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rtlib: fix some minor bugs in fb_CpuDetect for x86 #85

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Merged
merged 1 commit into from
May 26, 2018
Merged

rtlib: fix some minor bugs in fb_CpuDetect for x86 #85

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3 changes: 2 additions & 1 deletion src/rtlib/x86/cpudetect.s
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Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,7 @@ detect:
/* no CPUID; assume 386 and check if 486 (try toggling bit 18 (AC) of EFLAGS) */
mov ebx, 0x30000000
mov ecx, esp
and esp, 0xFFFFFFFB /* round ESP down to a multiple of 4 (must be aligned if AC becomes enabled) */
and esp, 0xFFFFFFFC /* round ESP down to a multiple of 4 (must be aligned if AC becomes enabled) */
pushfd
pop eax
mov edx, eax
Expand All @@ -71,6 +71,7 @@ cpu486_not_found:
cpuid_ok:
mov eax, 1
cpuid
mov al, 0
shl eax, 20
and edx, 0x0FFFFFFF /* low 28 bits of feature flags */
or eax, edx
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