Subversion Repositories freemyipod

@
@
@    emBIOS Loader for iPod Nano 2G
@
@    Copyright 2010 TheSeven
@
@
@    This file is part of emBIOS.
@
@    emBIOS is free software: you can redistribute it and/or
@    modify it under the terms of the GNU General Public License as
@    published by the Free Software Foundation, either version 2 of the
@    License, or (at your option) any later version.
@
@    emBIOS is distributed in the hope that it will be useful,
@    but WITHOUT ANY WARRANTY; without even the implied warranty of
@    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
@    See the GNU General Public License for more details.
@
@    You should have received a copy of the GNU General Public License along
@    with emBIOS.  If not, see <http://www.gnu.org/licenses/>.
@
@

.global _start
_start:

        msr     cpsr_c, #0xd3
        mrc     p15, 0, r0,c1,c0
        bic     r0, r0, #1
        mcr     p15, 0, r0,c1,c0
        mov     r0, #0
        mcr     p15, 0, r0,c7,c5
        adr     lr, cacheflush_done

flushcache:
        mov     r0, #0
flushcache_loop:
        mcr     p15, 0, r0,c7,c14,2
        add     r10, r0, #0x10
        mcr     p15, 0, r10,c7,c14,2
        add     r10, r10, #0x10
        mcr     p15, 0, r10,c7,c14,2
        add     r10, r10, #0x10
        mcr     p15, 0, r10,c7,c14,2
        adds    r0, r0, #0x04000000
        bne     flushcache_loop
        mcr     p15, 0, r0,c7,c10,4
        mov     pc, lr

cacheflush_done:
        adr     r0, _start
        adr     r1, _stubend + 4
        mov     r2, #0x22000000
copyloop:
        cmp     r1, r0
        ldrhi   r3, [r0], #4
        strhi   r3, [r2], #4
        bhi     copyloop
        str     r1, [r2]
        mov     r0, #0x22000000
        add     pc, r0, #sramstart - _start
sramstart:

        adr     lr, values1
        ldmia   lr!, {r0-r13}
        str     r1, [r0,#0x88]
        str     r2, [r0,#0xf0]
        str     r4, [r3,#0x38]
        mov     r1, #0
        str     r7, [r0]
        str     r1, [r0,#0x04]
        str     r8, [r0,#0x10]
        str     r1, [r0,#0x14]
        str     r9, [r0,#0x20]
        str     r1, [r0,#0x24]
        str     r10, [r0,#0x30]
        str     r1, [r0,#0x34]
        str     r9, [r0,#0x40]
        str     r1, [r0,#0x44]
        str     r11, [r0,#0x50]
        str     r1, [r0,#0x54]
        str     r12, [r0,#0x60]
        str     r1, [r0,#0x64]
        str     r13, [r0,#0xa0]
        str     r1, [r0,#0xa4]
        str     r5, [r0,#0xb0]
        mov     r3, #1
        str     r3, [r0,#0xb4]
        str     r6, [r0,#0xc0]
        ldmia   lr, {r4-r14}
        str     r1, [r0,#0xc4]
        str     r6, [r0,#0xd0]
        str     r1, [r0,#0xd4]
        str     r6, [r0,#0xe0]
        str     r1, [r0,#0xe4]
        str     r7, [r0,#0xf0]
        str     r1, [r0,#0xf4]
        ldr     r3, [r8,#0x24]
        orr     r3, r3, #3
        str     r3, [r8,#0x24]
        ldr     r3, [r8,#0x28]
        bic     r3, r3, #0x4000
        str     r3, [r8,#0x28]
        mov     r3, #0x3C400000
        str     r1, [r3]
        str     r12, [r8,#0x0c]
        ldr     r3, [r8,#0x24]
        orr     r3, r3, #0x54
        str     r3, [r8,#0x24]
        mov     r3, #0x2000
waitpll1:
        subs    r3, r3, #1
        bne     waitpll1
        ldr     r3, [r8]
        bic     r3, r3, r5
        orr     r3, r3, r4
        str     r3, [r8]
        ldr     r3, [r8,#0x24]
        bic     r3, r3, #1
        str     r3, [r8,#0x24]
        mov     r3, #0x84
        str     r3, [r0,#0x68]
        str     r13, [r8,#0x04]
        mov     r3, #0xa000
waitpll2:
        subs    r3, r3, #1
        bne     waitpll2
        ldr     r3, [r8,#0x24]
        orr     r3, r3, #1
        str     r3, [r8,#0x24]
        mov     r3, #0x6000
waitpll3:
        subs    r3, r3, #1
        bne     waitpll3
        ldr     r3, [r8]
        bic     r3, r3, r9
        orr     r3, r3, r10
        str     r3, [r8]
        ldr     r3, [r8,#0x3c]
        bic     r3, r3, #0x400
        orr     r3, r3, #0x280
        str     r3, [r8,#0x3c]
        ldr     r3, [r8,#0x10]
        bic     r3, r3, #0x1f8
        orr     r3, r3, #0x37
        str     r3, [r8,#0x10]
        mrc     p15, 0, r3,c1,c0
        orr     r3, r3, #0xc0000000
        mcr     p15, 0, r3,c1,c0
        str     r11, [r8,#0x28]
        str     r14, [r8,#0x40]
        sub     r6, r0, #0x00800000
        mov     r5, #0xf700
        str     r5, [r6,#0x88]
        mov     r5, #0x1100
        orr     r5, r5, #0x11
        str     r5, [r0,#0x88]
        add     r4, r6, #0x00200000
        str     r1, [r4,#0x08]
        mov     r5, #0xf3
        str     r5, [r4]
        mov     r5, #0x10
        str     r5, [r4,#0x04]
        b       setuppmu

