// screeninit source taken over from https://github.com/AuroraWright/arm9loaderhax/tree/master/payload_stage2/arm11
// check there for license info
// thanks go to AuroraWright
#include <types.h>
#include <cpu.h>
#include <gic.h>
#include <pxi.h>

// see: https://github.com/AuroraWright/Luma3DS/blob/53209b9be0c264af00fb81b32146d27f0d9498ac/source/screen.h#L32-L34
#define PDN_GPU_CNT (*(vu8  *)0x10141200)
#define ARESCREENSINITIALIZED (PDN_GPU_CNT != 1)

#define BASE_BRIGHTNESS (0x1F)

static volatile struct fb {
     u8 *top_left;
     u8 *top_right;
     u8 *bottom;
} *const fb = (volatile struct fb *)0x23FFFE00;

void screen_init(void)
{
    char do_disco = !ARESCREENSINITIALIZED;

    *(vu32 *)0x10141200 = 0x1007F;
    *(vu32 *)0x10202014 = 0x00000001;
    *(vu32 *)0x1020200C &= 0xFFFEFFFE;

    *(vu32 *)0x10202240 = BASE_BRIGHTNESS;
    *(vu32 *)0x10202A40 = BASE_BRIGHTNESS;
    *(vu32 *)0x10202244 = 0x1023E;
    *(vu32 *)0x10202A44 = 0x1023E;

    //Top screen
    *(vu32 *)0x10400400 = 0x000001c2;
    *(vu32 *)0x10400404 = 0x000000d1;
    *(vu32 *)0x10400408 = 0x000001c1;
    *(vu32 *)0x1040040c = 0x000001c1;
    *(vu32 *)0x10400410 = 0x00000000;
    *(vu32 *)0x10400414 = 0x000000cf;
    *(vu32 *)0x10400418 = 0x000000d1;
    *(vu32 *)0x1040041c = 0x01c501c1;
    *(vu32 *)0x10400420 = 0x00010000;
    *(vu32 *)0x10400424 = 0x0000019d;
    *(vu32 *)0x10400428 = 0x00000002;
    *(vu32 *)0x1040042c = 0x00000192;
    *(vu32 *)0x10400430 = 0x00000192;
    *(vu32 *)0x10400434 = 0x00000192;
    *(vu32 *)0x10400438 = 0x00000001;
    *(vu32 *)0x1040043c = 0x00000002;
    *(vu32 *)0x10400440 = 0x01960192;
    *(vu32 *)0x10400444 = 0x00000000;
    *(vu32 *)0x10400448 = 0x00000000;
    *(vu32 *)0x1040045C = 0x00f00190;
    *(vu32 *)0x10400460 = 0x01c100d1;
    *(vu32 *)0x10400464 = 0x01920002;
    *(vu32 *)0x10400468 = 0x18300000;
    *(vu32 *)0x10400470 = 0x80341;
    *(vu32 *)0x10400474 = 0x00010501;
    *(vu32 *)0x10400478 = 0;
    *(vu32 *)0x10400490 = 0x000002D0;
    *(vu32 *)0x1040049C = 0x00000000;

