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2009-06-04 Vladimir Serbinenko <phcoder@gmail.com>

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Avoid clobbering %ebx/%rbx in inline assembly with Apple's CC

	* efiemu/runtime/efiemu.c (write_cmos): use %cl instead of %bl as
	temporary storage
	* include/grub/i386/tsc.h (grub_get_tsc): restore %rbx/%ebx when 
	using Apple's CC 
	(grub_cpu_is_tsc_supported): likewise
	* loader/i386/xnu.c (guessfsb): restore %rbx/%ebx in inline assembly
This commit is contained in:
phcoder 2009-06-04 20:10:51 +00:00
parent 3e32590112
commit cc6c3ac1bf
4 changed files with 90 additions and 5 deletions
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38
include/grub/i386/tsc.h
View file

@ -29,8 +29,24 @@ grub_get_tsc (void)
/* The CPUID instruction is a 'serializing' instruction, and
avoids out-of-order execution of the RDTSC instruction. */
#ifdef APPLE_CC
__asm__ __volatile__ ("xorl %%eax, %%eax\n\t"
"cpuid":::"%rax", "%rbx", "%rcx", "%rdx");
#ifdef __x86_64__
"push %%rbx\n"
#else
"push %%ebx\n"
#endif
"cpuid\n"
#ifdef __x86_64__
"pop %%rbx\n"
#else
"pop %%ebx\n"
#endif
:::"%rax", "%rcx", "%rdx");
#else
__asm__ __volatile__ ("xorl %%eax, %%eax\n\t"
"cpuid":::"%rax", "%rbx", "%rcx", "%rdx");
#endif
/* Read TSC value. We cannot use "=A", since this would use
%rax on x86_64. */
__asm__ __volatile__ ("rdtsc":"=a" (lo), "=d" (hi));
@ -93,11 +109,29 @@ grub_cpu_is_tsc_supported (void)
return 0;
grub_uint32_t features;
#ifdef APPLE_CC
__asm__ ("movl $1, %%eax\n\t"
"cpuid"
#ifdef __x86_64__
"push %%rbx\n"
#else
"push %%ebx\n"
#endif
"cpuid\n"
#ifdef __x86_64__
"pop %%rbx\n"
#else
"pop %%ebx\n"
#endif
: "=d" (features)
: /* No inputs. */
: /* Clobbered: */ "%rax", "%rcx");
#else
__asm__ ("movl $1, %%eax\n\t"
"cpuid\n"
: "=d" (features)
: /* No inputs. */
: /* Clobbered: */ "%rax", "%rbx", "%rcx");
#endif
return (features & (1 << 4)) != 0;
}