pmuinitdata:
        .byte 3, 0x39, 0x18, 0, 0x8c
        .byte 9, 0x13, 3, 0, 0, 7, 0, 5, 2, 0x6b, 0
        .byte 4, 0x1e, 0x12, 1, 0, 0x10
        .byte 6, 0x22, 0x2f, 1, 0, 0x10, 9, 1
        .byte 6, 0x31, 0x15, 1, 0x0f, 3, 0x15, 0
        .byte 1, 0x43, 0
        .byte 1, 0x4e, 0
        .byte 1, 0x58, 0
        .byte 5, 0x07, 0xb0, 0x0f, 0xfe, 0xfc, 0xff
        .byte 5, 0x0d, 0xdf, 0xaa, 0x4a, 5, 0x27
        .byte 0
        .align 2

val_006a49a5:
        .word 0x006a49a5

values1:
        .word 0x3CF00000 @ R0
        .word 0x00001111 @ R1
        .word 0x00000221 @ R2
        .word 0x38200000 @ R3
val_00990999:
        .word 0x00990999 @ R4
        .word 0x41001111 @ R5
        .word 0x11114444 @ R6
        .word 0x11221111 @ R7
        .word 0x11001744 @ R8
        .word 0x33333333 @ R9
        .word 0x11113333 @ R10
        .word 0x77721151 @ R11
        .word 0x12111111 @ R12
        .word 0x11111000 @ R13
        .word 0x60007000 @ R4
        .word 0x7F007F00 @ R5
        .word 0x44444444 @ R6
        .word 0x22222221 @ R7
        .word 0x3C500000 @ R8
        .word 0xFF00FF00 @ R9
        .word 0x20803180 @ R10
        .word 0xFFDFF7CF @ R11
        .word 0x00061800 @ R12
        .word 0x00021200 @ R13
        .word 0xFFFFEF7E @ R14