    //Bottom screen
    *(vu32 *)0x10400500 = 0x000001c2;
    *(vu32 *)0x10400504 = 0x000000d1;
    *(vu32 *)0x10400508 = 0x000001c1;
    *(vu32 *)0x1040050c = 0x000001c1;
    *(vu32 *)0x10400510 = 0x000000cd;
    *(vu32 *)0x10400514 = 0x000000cf;
    *(vu32 *)0x10400518 = 0x000000d1;
    *(vu32 *)0x1040051c = 0x01c501c1;
    *(vu32 *)0x10400520 = 0x00010000;
    *(vu32 *)0x10400524 = 0x0000019d;
    *(vu32 *)0x10400528 = 0x00000052;
    *(vu32 *)0x1040052c = 0x00000192;
    *(vu32 *)0x10400530 = 0x00000192;
    *(vu32 *)0x10400534 = 0x0000004f;
    *(vu32 *)0x10400538 = 0x00000050;
    *(vu32 *)0x1040053c = 0x00000052;
    *(vu32 *)0x10400540 = 0x01980194;
    *(vu32 *)0x10400544 = 0x00000000;
    *(vu32 *)0x10400548 = 0x00000011;
    *(vu32 *)0x1040055C = 0x00f00140;
    *(vu32 *)0x10400560 = 0x01c100d1;
    *(vu32 *)0x10400564 = 0x01920052;
    *(vu32 *)0x10400568 = 0x18346500;
    *(vu32 *)0x10400570 = 0x80301;
    *(vu32 *)0x10400574 = 0x00010501;
    *(vu32 *)0x10400578 = 0;
    *(vu32 *)0x10400590 = 0x000002D0;
    *(vu32 *)0x1040059C = 0x00000000;

    if (do_disco) {
        for(u32 i = 0; i < 256; i++) {
            *(vu32 *)0x10400484 = 0x10101 * i;
            *(vu32 *)0x10400584 = 0x10101 * i;	
        }
    }

    //Set CakeBrah framebuffers
    fb->top_left = (u8 *)0x18300000;
    fb->top_right = (u8 *)0x18300000;
    fb->bottom = (u8 *)0x18346500;

    *(vu32 *)0x10400468 = (u32)fb->top_left;
    *(vu32 *)0x1040046c = (u32)fb->top_left;
    *(vu32 *)0x10400494 = (u32)fb->top_right;
    *(vu32 *)0x10400498 = (u32)fb->top_right;
    *(vu32 *)0x10400568 = (u32)fb->bottom;
    *(vu32 *)0x1040056c = (u32)fb->bottom;

    vu32 *REGs_PSC0 = (vu32 *)0x10400010,
         *REGs_PSC1 = (vu32 *)0x10400020;

    REGs_PSC0[0] = (u32)fb->top_left >> 3; //Start address
    REGs_PSC0[1] = (u32)(fb->top_left + 0x46500) >> 3; //End address
    REGs_PSC0[2] = 0; //Fill value
    REGs_PSC0[3] = (2 << 8) | 1; //32-bit pattern; start

    REGs_PSC1[0] = (u32)fb->bottom >> 3; //Start address
    REGs_PSC1[1] = (u32)(fb->bottom + 0x38400) >> 3; //End address
    REGs_PSC1[2] = 0; //Fill value
    REGs_PSC1[3] = (2 << 8) | 1; //32-bit pattern; start

    while(!((REGs_PSC0[3] & 2) && (REGs_PSC1[3] & 2)));
    return;
}

void set_brightness(u8 brightness)
{
    *(vu32 *)0x10202240 = brightness;
    *(vu32 *)0x10202A40 = brightness;
}

void pxi_interrupt_handler(__attribute__((unused)) u32 xrq_n)
{
    u8 msg = PXI_GetRemote();
    switch(msg) {
    case PXI_NOCMD:
        break;
    case PXI_SETBRIGHTNESS:
        set_brightness(PXI_Recv());
        break;
    }
    PXI_SetRemote(PXI_NOCMD);
    return;
}

void main(void)
{
    vu32 *arm11Entry = (vu32 *)0x1FFFFFFC;
    u32 entry;

    PXI_Reset();
    GIC_Reset();
    screen_init();

    // Clear ARM11 entrypoint
    *arm11Entry = 0;

    GIC_Configure(IRQ_PXI_SYNC, pxi_interrupt_handler);
    PXI_EnableIRQ();
    CPU_EnableIRQ();

    //Wait for the entrypoint to be set, then branch to it
    while((entry=*arm11Entry) == 0);

    CPU_DisableIRQ();
    PXI_DisableIRQ();
    ((void (*)())(entry))();
}