h	2010-04-19 17:10:50.000000000 +0200
@@ -129,7 +129,7 @@ 
 struct PCII440FXState;
 typedef struct PCII440FXState PCII440FXState;
 
-PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn, qemu_irq *pic);
+PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix_devfn, qemu_irq *pic, int ram_size);
 void i440fx_set_smm(PCII440FXState *d, int val);
 void i440fx_init_memory_mappings(PCII440FXState *d);
 
diff -ru ./hw/piix_pci.c ../qpatch/hw/piix_pci.c
--- ./hw/piix_pci.c	2010-02-26 03:34:00.000000000 +0100
+++ ../qpatch/hw/piix_pci.c	2010-04-19 17:27:59.000000000 +0200
@@ -209,7 +209,7 @@ 
 
 static PIIX3State *piix3_dev;
 
-PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix3_devfn, qemu_irq *pic)
+PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix3_devfn, qemu_irq *pic, int ram_size)
 {
     DeviceState *dev;
     PCIBus *b;
@@ -236,6 +236,11 @@ 
 
     piix3_dev = piix3;
 
+    ram_size = ram_size / 8 / 1024 / 1024;
+    if (ram_size > 255)
+        ram_size = 255;
+    (*pi440fx_state)->dev.config[0x57]=ram_size;
+
     return b;
 }