setuppmu:
        mov     sp, pc
        bl      getpowerok
        beq     poweroff
        adr     r2, pmuinitdata
pmuinitloop:
        ldrb    r3, [r2], #1
        movs    r3, r3
        beq     pmuinitdone
        ldrb    r1, [r2], #1
        mov     r0, #0xe6
        bl      i2csend
        b       pmuinitloop
pmuinitdone:
        orr     r12, r12, #0x00600000
        mov     r1, #1
        ldr     r0, [r12,#0x100]
        bic     r0, r0, #0x0f
        orr     r0, r0, #1
        str     r0, [r12,#0x100]
        str     r1, [r12,#0x10c]
        sub     r11, r12, #0x04d00000
        ldr     r0, [r11,#0x80]
        bic     r0, r0, #0x20000
        str     r0, [r11,#0x80]
        ldr     r0, [r11]
        bic     r0, r0, #0xc00
        orr     r0, r0, #0x500
        str     r0, [r11]
        mov     r0, #3
        str     r0, [r11,#0x04]
        mov     r0, #1
        bl      sleepms
        mov     r0, #0x200
        orr     r0, r0, #0xed
        str     r0, [r11,#0x08]
        ldr     r0, val_006a49a5
        str     r0, [r11,#0x10]
        mov     r0, #0x37
        str     r0, [r11,#0x0c]
        ldr     r1, [r11,#0x04]
        bic     r1, r1, #0x700
        orr     r0, r1, #0x200
        str     r0, [r11,#0x04]
        orr     r0, r1, #0x300
        str     r0, [r11,#0x04]
        str     r0, [r11,#0x04]
        orr     r0, r1, #0x100
        str     r0, [r11,#0x04]
        orr     r0, r1, #0x500
        str     r0, [r11,#0x04]
        ldr     r0, [r11,#0x08]
        orr     r0, r0, #0x1000
        str     r0, [r11,#0x08]
        ldr     r0, val_00990999
        str     r0, [r11,#0x38]
        ldr     r0, [r12,#0xf0]
        bic     r0, r0, #0xff000000
        bic     r0, r0, #0x00ff0000
        orr     r0, r0, #0x22000000
        orr     r0, r0, #0x00220000
        str     r0, [r12,#0xf0]
        mov     r0, #0xf0
        str     r0, [r12,#0xfc]
        sub     r10, r12, #0x00d00000
        ldr     r0, [r10]
        mov     r0, r0,lsr#20
        mov     r0, r0,lsl#20
        str     r0, [r10]
        mov     r1, #0x3a000
        orr     r1, r1, #0x980
        str     r1, [r10,#0x08]
        orr     r0, r0, #0x300000
        str     r0, [r10]
        bl      initlcd
        mov     r0, #0x3f
        mcr     p15, 0, r0,c6,c0,1   @ CS0: 4GB at offset 0 - everything
        mcr     p15, 0, r0,c6,c0,0   @ DS0: 4GB at offset 0 - everything
        mov     r0, #0x31
        mcr     p15, 0, r0,c6,c1,1   @ CS1: SRAM/SDRAM mirror
        mcr     p15, 0, r0,c6,c1,0   @ DS1: SRAM/SDRAM mirror
        add     r0, r0, #0x08000000
        mcr     p15, 0, r0,c6,c2,1   @ CS2: SDRAM
        mcr     p15, 0, r0,c6,c2,0   @ DS2: SDRAM
        mov     r0, #0x23
        add     r0, r0, #0x22000000
        mcr     p15, 0, r0,c6,c3,1   @ CS3: SRAM
        mcr     p15, 0, r0,c6,c3,0   @ DS3: SRAM
        mov     r0, #0x27
        add     r0, r0, #0x24000000
        mcr     p15, 0, r0,c6,c4,1   @ CS4: NOR flash
        mcr     p15, 0, r0,c6,c4,0   @ DS4: NOR flash
        mcr     p15, 0, r1,c6,c5,1   @ CS5: unused
        mcr     p15, 0, r1,c6,c5,0   @ DS5: unused
        mcr     p15, 0, r1,c6,c6,1   @ CS6: unused
        mcr     p15, 0, r1,c6,c6,0   @ DS6: unused
        mcr     p15, 0, r1,c6,c7,1   @ CS7: unused
        mcr     p15, 0, r1,c6,c7,0   @ DS7: unused
        mov     r0, #0x1e
        mcr     p15, 0, r0,c2,c0, 1  @ CS1-4: cacheable
        mcr     p15, 0, r0,c2,c0, 0  @ DS1-4: cacheable
        mcr     p15, 0, r0,c3,c0, 0  @ DS1-4: write cacheable
        mov     r0, #0x300
        add     r0, r0, #0xff
        mcr     p15, 0, r0,c5,c0, 1  @ CS0-4: full access
        mcr     p15, 0, r0,c5,c0, 0  @ DS0-4: full access
        mrc     p15, 0, r0,c1,c0
        orr     r0, r0, #5
        orr     r0, r0, #0x1000
        mcr     p15, 0, r0,c1,c0     @ Re-enable the Protection Unit and caches
        mov     r0, #0xe6
        mov     r1, #0x2a
        mov     r2, #6
        bl      i2csendbyte
        mov     r0, #0xe6
        mov     r1, #0x2b
        mov     r2, #4
        bl      i2csendbyte
        mov     r0, #0xe6
        mov     r1, #0x28
        mov     r2, #10
        bl      i2csendbyte
        mov     r0, #0xe6
        mov     r1, #0x29
        mov     r2, #1
        bl      i2csendbyte
        ldr     r1, _stubend + 4
        ldr     r0, _stubend
        add     r0, r1, r0
        mov     r2, #0x08000000
movepayloadloop:
        cmp     r0, r1
        ldrhi   r3, [r1], #4
        strhi   r3, [r2], #4
        bhi     movepayloadloop
        bl      flushcache
        mcr     p15, 0, r0,c7,c5
        mov     pc, #0x08000000


