Add support for SMP booting following the RealView Boot Monitor booting

protocol but without WFI since the GIC isn't set up.

2 files changed, 27 insertions, 5 deletions

diff --git a/boot.S b/boot.S
index 4aedd35..884e46b 100644
--- a/boot.S
+++ b/boot.S
@@ -22,9 +22,31 @@
 	.globl	_start
 _start:
 	@
+	@ CPU initialisation
+	@
+	mrc	p15, 0, r0, c0, c0, 5		@ MPIDR (ARMv7 only)
+	and	r0, r0, #15			@ CPU number
+	cmp	r0, #0				@ primary CPU?
+	beq	2f
+
+	@
+	@ Secondary CPUs (following the RealView SMP booting protocol)
+	@
+	ldr	r1, =filesystem - 0x100
+	adr	r2, 1f
+	ldmia	r2, {r3 - r6}			@ move the code to a location
+	stmia	r1, {r3 - r6}			@ less likely to be overridden
+	ldr	r0, =0x10000030			@ RealView SYS_FLAGS register
+	mov	pc, r1				@ branch to the relocated code
+1:	ldr	r1, [r0]
+	cmp	r1, #0
+	beq	1b
+	mov	pc, r1				@ branch to the given address
+
+	@
 	@ UART initialisation (38400 8N1)
 	@
-	ldr	r0, =0x10009000			@ UART base (RealView/EB)
+2:	ldr	r0, =0x10009000			@ UART base (RealView/EB)
 	mov	r1, #0x10			@ ibrd
 	str	r1, [r0, #0x24]
 	mov	r1, #0xc300
diff --git a/model.lds b/model.lds
index 187ba9f..45df047 100644
--- a/model.lds
+++ b/model.lds
@@ -25,18 +25,18 @@ INPUT(./uImage)
 INPUT(./filesystem.cpio.gz)
 INPUT(./boot.o)
 
-PHYS = 0x70000000;
+PHYS_OFFSET = 0x00000000;
 
 SECTIONS
 {
-	. = PHYS;
+	. = PHYS_OFFSET;
 	.text : { boot.o }
 
-	. = PHYS + 0x8000 - 0x40;
+	. = PHYS_OFFSET + 0x8000 - 0x40;
 	kernel = . + 0x40;
 	.kernel : { ./uImage }
 
-	. = PHYS + 0x00800000;
+	. = PHYS_OFFSET + 0x00800000;
 	filesystem = .;
 	.filesystem : { ./filesystem.cpio.gz }
 	fs_size = . - filesystem;