diff options
| author | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 22:22:37 +0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 22:48:03 +0400 |
| commit | e5684ec438a094bec0f7d5c52652c0901b48b613 (patch) | |
| tree | 8cc3cf787a582977ff08ed578907d6df7dbc7e6e /arch/x86/realmode/rm/trampoline_32.S | |
| parent | 968ff9ee56f1e3ed4ff4a6d10185865dc77d8f7e (diff) | |
| download | linux-e5684ec438a094bec0f7d5c52652c0901b48b613.tar.xz | |
x86, realmode: Replace open-coded ljmpw with a macro
We cannot code an ljmpw to the real-mode segment directly, because gas
refuses to assemble an ljmp with a symbolic segment. Instead of
open-coding it everywhere, define a macro and use it for this case.
This is specifically an ljmpw from a 16-bit segment. This is okay, as
one should never enter real mode from a 32-bit segment: if one do, the
CPU ends up in a bizarre (and useless) mode sometimes called "unreal
mode" where segments behave like real mode but the default address and
operand sizes is 32 bits.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-15-git-send-email-jarkko.sakkinen@intel.com
Diffstat (limited to 'arch/x86/realmode/rm/trampoline_32.S')
| -rw-r--r-- | arch/x86/realmode/rm/trampoline_32.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S index 1315ef48dbf1..279f82ef7a9e 100644 --- a/arch/x86/realmode/rm/trampoline_32.S +++ b/arch/x86/realmode/rm/trampoline_32.S @@ -29,6 +29,7 @@ #include <linux/init.h> #include <asm/segment.h> #include <asm/page_types.h> +#include "realmode.h" .text .code16 @@ -38,9 +39,7 @@ trampoline_data: wbinvd # Needed for NUMA-Q should be harmless for others - .byte 0xea # ljmpw - .word 1f # Offset - .word real_mode_seg # Segment + LJMPW_RM(1f) 1: mov %cs, %ax # Code and data in the same place mov %ax, %ds |