lcd_inittab_type2:
        .byte 5, 10
        .byte 3, 0xa4
        .byte 4, 0x01
        .byte 5, 150
        .byte 3, 0x01
        .byte 2, 0x01
        .byte 2, 0x00
        .byte 3, 0x02
        .byte 2, 0x03
        .byte 2, 0x00
        .byte 3, 0x03
        .byte 2, 0x12
        .byte 2, 0x30
        .byte 3, 0x08
        .byte 2, 0x04
        .byte 2, 0x04
        .byte 3, 0x0e
        .byte 4, 0x10
        .byte 3, 0x70
        .byte 2, 0x10
        .byte 2, 0x00
        .byte 3, 0x71
        .byte 4, 0x01
        .byte 3, 0x30
        .byte 4, 0x02
        .byte 3, 0x31
        .byte 2, 0x04
        .byte 2, 0x00
        .byte 3, 0x32
        .byte 4, 0x07
        .byte 3, 0x33
        .byte 2, 0x05
        .byte 2, 0x00
        .byte 3, 0x34
        .byte 4, 0x07
        .byte 3, 0x35
        .byte 2, 0x07
        .byte 2, 0x03
        .byte 3, 0x36
        .byte 2, 0x05
        .byte 2, 0x07
        .byte 3, 0x37
        .byte 4, 0x05
        .byte 3, 0x38
        .byte 2, 0x14
        .byte 2, 0x04
        .byte 3, 0x39
        .byte 4, 0x0e
        .byte 3, 0x40
        .byte 2, 0x02
        .byte 2, 0x02
        .byte 3, 0x41
        .byte 4, 0x03
        .byte 3, 0x42
        .byte 4, 0x00
        .byte 3, 0x43
        .byte 2, 0x02
        .byte 2, 0x00
        .byte 3, 0x44
        .byte 2, 0x07
        .byte 2, 0x07
        .byte 3, 0x45
        .byte 2, 0x04
        .byte 2, 0x07
        .byte 3, 0x46
        .byte 2, 0x05
        .byte 2, 0x05
        .byte 3, 0x47
        .byte 4, 0x02
        .byte 3, 0x48
        .byte 4, 0x04
        .byte 3, 0x49
        .byte 4, 0x04
        .byte 3, 0x60
        .byte 2, 0x02
        .byte 2, 0x02
        .byte 3, 0x61
        .byte 4, 0x03
        .byte 3, 0x62
        .byte 4, 0x00
        .byte 3, 0x63
        .byte 2, 0x02
        .byte 2, 0x00
        .byte 3, 0x64
        .byte 2, 0x07
        .byte 2, 0x07
        .byte 3, 0x65
        .byte 2, 0x04
        .byte 2, 0x07
        .byte 3, 0x66
        .byte 2, 0x05
        .byte 2, 0x05
        .byte 3, 0x68
        .byte 4, 0x04
        .byte 3, 0x69
        .byte 4, 0x04
        .byte 3, 0x07
        .byte 4, 0x01
        .byte 3, 0x18
        .byte 4, 0x01
        .byte 3, 0x10
        .byte 2, 0x16
        .byte 2, 0x90
        .byte 3, 0x11
        .byte 2, 0x01
        .byte 2, 0x00
        .byte 3, 0x12
        .byte 2, 0x01
        .byte 2, 0x17
        .byte 3, 0x13
        .byte 2, 0x0f
        .byte 2, 0x80
        .byte 3, 0x12
        .byte 2, 0x01
        .byte 2, 0x37
        .byte 3, 0x20
        .byte 4, 0x00
        .byte 3, 0x21
        .byte 4, 0x00
        .byte 3, 0x50
        .byte 4, 0x00
        .byte 3, 0x51
        .byte 4, 0xaf
        .byte 3, 0x52
        .byte 4, 0x00
        .byte 3, 0x53
        .byte 4, 0x83
        .byte 3, 0x90
        .byte 4, 0x03
        .byte 3, 0x91
        .byte 4, 0x00
        .byte 3, 0x92
        .byte 2, 0x01
        .byte 2, 0x01
        .byte 3, 0x98
        .byte 2, 0x04
        .byte 2, 0x00
        .byte 3, 0x99
        .byte 2, 0x13
        .byte 2, 0x02
        .byte 3, 0x9a
        .byte 2, 0x02
        .byte 2, 0x02
        .byte 3, 0x9b
        .byte 2, 0x02
        .byte 2, 0x00
        .byte 5, 100
        .byte 3, 0x07
        .byte 4, 0x21
        .byte 3, 0x12
        .byte 2, 0x01
        .byte 2, 0x37
        .byte 5, 1
        .byte 3, 0x07
        .byte 4, 0x21
        .byte 3, 0x12
        .byte 2, 0x11
        .byte 2, 0x37
        .byte 5, 100
        .byte 3, 0x07
        .byte 2, 0x02
        .byte 2, 0x33
        .byte 0

