arm

diff --git a/src/Makefile b/src/Makefile
index 718ee58..e00fd2c 100644
--- a/src/Makefile
+++ b/src/Makefile

@@ -1,6 +1,15 @@
 ../bin/mk: mkmk.sh
 	SYSNAME=`uname` export SYSNAME; \
-	OBJTYPE=`uname -m | sed 's;i.86;386;; s;amd64;x86_64;; s;/.*;;; s; ;;g; s/PowerMacintosh/power/; s/macppc/power/g; s/ppc64/power/g; s/ppc/power/g'` export OBJTYPE; \
+	OBJTYPE=`uname -m | sed ' \
+		s;i.86;386;; \
+		s;amd64;x86_64;; \
+		s;/.*;;; s; ;;g; \
+		s;armv4l;arm;g; \
+		s;PowerMacintosh;power;g; \
+		s;macppc;power;g; \
+		s;ppc64;power;g; \
+		s;ppc;power;g; \
+		'` export OBJTYPE; \
 	PATH=/bin:/usr/bin:/usr/local/bin:`pwd`/../bin:$$PATH export PATH; \
 	PLAN9=`pwd`/.. export PLAN9; \
 	sh -x mkmk.sh

diff --git a/src/libthread/Linux-arm-asm.s b/src/libthread/Linux-arm-asm.s
new file mode 100644
index 0000000..95c8aaa
--- /dev/null
+++ b/src/libthread/Linux-arm-asm.s

@@ -0,0 +1,53 @@
+ 
+.globl _tas
+_tas:
+	mov	r3, #0xCA000000
+	add	r3, r3, #0xFE0000
+	add	r3, r3, #0xBA00
+	add	r3, r3, #0xBE
+	swp	r3, r3, [r0]
+	mov	r0, r3
+	mov	pc, lr
+
+.globl getmcontext
+getmcontext:
+	/* r0 will be overwritten */
+	str	r1, [r0,#4]!
+	str	r2, [r0,#4]!
+	str	r3, [r0,#4]!
+	str	r4, [r0,#4]!
+	str	r5, [r0,#4]!
+	str	r6, [r0,#4]!
+	str	r7, [r0,#4]!
+	str	r8, [r0,#4]!
+	str	r9, [r0,#4]!
+	str	r10, [r0,#4]!
+	str	r11, [r0,#4]!
+	str	r12, [r0,#4]!
+	str	r13, [r0,#4]!
+	str	r14, [r0,#4]!
+	/* r15 is pc */
+	mov	r0, #0
+	mov	pc, lr
+
+.globl setmcontext
+setmcontext:
+	/* r0 will be overwritten */
+	ldr	r1, [r0,#4]!
+	ldr	r2, [r0,#4]!
+	ldr	r3, [r0,#4]!
+	ldr	r4, [r0,#4]!
+	ldr	r5, [r0,#4]!
+	ldr	r6, [r0,#4]!
+	ldr	r7, [r0,#4]!
+	ldr	r8, [r0,#4]!
+	ldr	r9, [r0,#4]!
+	ldr	r10, [r0,#4]!
+	ldr	r11, [r0,#4]!
+	ldr	r12, [r0,#4]!
+	ldr	r13, [r0,#4]!
+	ldr	r14, [r0,#4]!
+	/* r15 is pc */
+	mov	r0, #1
+	mov	pc, lr
+

diff --git a/src/libthread/Linux.c b/src/libthread/Linux.c
index dab12d3..5d03324 100644
--- a/src/libthread/Linux.c
+++ b/src/libthread/Linux.c

@@ -436,3 +436,43 @@
 	_exit(0);
 }
 
+#ifdef __arm__
+extern int getmcontext(mcontext_t*);
+extern int setmcontext(const mcontext_t*);
+
+void
+makecontext(ucontext_t *uc, void (*fn)(void), int argc, ...)
+{
+	int i, *sp;
+	va_list arg;
+	
+	sp = (int*)uc->uc_stack.ss_sp+uc->uc_stack.ss_size/4;
+	va_start(arg, argc);
+	for(i=0; i<4 && i<argc; i++)
+		uc->uc_mcontext.gregs[0] = va_arg(arg, uint);
+	uc->uc_mcontext.gregs[13] = (uint)sp;
+	uc->uc_mcontext.gregs[14] = (uint)fn;
+}
+
+int
+getcontext(ucontext_t *uc)
+{
+	return getmcontext(&uc->uc_mcontext);
+}
+
+int
+setcontext(const ucontext_t *uc)
+{
+	setmcontext(&uc->uc_mcontext);
+	return 0;	/* not reached */
+}
+
+int
+swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
+{
+	if(getcontext(oucp) == 0)
+		setcontext(ucp);
+	return 0;
+}
+#endif
+

diff --git a/src/mkhdr b/src/mkhdr
index b5d3965..2bb9ec0 100644
--- a/src/mkhdr
+++ b/src/mkhdr

@@ -1,9 +1,11 @@
 SYSNAME=`uname`
+# objtype rules also in Makefile
 OBJTYPE=`uname -m | sed '
 	s;i.86;386;;
 	s;amd64;x86_64;;
 	s;/.*;;;
 	s; ;;g;
+	s;armv4l;arm;g;
 	s;PowerMacintosh;power;g;
 	s;macppc;power;g;
 	s;ppc64;power;g;