coto: own GBA/NDS IRQ handler ya know.

@this is Coto's IRQ handler
@----------------------------------interrupt request handler---------------------------------------------
@IRQ BIOS Setup (this is definitely from coto's asm)
@Note: MUST be on WRAM that is not protected, like VECTORS
@also known as : le hook

.global irqbiosinst
.type   irqbiosinst STT_FUNC
irqbiosinst:

    mov r0,#0
    MRC P15, 0 ,r0, c9,c1,0             @TCM Data TCM Base and Virtual Size
    MOV r0, r0, LSR #0xc
    MOV r0, r0, LSL #0xc
    LDR R1,=0x3ffc                      @IRQ handler
    add r0,r0,r1
    adr r2,inter_irq

    //test: ldr r1,=0xc070c070  @test should make dtcm+0x3ffc jump to garbage

    str r2,[r0]
    bx lr

.global irqexcepstack
irqexcepstack:
    .word   0x00000000  @r0     a1
    .word   0x00000000  @r1     a2
    .word   0x00000000  @r2     a3
    .word   0x00000000  @r3     a4
    .word   0x00000000  @r4     s1
    .word   0x00000000  @r5     s2
    .word   0x00000000  @r6     s3
    .word   0x00000000  @r7     s4
    .word   0x00000000  @r8     s5
    .word   0x00000000  @r9     s6
    .word   0x00000000  @r10    sl
    .word   0x00000000  @r11    ip
    .word   0x00000000  @r12    fp
    .word   0x00000000  @r13    sp
    .word   0x00000000  @r14    lr
    .word   0x00000000  @r15    pc

.global inter_irq
inter_irq:

@new NDS9 BIOS handler
ldr     r0,=irqexcepstack
stmia   r0,{r1-r13,r14}

@disable IME
ldr r12,=0x04000208
//mov r11,#0
str r12,[r12]

@ie / if
ldr r10,=0x04000210
ldr r9,[r10]
ldr r8,=0x04000214
ldr r7,[r8]

and r7,r7,r9 @mask only if set on ie (switch)

//* IRQ handler */
stmdb sp!,{r0-r12,r14}

    MOV r0,r7,ror #0    // case 0
        ldrcs r0,=vblank_thread
        movcs lr,pc
        bxcs r0

    MOV r0,r7,ror #1    // case 1
        ldrcs r0,=hblank_thread
        movcs lr,pc
        bxcs r0

    MOV r0,r7,ror #2    // case 2
        ldrcs r0,=vcount_thread
        movcs lr,pc
        bxcs r0

    MOV r0,r7,ror #18   // case 18
        ldrcs r0,=fifo_thread
        movcs lr,pc
        bxcs r0

ldmia sp!,{r0-r12,r14}

/* IRQ Handler end ,dont modify anything else */

@bios flag mix
MRC P15, 0 ,r0, c9,c1,0             @TCM Data TCM Base and Virtual Size
MOV r0, r0, LSR #0xC
MOV r0, r0, LSL #0xC

ldr r1,=0x3ff8                      @dtcm+0x3ff8 = BIOS Interrupt Flags - Check bits (ARM9)
ldr r6,[r0,r1]

orr r7,r7,r6                        @if = r7 / bios f = r6

str r7,[r8]                         @serve IF
str r7,[r0,r1]

@enable IME
mov r11,#1
str r11,[r12]

ldr     r0,=irqexcepstack
ldmia   r0,{r1-r13,r14}

bx r14 @back to NDS9bios (it will return from IRQ PSR mode there)