lcd_inittab_type3:
        .byte 1, 0x01
        .byte 5, 5
        .byte 1, 0x11
        .byte 5, 120
        .byte 1, 0x3a
        .byte 2, 0x65
        .byte 1, 0xab
        .byte 1, 0x35
        .byte 2, 0x00
        .byte 1, 0xf2
        .byte 2, 0x01
        .byte 1, 0xe0
        .byte 2, 0x71
        .byte 2, 0x76
        .byte 2, 0x25
        .byte 2, 0x01
        .byte 2, 0xa5
        .byte 2, 0x09
        .byte 2, 0x15
        .byte 2, 0x11
        .byte 1, 0xe1
        .byte 2, 0x40
        .byte 2, 0x21
        .byte 2, 0x64
        .byte 2, 0x13
        .byte 2, 0xf3
        .byte 2, 0x0b
        .byte 2, 0x00
        .byte 2, 0x00
        .byte 1, 0xe2
        .byte 2, 0x71
        .byte 2, 0x65
        .byte 2, 0x24
        .byte 2, 0x08
        .byte 2, 0x97
        .byte 2, 0x01
        .byte 2, 0x15
        .byte 2, 0x11
        .byte 1, 0xe3
        .byte 2, 0x51
        .byte 2, 0x01
        .byte 2, 0x62
        .byte 2, 0x13
        .byte 2, 0xf3
        .byte 2, 0x0b
        .byte 2, 0x00
        .byte 2, 0x00
        .byte 1, 0xe4
        .byte 2, 0x71
        .byte 2, 0x57
        .byte 2, 0x31
        .byte 2, 0x01
        .byte 2, 0x82
        .byte 2, 0x04
        .byte 2, 0x1f
        .byte 2, 0x11
        .byte 1, 0xe5
        .byte 2, 0x64
        .byte 2, 0x41
        .byte 2, 0x64
        .byte 2, 0x19
        .byte 2, 0xb3
        .byte 2, 0x09
        .byte 2, 0x00
        .byte 2, 0x00
        .byte 1, 0x29
        .byte 0

