[PATCH] Allow to run option roms with bad checksums

[Stefan Reinauer]

See patch

[Kevin O'Connor]

On Fri, Feb 11, 2011 at 01:26:43PM -0800, Stefan Reinauer wrote:
> See patch
> Allow running option roms with a wrong checksum.
>
> Signed-off-by: Stefan Reinauer

This is an area where SeaBIOS could really use a mechanism to load
config settings dynamically (eg, from CBFS).  Having to recompile
SeaBIOS to set a flag like this is a pain.

Of course, in the interim, the patch looks okay to me.

-Kevin

[Kevin O'Connor]

On Fri, Feb 11, 2011 at 01:26:43PM -0800, Stefan Reinauer wrote:
> See patch
> Allow running option roms with a wrong checksum.
>
> Signed-off-by: Stefan Reinauer

Thanks.  I changed the name of the option and then committed this
patch.

-Kevin
> From cc975646af69f279396d4d5e1379ac6af80ee637 Mon Sep 17 00:00:00 2001

Message-Id: 
From: Kevin O'Connor 
Date: Sun, 6 Mar 2011 19:22:46 -0500
Subject: [PATCH] Add config option to permit running option roms with bad checksums.
To: [e-mail]

Based on a patch by: Stefan Reinauer 
---
 src/Kconfig      |   11 +++++++++++
 src/optionroms.c |    3 ++-
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/src/Kconfig b/src/Kconfig
index f064b27..6d55b23 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -250,6 +250,17 @@ menu "BIOS interfaces"
             Select this if option ROMs are already copied to
             0xc0000-0xf0000.  This must only be selected when using
             Bochs or QEMU versions older than 0.12.
+    config OPTIONROMS_CHECKSUM
+        depends on OPTIONROMS
+        bool "Require correct checksum on option ROMs"
+        default y
+        help
+            Option ROMs are required to have correct checksums.
+            However, some option ROMs in the wild don't correctly
+            follow the specifications and have bad checksums.
+            Say N here to allow SeaBIOS to execute them anyways.
+
+            If unsure, say Y.
     config PMM
         depends on OPTIONROMS
         bool "PMM interface"
diff --git a/src/optionroms.c b/src/optionroms.c
index a94b46c..37a4e6c 100644
--- a/src/optionroms.c
+++ b/src/optionroms.c
@@ -131,7 +131,8 @@ is_valid_rom(struct rom_header *rom)
     if (sum != 0) {
         dprintf(1, "Found option rom with bad checksum: loc=%p len=%d sum=%x\n"
                 , rom, len, sum);
-        return 0;
+        if (CONFIG_OPTIONROMS_CHECKSUM)
+            return 0;
     }
     return 1;
 }