add powerpc64 port

src/thread/powerpc64/__set_thread_area.s

@@ -0,0 +1,8 @@
+.text
+.global __set_thread_area
+.type   __set_thread_area, %function
+__set_thread_area:
+	mr 13, 3
+	li  3, 0
+	blr
+

src/thread/powerpc64/__unmapself.s

@@ -0,0 +1,9 @@
+	.text
+	.global __unmapself
+	.type   __unmapself,%function
+__unmapself:
+	li      0, 91 # __NR_munmap
+	sc
+	li      0, 1 #__NR_exit
+	sc
+	blr

src/thread/powerpc64/clone.s

@@ -0,0 +1,47 @@
+.text
+.global __clone
+.type __clone, %function
+__clone:
+	# int clone(fn, stack, flags, arg, ptid, tls, ctid)
+	#            a  b       c     d     e    f    g
+	#            3  4       5     6     7    8    9
+	# pseudo C code:
+	# tid = syscall(SYS_clone,c,b,e,f,g);
+	# if (!tid) syscall(SYS_exit, a(d));
+	# return tid;
+
+	# create initial stack frame for new thread
+	clrrdi 4, 4, 4
+	li     0, 0
+	stdu   0,-32(4)
+
+	# save fn and arg to child stack
+	std    3,  8(4)
+	std    6, 16(4)
+
+	# shuffle args into correct registers and call SYS_clone
+	mr    3, 5
+	#mr   4, 4
+	mr    5, 7
+	mr    6, 8
+	mr    7, 9
+	li    0, 120  # SYS_clone = 120
+	sc
+
+	# if error, negate return (errno)
+	bns+  1f
+	neg   3, 3
+
+1:	# if we're the parent, return
+	cmpwi cr7, 3, 0
+	bnelr cr7
+
+	# we're the child. call fn(arg)
+	ld     3, 16(1)
+	ld    12,  8(1)
+	mtctr 12
+	bctrl
+
+	# call SYS_exit. exit code is already in r3 from fn return value
+	li    0, 1    # SYS_exit = 1
+	sc

src/thread/powerpc64/syscall_cp.s

@@ -0,0 +1,37 @@
+	.global __cp_begin
+	.hidden __cp_begin
+	.global __cp_end
+	.hidden __cp_end
+	.global __cp_cancel
+	.hidden __cp_cancel
+	.hidden __cancel
+	.global __syscall_cp_asm
+	.hidden __syscall_cp_asm
+	.text
+	.type   __syscall_cp_asm,%function
+__syscall_cp_asm:
+	# at enter: r3 = pointer to self->cancel, r4: syscall no, r5: first arg, r6: 2nd, r7: 3rd, r8: 4th, r9: 5th, r10: 6th
+__cp_begin:
+	# if (self->cancel) goto __cp_cancel
+	lwz   0, 0(3)
+	cmpwi cr7, 0, 0
+	bne-  cr7, __cp_cancel
+
+	# make syscall
+	mr    0,  4
+	mr    3,  5
+	mr    4,  6
+	mr    5,  7
+	mr    6,  8
+	mr    7,  9
+	mr    8, 10
+	sc
+
+__cp_end:
+	# return error ? -r3 : r3
+	bnslr+
+	neg 3, 3
+	blr
+
+__cp_cancel:
+	b __cancel