lcd_inittab_type7:
        .byte 1, 0x01
        .byte 5, 10
        .byte 1, 0xb4
        .byte 2, 0x00
        .byte 1, 0xb6
        .byte 2, 0x01
        .byte 1, 0xb7
        .byte 2, 0x00
        .byte 2, 0x00
        .byte 2, 0x02
        .byte 2, 0x00
        .byte 2, 0x06
        .byte 2, 0x26
        .byte 2, 0x2d
        .byte 2, 0x27
        .byte 2, 0x55
        .byte 2, 0x27
        .byte 1, 0xb8
        .byte 2, 0x10
        .byte 1, 0xb9
        .byte 2, 0x52
        .byte 2, 0x12
        .byte 2, 0x03
        .byte 1, 0xc0
        .byte 2, 0x0a
        .byte 2, 0x10
        .byte 2, 0x10
        .byte 1, 0xc2
        .byte 2, 0x14
        .byte 2, 0x23
        .byte 1, 0xc3
        .byte 2, 0x12
        .byte 2, 0x23
        .byte 1, 0xc6
        .byte 2, 0x48
        .byte 1, 0xe0
        .byte 2, 0x20
        .byte 2, 0x71
        .byte 2, 0x17
        .byte 2, 0x09
        .byte 2, 0x70
        .byte 2, 0x0c
        .byte 2, 0x13
        .byte 2, 0x25
        .byte 1, 0xe1
        .byte 2, 0x37
        .byte 2, 0x00
        .byte 2, 0x63
        .byte 2, 0x11
        .byte 2, 0xd9
        .byte 2, 0x00
        .byte 2, 0x12
        .byte 2, 0x01
        .byte 1, 0xe2
        .byte 2, 0x42
        .byte 2, 0x42
        .byte 2, 0x60
        .byte 2, 0x08
        .byte 2, 0xb4
        .byte 2, 0x07
        .byte 2, 0x0e
        .byte 2, 0x90
        .byte 1, 0xe3
        .byte 2, 0x47
        .byte 2, 0x60
        .byte 2, 0x66
        .byte 2, 0x09
        .byte 2, 0x6a
        .byte 2, 0x02
        .byte 2, 0x0e
        .byte 2, 0x09
        .byte 1, 0xe4
        .byte 2, 0x11
        .byte 2, 0x40
        .byte 2, 0x03
        .byte 2, 0x0a
        .byte 2, 0xc1
        .byte 2, 0x0d
        .byte 2, 0x17
        .byte 2, 0x30
        .byte 1, 0xe5
        .byte 2, 0x00
        .byte 2, 0x30
        .byte 2, 0x77
        .byte 2, 0x1c
        .byte 2, 0xfb
        .byte 2, 0x00
        .byte 2, 0x13
        .byte 2, 0x07
        .byte 1, 0xe6
        .byte 2, 0x01
        .byte 1, 0x35
        .byte 2, 0x00
        .byte 1, 0x36
        .byte 2, 0x00
        .byte 1, 0xf2
        .byte 2, 0x40
        .byte 1, 0xf3
        .byte 2, 0x50
        .byte 1, 0xfb
        .byte 2, 0x01
        .byte 1, 0x11
        .byte 5, 200
        .byte 1, 0xb1
        .byte 2, 0x16
        .byte 2, 0x03
        .byte 1, 0xb2
        .byte 2, 0x17
        .byte 2, 0x03
        .byte 1, 0x3a
        .byte 2, 0x65
        .byte 1, 0x29
        .byte 0

