libthread: context switching for arm, still not complete

src/libthread/Linux-arm-context.s

@@ -0,0 +1,41 @@
+.globl mygetmcontext
+mygetmcontext:
+	str	r1, [r0,#4]
+	str	r2, [r0,#8]
+	str	r3, [r0,#12]
+	str	r4, [r0,#16]
+	str	r5, [r0,#20]
+	str	r6, [r0,#24]
+	str	r7, [r0,#28]
+	str	r8, [r0,#32]
+	str	r9, [r0,#36]
+	str	r10, [r0,#40]
+	str	r11, [r0,#44]
+	str	r12, [r0,#48]
+	str	r13, [r0,#52]
+	str	r14, [r0,#56]
+	/* store 1 as r0-to-restore */
+	mov	r1, #1
+	str	r1, [r0]
+	/* return 0 */
+	mov	r0, #0
+	mov	pc, lr
+
+.globl mysetmcontext
+mysetmcontext:
+	ldr	r1, [r0,#4]
+	ldr	r2, [r0,#8]
+	ldr	r3, [r0,#12]
+	ldr	r4, [r0,#16]
+	ldr	r5, [r0,#20]
+	ldr	r6, [r0,#24]
+	ldr	r7, [r0,#28]
+	ldr	r8, [r0,#32]
+	ldr	r9, [r0,#36]
+	ldr	r10, [r0,#40]
+	ldr	r11, [r0,#44]
+	ldr	r12, [r0,#48]
+	ldr	r13, [r0,#52]
+	ldr	r14, [r0,#56]
+	ldr	r0, [r0]
+	mov	pc, lr