minix/lib/sysutil/read_tsc.s
Ben Gras 8c2bece89f - remove unused kmalloc
- initial implementation of _read_host_time_ns, a function to retrieve
   real-time in ns in vmware virtual machines
2009-09-21 14:39:15 +00:00

49 lines
1 KiB
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
!*===========================================================================*
! PUBLIC void read_host_time_ns(unsigned long *high, unsigned long *low);
! access real time in ns from host in vmware.
.align 16
_read_host_time_ns:
push edx
push eax
push ecx
mov ecx, 0x10001
.data1 0x0f ! this is the RDPMC instruction
.data1 0x33 ! it places the result in EDX:EAX
push ebp
mov ebp, 20(esp)
mov (ebp), edx
mov ebp, 24(esp)
mov (ebp), eax
pop ebp
pop ecx
pop eax
pop edx
ret