.align 2

lcd_initmapping:
        .word   lcd_inittab_type3 - lcd_initmapping_ref
        .word   lcd_inittab_type7 - lcd_initmapping_ref
        .word   lcd_inittab_type2 - lcd_initmapping_ref
        .word   lcd_inittab_type3 - lcd_initmapping_ref

initlcd:
        stmfd   sp!, {r4,r5,lr}
        bl      detectlcd
        sub     r12, r12, #0x04900000
        adr     r5, lcd_initmapping
        add     r5, r5, r0,lsl#2
        ldr     r5, [r5]
        add     r5, r5, pc
        mov     r0, #0xc00
lcd_initmapping_ref:
        orr     r0, r0, #1
        str     r0, [r12]
        mov     r0, #0x7f00
        orr     r0, r0, #0xff
        str     r0, [r12,#0x24]
        mov     r0, #0
        str     r0, [r12,#0x28]
        mov     r0, #1
        bl      sleepms
        mov     r0, #1
        str     r0, [r12,#0x28]
        mov     r0, #5
        bl      sleepms
initlcd_loop:
        adr     lr, initlcd_loop
        ldrb    r1, [r5], #1
        ldrb    r0, [r5], #1
        add     pc, pc, r1,lsl#2
        nop
        ldmfd   sp!, {r4,r5,pc}
        b       sendlcdc
        b       sendlcdd
        b       sendlcd2c
        b       sendlcd2d
        b       sleepms

sendlcd2c:
        ldr     r4, [r12,#0x1c]
        ands    r4, r4, #0x10
        bne     sendlcd2c
        mov     r4, r0,lsr#8
        str     r4, [r12,#0x04]
        and     r0, r0, #0xff
sendlcdc:
        ldr     r4, [r12,#0x1c]
        ands    r4, r4, #0x10
        bne     sendlcdc
        str     r0, [r12,#0x04]
        mov     pc, lr
sendlcd2d:
        ldr     r4, [r12,#0x1c]
        ands    r4, r4, #0x10
        bne     sendlcd2d
        mov     r4, r0,lsr#8
        str     r4, [r12,#0x40]
        and     r0, r0, #0xff
sendlcdd:
        ldr     r4, [r12,#0x1c]
        ands    r4, r4, #0x10
        bne     sendlcdd
        str     r0, [r12,#0x40]
        mov     pc, lr

detectlcd:
        mov     r12, #0x3c000000
        orr     r12, r12, #0xf00000
        ldr     r0, [r12,#0xd0]
        bic     r0, r0, #0x0f
        str     r0, [r12,#0xd0]
        ldr     r0, [r12,#0xe0]
        bic     r0, r0, #0xf0
        str     r0, [r12,#0xe0]
        ldr     r0, [r12,#0xd4]
        and     r0, r0, #1
        ldr     r1, [r12,#0xe4]
        and     r1, r1, #2
        orr     r0, r0, r1
        mov     pc, lr

