.globl _start
.equ _start,0x0


.macro phys_setup
	mov r0, #0
	mcr p15, 0, r0, c7, c10, 5
	mrc p15, 0, r1, c15, c2, 0	@ get old remap registers
	mov r0, #0x6d0
	add r0, #0xb
	mcr p15, 0, r0, c15, c2, 0	@ set all data access to be device-nonshared
.endm

.macro phys_restore
	mcr p15, 0, r1, c15, c2, 0	@ restore
.endm

@ make sure we are in svc32 mode
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0xd3
msr cpsr,r0

@ clear the screen to green and start dma
@ code from dzo htc-vogue early printk

#define DOUBLERGB_GREEN 0x7e007e0
@ physical page of fb

@ htc values from ce, we can try the dzo values instead
@#define HTC_FB_PHYS 0x16800000
@#define HTC_FB_PHYS_END 0x16896000
#define HTC_FB_PHYS 0x00700000
#define HTC_FB_PHYS_END 0x00796000

@ offset from mdp phys, use {read,write}_d_mdp
#define BYPASS33 0x184
#define BYPASS34 0x188
#define BYPASS35 0x18c
#define BYPASS37 0x194
#define BYPASS40 0x1a0
#define BYPASS41 0x1a4

@ offset from mdp control regs phys, use {read_write}_d_mdp_control
#define DMACONFIG 0x44
#define INTSTATUS 0x24
#define INTCLEAR 0x28
#define DMASTART 0x80
#define VSYNC 0x8c

.text
.align 2	@ two bits must be zero, therefore align on word boundaries
_start:

@ clear the screen
ldr r5,=HTC_FB_PHYS
ldr r6,=HTC_FB_PHYS_END
ldr r4,=DOUBLERGB_GREEN	@ green
clearscreenloop:
	str r4,[r5]
	add r5, r5, #4
	cmp r5,r6
	ble clearscreenloop

mov r6, #HTC_FB_PHYS
@ clear one pixel
str r4,[r6]

@ mdp control registers
ldr r6, =0xaa200000
@ clear interrupt
waitforint:
	ldr r4, [r6, #INTSTATUS]
	cmp r4, r5
	beq waitforint
	str r4, [r6, #INTCLEAR]

@ the mdp phys address, not control registers
ldr r6, =0xaa210000

ldr r4, =0x14000f0
phys_setup
str r4, [r6, #0x184]
phys_restore

mov r4, #HTC_FB_PHYS
phys_setup
str r4, [r6, #BYPASS34]
phys_restore

ldr r4, =0x000001e0
phys_setup
str r4, [r6, #BYPASS35]
phys_restore

add r4, r4, #0
phys_setup
str r4, [r6, #BYPASS37]
phys_restore
phys_setup
str r4, [r6, #BYPASS40]
phys_restore

ldr r4, =0x566600c3
phys_setup
str r4, [r6, #BYPASS41]
phys_restore

@ keep updating the screen
dmaloop:

	@ mdp control registers
	ldr r6, =0xaa200000

	ldr r4, =0x0032616a
	phys_setup
	str r4, [r6, #DMACONFIG]
	phys_restore

	add r4, r4, #0
	phys_setup
	str r4, [r6, #VSYNC]
	phys_restore
	phys_setup
	str r4, [r6, #DMASTART]
	phys_restore

	add r5, r5, #0
	waitforint2:
		phys_setup
		ldr r4, [r6, #INTSTATUS]
		phys_restore
		cmp r4, r5
		ble waitforint2

	@ clear interrupt
	waitforint3:
		phys_setup
		ldr r4, [r6, #INTSTATUS]
		phys_restore
		cmp r4, r5
		beq waitforint3
	str r4, [r6, #INTCLEAR]

@ now clear a line

@ draw a line (480 pixels)
mov r6, #HTC_FB_PHYS
mov r5, #480		@ one line
ldr r4, =DOUBLERGB_GREEN

lineloop:
	str r4,[r6,r5]
	subs r5,r5,#4
	bne lineloop

@ and update the screen
b dmaloop

.data