runtime: add support files for linux/mips{,le} port

Only exe buildmode without cgo supported.

Change-Id: Id104a79a99d3285c04db00fd98b8affa94ea3c37
Reviewed-on: https://go-review.googlesource.com/31487
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/src/runtime/signal_mipsx.go b/src/runtime/signal_mipsx.go
new file mode 100644
index 0000000000..62df79caeb
--- /dev/null
+++ b/src/runtime/signal_mipsx.go
@@ -0,0 +1,91 @@
+// Copyright 2016 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.
+
+// +build linux
+// +build mips mipsle
+
+package runtime
+
+import (
+	"runtime/internal/sys"
+	"unsafe"
+)
+
+func dumpregs(c *sigctxt) {
+	print("r0   ", hex(c.r0()), "\t")
+	print("r1   ", hex(c.r1()), "\n")
+	print("r2   ", hex(c.r2()), "\t")
+	print("r3   ", hex(c.r3()), "\n")
+	print("r4   ", hex(c.r4()), "\t")
+	print("r5   ", hex(c.r5()), "\n")
+	print("r6   ", hex(c.r6()), "\t")
+	print("r7   ", hex(c.r7()), "\n")
+	print("r8   ", hex(c.r8()), "\t")
+	print("r9   ", hex(c.r9()), "\n")
+	print("r10  ", hex(c.r10()), "\t")
+	print("r11  ", hex(c.r11()), "\n")
+	print("r12  ", hex(c.r12()), "\t")
+	print("r13  ", hex(c.r13()), "\n")
+	print("r14  ", hex(c.r14()), "\t")
+	print("r15  ", hex(c.r15()), "\n")
+	print("r16  ", hex(c.r16()), "\t")
+	print("r17  ", hex(c.r17()), "\n")
+	print("r18  ", hex(c.r18()), "\t")
+	print("r19  ", hex(c.r19()), "\n")
+	print("r20  ", hex(c.r20()), "\t")
+	print("r21  ", hex(c.r21()), "\n")
+	print("r22  ", hex(c.r22()), "\t")
+	print("r23  ", hex(c.r23()), "\n")
+	print("r24  ", hex(c.r24()), "\t")
+	print("r25  ", hex(c.r25()), "\n")
+	print("r26  ", hex(c.r26()), "\t")
+	print("r27  ", hex(c.r27()), "\n")
+	print("r28  ", hex(c.r28()), "\t")
+	print("r29  ", hex(c.r29()), "\n")
+	print("r30  ", hex(c.r30()), "\t")
+	print("r31  ", hex(c.r31()), "\n")
+	print("pc   ", hex(c.pc()), "\t")
+	print("link ", hex(c.link()), "\n")
+	print("lo   ", hex(c.lo()), "\t")
+	print("hi   ", hex(c.hi()), "\n")
+}
+
+func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
+func (c *sigctxt) sigsp() uintptr { return uintptr(c.sp()) }
+func (c *sigctxt) siglr() uintptr { return uintptr(c.link()) }
+func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }
+
+// preparePanic sets up the stack to look like a call to sigpanic.
+func (c *sigctxt) preparePanic(sig uint32, gp *g) {
+	// We arrange link, and pc to pretend the panicking
+	// function calls sigpanic directly.
+	// Always save LINK to stack so that panics in leaf
+	// functions are correctly handled. This smashes
+	// the stack frame but we're not going back there
+	// anyway.
+	sp := c.sp() - sys.MinFrameSize
+	c.set_sp(sp)
+	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.link()
+
+	pc := gp.sigpc
+
+	// If we don't recognize the PC as code
+	// but we do recognize the link register as code,
+	// then assume this was a call to non-code and treat like
+	// pc == 0, to make unwinding show the context.
+	if pc != 0 && findfunc(pc) == nil && findfunc(uintptr(c.link())) != nil {
+		pc = 0
+	}
+
+	// Don't bother saving PC if it's zero, which is
+	// probably a call to a nil func: the old link register
+	// is more useful in the stack trace.
+	if pc != 0 {
+		c.set_link(uint32(pc))
+	}
+
+	// In case we are panicking from external C code
+	c.set_r30(uint32(uintptr(unsafe.Pointer(gp))))
+	c.set_pc(uint32(funcPC(sigpanic)))
+}