linux/arch/i386/boot/voyager.c
H. Peter Anvin 5593eaa854 [x86 setup] Fix assembly constraints
Fix incorrect assembly constraints.  In particular, fix memory
constraints used inside push..pop, which can cause invalid operation
since gcc may generate %esp-relative references.

Additionally:

outl() should have "dN" not "dn".

query_mca() shouldn't listen 16/32-bit registers in an 8-bit only
context.

has_eflag(): the "mask" is only used well after both the stack pointer
and the output registers have been touched; this requires the output
registers to be earlyclobbers (=&) and the input to exclude memory (so
"ri", not "g").

Thanks to Etienne Lorrain and Chuck Ebbert for prompting this review.

Cc: Etienne Lorrain <etienne_lorrain@yahoo.fr>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2007-07-18 11:36:17 -07:00

47 lines
1.0 KiB
C

/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* ----------------------------------------------------------------------- */
/*
* arch/i386/boot/voyager.c
*
* Get the Voyager config information
*/
#include "boot.h"
#ifdef CONFIG_X86_VOYAGER
int query_voyager(void)
{
u8 err;
u16 es, di;
/* Abuse the apm_bios_info area for this */
u8 *data_ptr = (u8 *)&boot_params.apm_bios_info;
data_ptr[0] = 0xff; /* Flag on config not found(?) */
asm("pushw %%es ; "
"int $0x15 ; "
"setc %0 ; "
"movw %%es, %1 ; "
"popw %%es"
: "=q" (err), "=r" (es), "=D" (di)
: "a" (0xffc0));
if (err)
return -1; /* Not Voyager */
set_fs(es);
copy_from_fs(data_ptr, di, 7); /* Table is 7 bytes apparently */
return 0;
}
#endif /* CONFIG_X86_VOYAGER */