[Qemu-devel] [RFC] check VGA BIOS size

[Qemu-devel] [RFC] check VGA BIOS size

[Bernhard Fischer]

[-- Attachment #1: Type: text/plain, Size: 328 bytes --]

Hi,

What do you think about checking if a VGA bios was found (and if so, if
it has a valid size)?

Reasoning is that on pristine machines (i.e. without a VGA bios ROM
available) starting qemu fails without giving any helpful error message.

I'm attaching a simple patch which adds such a check.

Comments?

Thank you,
Bernhard

[-- Attachment #2: qemu.hw_pc.c-check-vga-bios-size.diff --]
[-- Type: text/plain, Size: 983 bytes --]

diff -X excl -rduNp qemu.oorig/hw/pc.c qemu/hw/pc.c
--- qemu.oorig/hw/pc.c	2005-07-28 17:54:38.000000000 +0200
+++ qemu/hw/pc.c	2005-07-31 13:38:23.000000000 +0200
@@ -414,7 +414,7 @@ static void pc_init1(int ram_size, int v
     char buf[1024];
     int ret, linux_boot, initrd_size, i, nb_nics1;
     unsigned long bios_offset, vga_bios_offset;
-    int bios_size, isa_bios_size;
+    int bios_size, isa_bios_size, vga_bios_size;
     PCIBus *pci_bus;
 
     linux_boot = (kernel_filename != NULL);
@@ -446,8 +446,12 @@ static void pc_init1(int ram_size, int v
     } else {
         snprintf(buf, sizeof(buf), "%s/%s", bios_dir, VGABIOS_FILENAME);
     }
+    vga_bios_size = get_image_size(buf);
+    if (vga_bios_size != 32768)
+	    goto bios_error;
+
     ret = load_image(buf, phys_ram_base + vga_bios_offset);
-    
+
     /* setup basic memory access */
     cpu_register_physical_memory(0xc0000, 0x10000, 
                                  vga_bios_offset | IO_MEM_ROM);

Re: [Qemu-devel] [RFC] check VGA BIOS size

[Bernhard Fischer]

Fabrice,

Will you accept such a check?

kind regards,

On Sun, Jul 31, 2005 at 01:53:20PM +0200, Bernhard Fischer wrote:
>Hi,
>
>What do you think about checking if a VGA bios was found (and if so, if
>it has a valid size)?
>
>Reasoning is that on pristine machines (i.e. without a VGA bios ROM
>available) starting qemu fails without giving any helpful error message.
>
>I'm attaching a simple patch which adds such a check.
>
>Comments?
>
>Thank you,
>Bernhard

>diff -X excl -rduNp qemu.oorig/hw/pc.c qemu/hw/pc.c
>--- qemu.oorig/hw/pc.c	2005-07-28 17:54:38.000000000 +0200
>+++ qemu/hw/pc.c	2005-07-31 13:38:23.000000000 +0200
>@@ -414,7 +414,7 @@ static void pc_init1(int ram_size, int v
>     char buf[1024];
>     int ret, linux_boot, initrd_size, i, nb_nics1;
>     unsigned long bios_offset, vga_bios_offset;
>-    int bios_size, isa_bios_size;
>+    int bios_size, isa_bios_size, vga_bios_size;
>     PCIBus *pci_bus;
> 
>     linux_boot = (kernel_filename != NULL);
>@@ -446,8 +446,12 @@ static void pc_init1(int ram_size, int v
>     } else {
>         snprintf(buf, sizeof(buf), "%s/%s", bios_dir, VGABIOS_FILENAME);
>     }
>+    vga_bios_size = get_image_size(buf);
>+    if (vga_bios_size != 32768)
>+	    goto bios_error;
>+
>     ret = load_image(buf, phys_ram_base + vga_bios_offset);
>-    
>+
>     /* setup basic memory access */
>     cpu_register_physical_memory(0xc0000, 0x10000, 
>                                  vga_bios_offset | IO_MEM_ROM);
>

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