Minor cleanups, comment changes. No need to load 3 values when setting up

the stack for secondary cores, the other two values are only used for zeroing
bss on the primary core.  No need to store the size of the stack at the
top of the stack (seems to be a leftover instruction from some cut-n-paste).

sys/arm/arm/locore-v6.S

@@ -367,9 +367,9 @@ VA_TO_PA_POINTER(Lpagetable, boot_pt1)
 
 
 .Lstart:
-	.word	_edata
-	.word	_ebss
-	.word	svcstk
+	.word	_edata			/* Note that these three items are */
+	.word	_ebss			/* loaded with a single ldmia and */
+	.word	svcstk			/* must remain in order together. */
 
 .Lmainreturned:
 	.asciz	"main()	returned"
@@ -425,20 +425,19 @@ ASENTRY_NP(mpentry)
 	
 	bl	init_mmu
 
-	adr	r1, .Lstart
-	ldmia	r1, {r1, r2, sp}	/* Set initial stack and */
-	mrc	p15, 0,	r0, c0,	c0, 5
-	and	r0, r0,	#15
+	adr	r1, .Lstart+8		/* Get initstack pointer from */
+	ldr	sp, [r1]		/* startup data. */
+	mrc	CP15_MPIDR(r0)		/* Get processor id number. */
+	and	r0, r0,	#0x0f
 	mov	r1, #INIT_ARM_STACK_SIZE
-	mul	r2, r1,	r0
-	add	sp, sp,	r2
-	str	r1, [sp]
+	mul	r2, r1,	r0		/* Point sp to initstack */
+	add	sp, sp,	r2		/* area for this processor. */
 
 	/* Switch to virtual addresses.	*/
 	ldr	pc, =1f
 1:
 	mov	fp, #0			/* trace back starts here */
-	bl	_C_LABEL(init_secondary)	/* Off we go */
+	bl	_C_LABEL(init_secondary)/* Off we go, cpu id in r0. */
 
 	adr	r0, .Lmpreturned
 	b	_C_LABEL(panic)