getpowerok:
        stmfd   sp!, {lr}
        mov     r0, #0xe6
        mov     r1, #0x19
        bl      i2crecvbyte
        eor     r0, r0, #1
        ands    r0, r0, #1
        ldmnefd sp!, {pc}
        mov     r0, #0xe6
        mov     r1, #0x4b
        bl      i2crecvbyte
        ands    r0, r0, #4
        movne   r0, #1
        ldmnefd sp!, {pc}
        mov     r0, #0xe6
        mov     r1, #0x12
        bl      i2crecvbyte
        ands    r0, r0, #4
        movne   r0, #1
        ldmfd   sp!, {pc}

poweroff:
        mov     r0, #0xe6
        mov     r1, #0x0c
        mov     r2, #0x01
        bl      i2csendbyte
        b       poweroff

i2csendbyte:
        mov     r3, #0
@fallthrough

i2csend:
        stmfd   sp!, {r4,lr}
        mov     r12, #0x3C000000
        add     r12, r12, #0x00900000
        mov     r4, #0
        str     r4, [r12,#0x08]
        str     r0, [r12,#0x0c]
        mov     r4, #0xf0
        str     r4, [r12,#0x04]
        mov     r4, #0xb7
        str     r4, [r12]
        bl      i2cwait
        str     r1, [r12,#0x0c]
        str     r4, [r12]
        bl      i2cwait
        movs    r3, r3
        moveq   r0, r2
i2csend_write:
        ldrne   r0, [r2], #1
        str     r0, [r12,#0x0c]
        str     r4, [r12]
        bl      i2cwait
        subs    r3, r3, #1
        bhi     i2csend_write
        mov     r0, #0xd0
        str     r0, [r12,#0x04]
        str     r4, [r12]
i2csend_wait:
        ldr     r0, [r12,#0x04]
        tst     r0, #0x20
        bne     i2csend_wait
        ldmfd   sp!, {r4,pc}

i2crecvbyte:
        mov     r2, #0
        mov     r3, #1
@fallthrough

i2crecv:
        stmfd   sp!, {r0,r4,lr}
        mov     r12, #0x3C000000
        add     r12, r12, #0x00900000
        mov     r4, #0
        str     r4, [r12,#0x08]
        str     r0, [r12,#0x0c]
        mov     r4, #0xf0
        str     r4, [r12,#0x04]
        mov     r4, #0xb7
        str     r4, [r12]
        bl      i2cwait
        str     r1, [r12,#0x0c]
        str     r4, [r12]
        bl      i2cwait
        ldr     r0, [sp]
        orr     r0, r0, #1
        str     r1, [r12,#0x0c]
        mov     r0, #0xb0
        str     r0, [r12,#0x04]
        str     r4, [r12]
        bl      i2cwait
i2crecv_read:
        subs    r3, r3, #1
        moveq   r4, #0x37
        str     r4, [r12]
        bl      i2cwait
        ldr     r0, [r12,#0x0c]
        movs    r2, r2
        strne   r0, [r2], #1
        movs    r3, r3
        bne     i2crecv_read
        mov     r1, #0x90
        str     r1, [r12,#0x04]
        mov     r1, #0xb7
        str     r1, [r12]
i2crecv_wait:
        ldr     r1, [r12,#0x04]
        tst     r1, #0x20
        bne     i2crecv_wait
        ldmfd   sp!, {r0,r4,pc}

i2cwait:
        ldr     r0, [r12]
        tst     r0, #0x10
        beq     i2cwait
        mov     pc, lr


sleep10ms:
        mov     r0, #10
@ fallthrough

sleepms:
        mov     r2, #0xc8
        mul     r1, r0, r2
        mov     r2, #0x3c000000
        orr     r2, r2, #0x700000
        ldr     r0, [r2,#0x80]
        ldr     r0, [r2,#0x84]
        add     r1, r1, r0
sleepmsloop:
        ldr     r0, [r2,#0x80]
        ldr     r0, [r2,#0x84]
        cmp     r0, r1
        bmi     sleepmsloop
        mov     pc, lr

_stubend: