X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=rpikern;a=blobdiff_plain;f=src%2Fstartup.s;h=84e7e94d0b4037cec5229b228900e0f530504cec;hp=ec157f666db98b0078ce4b386324be47c8f0fc1c;hb=38a008b8d1a3a20c401397b4e132fb578e5f0c10;hpb=e3851fa5fc01560a8ab799046b7cf0d2f35f18e8

diff --git a/src/startup.s b/src/startup.s
index ec157f6..84e7e94 100644
--- a/src/startup.s
+++ b/src/startup.s
@@ -1,8 +1,54 @@
+	.extern main
+
 	.section .startup
+	.code 32
+
+	.global startup
+startup:
+	cpsid if
+
+	@ stop all but one of the cores
+	mrc p15, 0, r0, c0, c0, 5
+	ands r0, r0, #0xff
+	bne exit
+
+	@ detect if we're running in hyp mode, and drop to svc
+	mrs r0, cpsr
+	and r1, r0, #0x1f
+	cmp r1, #0x1a
+	bne hypend
+
+	bic r0, #0x1f
+	orr r0, #0x13
+	@msr spsr_cxsf, r0
+	add r0, pc, #4
+	msr elr_hyp, r0
+	@eret
+	mov pc, r0
+hypend:
+
+	@ setup initial stacks, allow 4k stack for IRQs
+	@mov r0, #0x12	@ switch to IRQ mode
+	@msr cpsr, r0
+	@ldr sp, =_stacktop
+	@mov r0, #0x13	@ switch to supervisor mode
+	@msr cpsr, r0
+	ldr sp, =_stacktop - 4096
+
 	@ clear bss
 	ldr r0, =_bss_start
 	ldr r1, =_bss_size
+	cmp r1, #0
+	beq 1f		@ 0-sized bss, skip clear
 	mov r2, #0
 0:	str r2, [r0], #4
 	subs r1, #4
 	bne 0b
+1:
+	blx main
+
+	.global exit
+exit:	wfe
+	b exit
+
+@ vi:set filetype=armasm: