2007-01-29 13:46:44

by Rene Herman

[permalink] [raw]
Subject: [PATCH] x86_64: sync up probe_roms() with i386

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index af425a8..0b3d237 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -183,22 +183,31 @@ static struct resource video_ram_resourc
.flags = IORESOURCE_RAM,
};

-#define romsignature(x) (*(unsigned short *)(x) == 0xaa55)
+#define ROMSIGNATURE 0xaa55

-static int __init romchecksum(unsigned char *rom, unsigned long length)
+static int __init romsignature(const unsigned char *rom)
{
- unsigned char *p, sum = 0;
+ const unsigned short * const ptr = (const unsigned short *)rom;
+ unsigned short sig;

- for (p = rom; p < rom + length; p++)
- sum += *p;
- return sum == 0;
+ return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE;
+}
+
+static int __init romchecksum(const unsigned char *rom, unsigned long length)
+{
+ unsigned char sum, c;
+
+ for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--)
+ sum += c;
+ return !length && !sum;
}

static void __init probe_roms(void)
{
+ const unsigned char *rom;
unsigned long start, length, upper;
- unsigned char *rom;
- int i;
+ unsigned char c;
+ int i;

/* video rom */
upper = adapter_rom_resources[0].start;
@@ -209,8 +218,11 @@ static void __init probe_roms(void)

video_rom_resource.start = start;

+ if (probe_kernel_address(rom, c) != 0)
+ continue;
+
/* 0 < length <= 0x7f * 512, historically */
- length = rom[2] * 512;
+ length = c * 512;

/* if checksum okay, trust length byte */
if (length && romchecksum(rom, length))
@@ -245,8 +257,11 @@ static void __init probe_roms(void)
if (!romsignature(rom))
continue;

+ if (probe_kernel_address(rom, c) != 0)
+ continue;
+
/* 0 < length <= 0x7f * 512, historically */
- length = rom[2] * 512;
+ length = c * 512;

/* but accept any length that fits if checksum okay */
if (!length || start + length > upper || !romchecksum(rom, length))


Attachments:
x86_64_sync_probe_roms_with_i386.diff (1.89 kB)

2007-01-29 16:55:49

by Rene Herman

[permalink] [raw]
Subject: Re: [PATCH] x86_64: sync up probe_roms() with i386

On 01/29/2007 02:46 PM, Rene Herman wrote:

> This syncs up the x86_64 probe_roms() with the i386 version as just
> submitted.
>
> ===
> Sync up with i386. Specifically, be careful about touching the
> legacy ROMs; in virtualized environments they may not be mapped.
>
> Crosscompiled, but not booted due to lack of hardware.
>
> Signed-off-by: Rene Herman <[email protected]>
> ===

In the meantime tested by Martin Murray on x86_64 native and inside
vmware (thanks much!) who told me I could add his sob:

Signed-off-by: Martin Murray <[email protected]>

Rene.