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-rw-r--r--usr/klibc/arch/parisc/vfork.S32
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