From: "H. Peter Anvin" <hpa@zytor.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] Motivation of BIOS patch?
Date: Wed, 16 Jan 2008 22:18:52 -0500 [thread overview]
Message-ID: <478EC91C.1030601@zytor.com> (raw)
I saw the following patch in the Qemu source:
Index: rombios.c
===================================================================
RCS file: /cvsroot/bochs/bochs/bios/rombios.c,v
retrieving revision 1.174
diff -u -w -r1.174 rombios.c
--- rombios.c 17 Oct 2006 16:48:05 -0000 1.174
+++ rombios.c 8 Feb 2007 21:57:48 -0000
@@ -9472,6 +9472,14 @@
mov eax, #0x00040000
call eax
+ ;; reset the memory (some boot loaders such as syslinux suppose
+ ;; that the memory is set to zero)
+ mov edi, #0x00040000
+ mov ecx, #0x40000 / 4
+ xor eax, eax
+ rep
+ stosd
+
;; return to 16 bit protected mode first
db 0xea
dd rombios32_10
Being the SYSLINUX author I'm more than a little surprised about this;
this is probably indicative of a serious bug (possibly now fixed).
Anyone who has any information about this?
-hpa
reply other threads:[~2008-01-17 3:24 UTC|newest]
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