1 files changed, 131 insertions, 0 deletions
diff --git a/src/runtime/export_debug_ppc64le_test.go b/src/runtime/export_debug_ppc64le_test.go
new file mode 100644
index 0000000..dd5dce5
--- /dev/null
+++ b/src/runtime/export_debug_ppc64le_test.go
@@ -0,0 +1,131 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ppc64le && linux
+
+package runtime
+
+import (
+	"internal/abi"
+	"internal/goarch"
+	"math"
+	"unsafe"
+)
+
+type sigContext struct {
+	savedRegs sigcontext
+}
+
+func sigctxtSetContextRegister(ctxt *sigctxt, x uint64) {
+	ctxt.regs().gpr[11] = x
+}
+
+func sigctxtAtTrapInstruction(ctxt *sigctxt) bool {
+	return *(*uint32)(unsafe.Pointer(ctxt.sigpc())) == 0x7fe00008 // Trap
+}
+
+func sigctxtStatus(ctxt *sigctxt) uint64 {
+	return ctxt.r20()
+}
+
+func (h *debugCallHandler) saveSigContext(ctxt *sigctxt) {
+	sp := ctxt.sp()
+	sp -= 4 * goarch.PtrSize
+	ctxt.set_sp(sp)
+	*(*uint64)(unsafe.Pointer(uintptr(sp))) = ctxt.link() // save the current lr
+	ctxt.set_link(ctxt.pc())                              // set new lr to the current pc
+	// Write the argument frame size.
+	*(*uintptr)(unsafe.Pointer(uintptr(sp - 32))) = h.argSize
+	// Save current registers.
+	h.sigCtxt.savedRegs = *ctxt.cregs()
+}
+
+// case 0
+func (h *debugCallHandler) debugCallRun(ctxt *sigctxt) {
+	sp := ctxt.sp()
+	memmove(unsafe.Pointer(uintptr(sp)+32), h.argp, h.argSize)
+	if h.regArgs != nil {
+		storeRegArgs(ctxt.cregs(), h.regArgs)
+	}
+	// Push return PC, which should be the signal PC+4, because
+	// the signal PC is the PC of the trap instruction itself.
+	ctxt.set_link(ctxt.pc() + 4)
+	// Set PC to call and context register.
+	ctxt.set_pc(uint64(h.fv.fn))
+	sigctxtSetContextRegister(ctxt, uint64(uintptr(unsafe.Pointer(h.fv))))
+}
+
+// case 1
+func (h *debugCallHandler) debugCallReturn(ctxt *sigctxt) {
+	sp := ctxt.sp()
+	memmove(h.argp, unsafe.Pointer(uintptr(sp)+32), h.argSize)
+	if h.regArgs != nil {
+		loadRegArgs(h.regArgs, ctxt.cregs())
+	}
+	// Restore the old lr from *sp
+	olr := *(*uint64)(unsafe.Pointer(uintptr(sp)))
+	ctxt.set_link(olr)
+	pc := ctxt.pc()
+	ctxt.set_pc(pc + 4) // step to next instruction
+}
+
+// case 2
+func (h *debugCallHandler) debugCallPanicOut(ctxt *sigctxt) {
+	sp := ctxt.sp()
+	memmove(unsafe.Pointer(&h.panic), unsafe.Pointer(uintptr(sp)+32), 2*goarch.PtrSize)
+	ctxt.set_pc(ctxt.pc() + 4)
+}
+
+// case 8
+func (h *debugCallHandler) debugCallUnsafe(ctxt *sigctxt) {
+	sp := ctxt.sp()
+	reason := *(*string)(unsafe.Pointer(uintptr(sp) + 40))
+	h.err = plainError(reason)
+	ctxt.set_pc(ctxt.pc() + 4)
+}
+
+// case 16
+func (h *debugCallHandler) restoreSigContext(ctxt *sigctxt) {
+	// Restore all registers except for pc and sp
+	pc, sp := ctxt.pc(), ctxt.sp()
+	*ctxt.cregs() = h.sigCtxt.savedRegs
+	ctxt.set_pc(pc + 4)
+	ctxt.set_sp(sp)
+}
+
+// storeRegArgs sets up argument registers in the signal
+// context state from an abi.RegArgs.
+//
+// Both src and dst must be non-nil.
+func storeRegArgs(dst *sigcontext, src *abi.RegArgs) {
+	// Gprs R3..R10, R14..R17 are used to pass int arguments in registers on PPC64
+	for i := 0; i < 12; i++ {
+		if i > 7 {
+			dst.gp_regs[i+6] = uint64(src.Ints[i])
+		} else {
+			dst.gp_regs[i+3] = uint64(src.Ints[i])
+		}
+	}
+	// Fprs F1..F13 are used to pass float arguments in registers on PPC64
+	for i := 0; i < 12; i++ {
+		dst.fp_regs[i+1] = math.Float64frombits(src.Floats[i])
+	}
+
+}
+
+func loadRegArgs(dst *abi.RegArgs, src *sigcontext) {
+	// Gprs R3..R10, R14..R17 are used to pass int arguments in registers on PPC64
+	for i := range [12]int{} {
+		if i > 7 {
+			dst.Ints[i] = uintptr(src.gp_regs[i+6])
+		} else {
+			dst.Ints[i] = uintptr(src.gp_regs[i+3])
+		}
+	}
+	// Fprs F1..F13 are used to pass float arguments in registers on PPC64
+	for i := range [12]int{} {
+		dst.Floats[i] = math.Float64bits(src.fp_regs[i+1])
+	}
+
+}