diff options
Diffstat (limited to 'usr/klibc/arch/parisc/vfork.S')
-rw-r--r-- | usr/klibc/arch/parisc/vfork.S | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/usr/klibc/arch/parisc/vfork.S b/usr/klibc/arch/parisc/vfork.S new file mode 100644 index 0000000..3868a8d --- /dev/null +++ b/usr/klibc/arch/parisc/vfork.S @@ -0,0 +1,32 @@ +/* + * arch/parisc/vfork.S, "vfork() me harder. ugh." -- kyle + * + * %rp contains whence we came, + * %rp is saved and restored across the syscall, thankfully. + * + */ + + .text + .align 64 ; cache-width aligned + .globl vfork + .type vfork,@function +vfork: + /* pid_t vfork(void) */ + ldi 113,%r20 + ble 0x100(%sr2, %r0) ; jump to gateway page + nop + + ldi -0x1000,%r19 ; %r19 = -4096 + sub %r0,%ret0,%r22 ; %r22 = -%ret0 + cmpb,>>=,n %r19,%ret0,1f ; if %ret0 >= -4096UL + ldi -1,%ret0 ; nullified on taken forward + + /* store %r22 to errno... */ + ldil L%errno,%r1 + ldo R%errno(%r1),%r1 + stw %r22,0(%r1) +1: + bv %r0(%rp) ; jump back + nop + + .size vfork,.-vfork |