aboutsummaryrefslogtreecommitdiff
path: root/src/runtime/rt0_amd64.s
diff options
context:
space:
mode:
Diffstat (limited to 'src/runtime/rt0_amd64.s')
-rw-r--r--src/runtime/rt0_amd64.s19
1 files changed, 19 insertions, 0 deletions
diff --git a/src/runtime/rt0_amd64.s b/src/runtime/rt0_amd64.s
index d6dba02864..71b1fd8f30 100644
--- a/src/runtime/rt0_amd64.s
+++ b/src/runtime/rt0_amd64.s
@@ -72,6 +72,25 @@ TEXT gosave(SB), 7, $0
MOVL $0, AX // return 0
RET
+/*
+ * support for morestack
+ */
+
+// return point when leaving new stack. save AX, jmp to oldstack to switch back
+TEXT retfromnewstack(SB), 7, $0
+ MOVQ AX, 16(R14) // save AX in m->cret
+ MOVQ $oldstack(SB), AX
+ JMP AX
+
+// gogo, returning 2nd arg instead of 1
+TEXT gogoret(SB), 7, $0
+ MOVQ 16(SP), AX // return 2nd arg
+ MOVQ 8(SP), BX // gobuf
+ MOVQ 0(BX), SP // restore SP
+ MOVQ 8(BX), BX
+ MOVQ BX, 0(SP) // put PC on the stack
+ RET
+
TEXT setspgoto(SB), 7, $0
MOVQ 8(SP), AX // SP
MOVQ 16(SP), BX // fn to call