878ba523ac
This library includes various random and minix-specific functions included in the Minix libc. Most of them should be part of libsys, and in general it would be nice to extinguish this library over time.
52 lines
1.4 KiB
ArmAsm
52 lines
1.4 KiB
ArmAsm
/* getprocessor() - determine processor type Author: Kees J. Bot */
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/* 26 Jan 1994 */
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#include <machine/asm.h>
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/* int getprocessor(void); */
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/* Return 386, 486, 586, ... */
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ENTRY(getprocessor)
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push %ebp
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movl %esp, %ebp
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andl $0xFFFFFFFC, %esp /* Align stack to avoid AC fault */
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movl $0x00040000, %ecx /* Try to flip the AC bit introduced on the 486 */
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call flip
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movl $386, %eax /* 386 if it didn't react to "flipping" */
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je gotprocessor
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movl $0x00200000, %ecx /* Try to flip the ID bit introduced on the 586 */
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call flip
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movl $486, %eax /* 486 if it didn't react */
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je gotprocessor
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pushf
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pusha /* Save the world */
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movl $1, %eax
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.byte 0x0F, 0xA2 /* CPUID instruction tells the processor type */
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andb $0x0F, %ah /* Extract the family (5, 6, ...) */
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movzbl %ah, %eax
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cmpl $15, %eax /* 15: extended family */
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jne direct
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movl $6, %eax /* Make it 686 */
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direct:
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imull $100, %eax /* 500, 600, ... */
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addl $86, %eax /* 586, 686, ... */
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movl %eax, 7*4(%esp) /* Pass eax through */
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popa
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popf
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gotprocessor:
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leave
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ret
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flip:
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pushf /* Push eflags */
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pop %eax /* eax = eflags */
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movl %eax, %edx /* Save original eflags */
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xorl %ecx, %eax /* Flip the bit to test */
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push %eax /* Push modified eflags value */
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popf /* Load modified eflags register */
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pushf
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pop %eax /* Get it again */
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push %edx
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popf /* Restore original eflags register */
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xorl %edx, %eax /* See if the bit changed */
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testl %ecx, %eax
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ret
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