C CPUID interface.

diff --git a/lib/i386/misc/Makefile.in b/lib/i386/misc/Makefile.in
index 511524f088214caa878600c1e34c35b7126d3842..3b139e97e501b377f166d4a4101db8796a2ba9cd 100644 (file)
--- a/lib/i386/misc/Makefile.in
+++ b/lib/i386/misc/Makefile.in
@@ -5,6 +5,7 @@ CFLAGS="-O -D_MINIX -D_POSIX_SOURCE"
 LIBRARIES=libc
 
 libc_FILES=" \
+       _cpuid.s \
        alloca.s \
        get_bp.s \
        getprocessor.s \

diff --git a/lib/i386/misc/_cpuid.s b/lib/i386/misc/_cpuid.s
new file mode 100755 (executable)
index 0000000..6ca569a
--- /dev/null
+++ b/lib/i386/misc/_cpuid.s
@@ -0,0 +1,44 @@
+! _cpuid() - interface to cpuid instruction
+
+.sect .text; .sect .rom; .sect .data; .sect .bss
+.sect .text
+
+! int _cpuid(u32_t eax, u32_t *eax, u32_t *ebx, u32_t *ecx, u32_t *edx);
+! 0 for OK, nonzero for unsupported
+
+.define        __cpuid
+
+__cpuid:
+       push    ebp
+
+       mov     ebp, esp
+
+       ! save work registers
+       push    eax
+       push    ebx
+       push    ecx
+       push    edx
+
+       ! set eax parameter to cpuid and execute cpuid
+       mov     eax,  24(esp)
+       .data1  0x0F, 0xA2      ! CPUID
+
+       ! store results in pointer arguments
+       mov     ebp, 28(esp)
+       mov     (ebp), eax
+       mov     ebp, 32(esp)
+       mov     (ebp), ebx
+       mov     ebp, 36(esp)
+       mov     (ebp), ecx
+       mov     ebp, 40(esp)
+       mov     (ebp), edx
+
+       ! restore registers
+       pop     edx
+       pop     ecx
+       pop     ebx
+       pop     eax
+
+       pop     ebp
+
+       ret