minix/lib/sysutil/read_tsc.s
Ben Gras 6d50591226 . let kernel use read_tsc() from sysutil library
. read_tsc() in sysutil library saves edx and eax now
 . added read_tsc_64() by Antonio Mancina to load tsc into
   a 64-bit data type directly
 . deleted read_tsc.h in favour of a prototype in <minix/syslib.h>
2007-03-08 15:39:14 +00:00

27 lines
578 B
ArmAsm

#
! sections
.sect .text; .sect .rom; .sect .data; .sect .bss
.define _read_tsc ! read the cycle counter (Pentium and up)
.sect .text
!*===========================================================================*
! PUBLIC void read_tsc(unsigned long *high, unsigned long *low);
! Read the cycle counter of the CPU. Pentium and up.
.align 16
_read_tsc:
push edx
push eax
.data1 0x0f ! this is the RDTSC instruction
.data1 0x31 ! it places the TSC in EDX:EAX
push ebp
mov ebp, 16(esp)
mov (ebp), edx
mov ebp, 20(esp)
mov (ebp), eax
pop ebp
pop eax
pop edx
ret