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| author | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 21:22:37 +0300 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 11:48:03 -0700 |
| commit | e5684ec438a094bec0f7d5c52652c0901b48b613 (patch) | |
| tree | 8cc3cf787a582977ff08ed578907d6df7dbc7e6e /arch/x86/realmode/rm/wakeup | |
| parent | 968ff9ee56f1e3ed4ff4a6d10185865dc77d8f7e (diff) | |
| download | talos-op-linux-e5684ec438a094bec0f7d5c52652c0901b48b613.tar.gz talos-op-linux-e5684ec438a094bec0f7d5c52652c0901b48b613.zip | |
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/wakeup')
| -rw-r--r-- | arch/x86/realmode/rm/wakeup/wakeup_asm.S | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/x86/realmode/rm/wakeup/wakeup_asm.S b/arch/x86/realmode/rm/wakeup/wakeup_asm.S index 4c5c5f2bfbec..8064e1c3591b 100644 --- a/arch/x86/realmode/rm/wakeup/wakeup_asm.S +++ b/arch/x86/realmode/rm/wakeup/wakeup_asm.S @@ -6,6 +6,7 @@ #include <asm/page_types.h> #include <asm/pgtable_types.h> #include <asm/processor-flags.h> +#include "../realmode.h" #include "wakeup.h" .code16 @@ -36,9 +37,7 @@ wakeup_start: cli cld - .byte 0xea /* ljmpw */ - .word 3f - .word real_mode_seg + LJMPW_RM(3f) 3: /* Apparently some dimwit BIOS programmers don't know how to program a PM to RM transition, and we might end up here with @@ -59,9 +58,7 @@ wakeup_start: andb $~X86_CR0_PE, %al movl %eax, %cr0 - .byte 0xea /* ljmpw */ - .word 3f - .word real_mode_seg + LJMPW_RM(3f) 3: /* Set up segments */ movw %cs, %ax |
