From ff56954baf9cfab5cbbe18d10b4a09e4a17f39a8 Mon Sep 17 00:00:00 2001
From: Juergen Lock <nox@jelal.kn-bremen.de>
Date: Tue, 13 Oct 2009 23:29:12 +0200
Subject: [PATCH] multiboot.S patch for old as(1) (was: Re: [Qemu-devel] Some
OpenBSD/amd64 build fixes)
On Wed, Sep 23, 2009 at 10:55:02PM +0200, Juergen Lock wrote:
> On Wed, Sep 23, 2009 at 09:31:16PM +0100, Laurence Tratt wrote:
>[...]
> > then the above error doesn't occur, but
> > pc-bios/optionrom/multiboot.S dies as follows:
> >
> > $
> > AS optionrom/multiboot.o
> > multiboot.S: Assembler messages:
> > multiboot.S:116: Error: `%es:-4(%edi)' is not a valid 16 bit base/index
> > expression
> > $
> >
> > What little Intel assembler I ever knew has long since departed from my
> > brain, so I don't know why that error occurs, nor what a fix might be.
> >
> It occurs because of too old binutils (as(1) in this case), on FreeBSD
> we now have a port for newer ones,
> http://www.freshports.org/devel/binutils
> so I depend on that and have the optionrom Makefile use the new as
> like this: (the first change wrt CFLAGS is unrelated and has probably
> been fixed in the meantime; it caused gmake to complain about
> recursive use of CFLAGS.)
>
> Index: qemu/pc-bios/optionrom/Makefile
> @@ -9,10 +9,13 @@
>
> CFLAGS = -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin
> CFLAGS += -I$(SRC_PATH)
> -CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector,"")
> +CFLAGS := $(CFLAGS) $(call cc-option, $(CFLAGS), -fno-stack-protector,"")
>
> build-all: multiboot.bin
>
> +%.o: %.S
> + $(CC) -E $(CFLAGS) -o - -c $< |${LOCALBASE}/bin/as -V -Qy -o $@
> +
> %.img: %.o
> $(call quiet-command,$(LD) -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@")
>
That patch didn't seem to help on OpenBSD so I now finally got around
making another one that just emits the bytes of the offending insn
instead so people can keep using old assemblers:
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
pc-bios/optionrom/multiboot.S | 3 +++
1 file changed, 3 insertions(+)
diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
index 93beb51b63..e6cbefdc92 100644
--- a/pc-bios/optionrom/multiboot.S
+++ b/pc-bios/optionrom/multiboot.S
@@ -113,7 +113,10 @@ mmap_loop:
/* entry size (mmap struct) & max buffer size (int15) */
movl $20, %ecx
/* store entry size */
+ /* old as(1) doesn't like this insn so emit the bytes instead:
movl %ecx, %es:-4(%edi)
+ */
+ .dc.b 0x26,0x67,0x66,0x89,0x4f,0xfc
/* e820 */
movl $0x0000e820, %eax
/* 'SMAP' magic */