reactos/lib/sdk/crt/except/amd64/chkstk_ms.s
Amine Khaldi 527f2f9057 [SHELL/EXPERIMENTS]
* Create a branch for some evul shell experiments.

svn path=/branches/shell-experiments/; revision=61927
2014-02-02 19:37:27 +00:00

51 lines
1.3 KiB
ArmAsm

/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS system libraries
* PURPOSE: Implementation of _chkstk and _alloca_probe
* PROGRAMMERS Richard Henderson <rth@redhat.com>
* Kai Tietz <kai.tietz@onevision.com>
* Timo Kreuzer (timo.kreuzer@reactos.org)
*/
/* INCLUDES ******************************************************************/
#include <asm.inc>
#define PAGE_SIZE 4096
/* CODE **********************************************************************/
.code64
PUBLIC ___chkstk_ms
//cfi_startproc()
___chkstk_ms:
push rcx /* save temps */
//cfi_push(%rcx)
push rax
//cfi_push(%rax)
cmp rax, PAGE_SIZE /* > 4k ?*/
lea rcx, [rsp + 24] /* point past return addr */
jb l_LessThanAPage
l_MoreThanAPage:
sub rcx, PAGE_SIZE /* yes, move pointer down 4k */
or byte ptr [rcx], 0 /* probe there */
sub rax, PAGE_SIZE /* decrement count */
cmp rax, PAGE_SIZE
ja l_MoreThanAPage /* and do it again */
l_LessThanAPage:
sub rcx, rax
or byte ptr [rcx], 0 /* less than 4k, just peek here */
pop rax
//cfi_pop(%rax)
pop rcx
//cfi_pop(%rcx)
ret
//cfi_endproc()
END
/* EOF */