forked from KolibriOS/kolibrios
37 lines
1.1 KiB
ArmAsm
37 lines
1.1 KiB
ArmAsm
|
|
||
|
|
.global ___chkstk
|
||
|
|
.global __alloca
|
||
|
|
|
||
|
|
.section .text
|
||
|
|
|
||
|
|
___chkstk:
|
||
|
|
__alloca:
|
||
|
|
pushl %ecx /* save temp */
|
||
|
|
leal 8(%esp), %ecx /* point past return addr */
|
||
|
|
cmpl $0x1000, %eax /* > 4k ?*/
|
||
|
|
jb Ldone
|
||
|
|
|
||
|
|
Lprobe:
|
||
|
|
subl $0x1000, %ecx /* yes, move pointer down 4k*/
|
||
|
|
orl $0x0, (%ecx) /* probe there */
|
||
|
|
subl $0x1000, %eax /* decrement count */
|
||
|
|
cmpl $0x1000, %eax
|
||
|
|
ja Lprobe /* and do it again */
|
||
|
|
|
||
|
|
Ldone:
|
||
|
|
subl %eax, %ecx
|
||
|
|
orl $0x0, (%ecx) /* less than 4k, just peek here */
|
||
|
|
|
||
|
|
movl %esp, %eax /* save old stack pointer */
|
||
|
|
movl %ecx, %esp /* decrement stack */
|
||
|
|
movl (%eax), %ecx /* recover saved temp */
|
||
|
|
movl 4(%eax), %eax /* recover return address */
|
||
|
|
|
||
|
|
/* Push the return value back. Doing this instead of just
|
||
|
|
jumping to %eax preserves the cached call-return stack
|
||
|
|
used by most modern processors. */
|
||
|
|
pushl %eax
|
||
|
|
ret
|
||
|
|
|
||
|
|
|