Use extended mnemonics and ha16/lo16.

Remove wrong comment: that's a right shift, not a left shift.

plat/linuxppc/boot.s

@@ -32,7 +32,7 @@ begtext:
 
 	lwz r3, 0(sp)            ! r3 = argc
 	addi r4, sp, 4           ! r4 = argv
-	rlwinm r5, r3, 32-2, 2, 31 ! shift left 2 bits
+	srwi r5, r3, 2
 	add r5, r5, r4 
 	addi r5, r5, 8           ! r5 = env
 	

plat/linuxppc/libsys/_syscall.s

@@ -12,16 +12,7 @@
 
 .sect .text
 
-EINVAL = 22
-
-#define IFFALSE 4
-#define IFTRUE 12
-#define ALWAYS 20
-
-#define LT 0
-#define GT 1
-#define EQ 2
-#define OV 3
+#define EINVAL 22
 
 ! Perform a Linux system call.
 
@@ -32,21 +23,21 @@ __syscall:
 	lwz r4, 8(sp)
 	lwz r5, 12(sp)
 	sc 0
-	bclr IFFALSE, OV, 0
+	bnslr
 
 	! On error, r3 contains the errno.	
 	! It just so happens that errnos 1-34 are the same in Linux as in ACK.
-	cmpi cr0, 0, r3, 1
-	bc IFTRUE, LT, 2f
-	cmpi cr0, 0, r3, 34
-	bc IFTRUE, GT, 2f
+	cmpwi r3, 1
+	blt 2f
+	cmpwi r3, 34
+	bgt 2f
 
 3:
-	li32 r4, _errno
-	stw r3, 0(r4)
-	addi r3, r0, -1
-	bclr ALWAYS, 0, 0
+	lis r4, ha16[_errno]
+	stw r3, lo16[_errno](r4)
+	li r3, -1
+	blr
 
 2:
-	addi r3, r0, EINVAL
+	li r3, EINVAL
 	b 3b

plat/osxppc/boot.s

@@ -29,7 +29,7 @@ begtext:
 
 	lwz r3, 0(sp)            ! r3 = argc
 	addi r4, sp, 4           ! r4 = argv
-	rlwinm r5, r3, 32-2, 2, 31 ! shift left 2 bits
+	srwi r5, r3, 2
 	add r5, r5, r4
 	addi r5, r5, 8           ! r5 = env
 

plat/osxppc/libsys/set_errno.s

@@ -1,7 +1,7 @@
 .sect .text
 .define .set_errno
 .set_errno:
-	li32 r10, _errno
-	stw r3, 0(r10)		! set errno
-	addi r3, r0, -1		! return -1
-	bclr 20, 0, 0
+	lis r4, ha16[_errno]
+	stw r3, lo16[_errno](r4)	! set errno
+	li r3, -1			! return -1
+	blr