main.c

#include <switch.h>

void __libnx_initheap(void) { }
void __appInit(void)        { }
void __appExit(void)        { }

#define DISP_IO_BASE 0x54200000
#define DISP_IO_SIZE (8 * 0x1000)

#define DC_CMD_INT_ENABLE              0xe4
#   define CMU_LUT_CONFLICT_INT_ENABLE (1 << 22)
#define DC_CMD_STATE_CONTROL           0x104
#   define GENERAL_ACT_REQ             (1 <<  0)
#   define WIN_A_ACT_REQ               (1 <<  1)
#   define WIN_B_ACT_REQ               (1 <<  2)
#   define WIN_C_ACT_REQ               (1 <<  3)
#   define WIN_D_ACT_REQ               (1 <<  4)
#   define CURSOR_ACT_REQ              (1 <<  7)
#   define GENERAL_UPDATE              (1 <<  8)
#   define WIN_A_UPDATE                (1 <<  9)
#   define WIN_B_UPDATE                (1 << 10)
#   define WIN_C_UPDATE                (1 << 11)
#   define WIN_D_UPDATE                (1 << 12)
#   define CURSOR_UPDATE               (1 << 15)
#   define NC_HOST_TRIG_ENABLE         (1 << 24)
#define DC_COM_CMU_CSC_KRR             0xca8
#define DC_COM_CMU_CSC_KGR             0xcac
#define DC_COM_CMU_CSC_KBR             0xcb0
#define DC_COM_CMU_CSC_KRG             0xcb4
#define DC_COM_CMU_CSC_KGG             0xcb8
#define DC_COM_CMU_CSC_KBG             0xcbc
#define DC_COM_CMU_CSC_KRB             0xcc0
#define DC_COM_CMU_CSC_KGB             0xcc4
#define DC_COM_CMU_CSC_KBB             0xcc8
#define DC_DISP_DISP_COLOR_CONTROL     0x10c0
#   define DISP_COLOR_SWAP             (1 << 16)
#   define BLANK_COLOR                 (1 << 17)
#   define NON_BASE_COLOR              (1 << 18)
#   define CMU_ENABLE                  (1 << 20)

int main(int argc, char **argv) {
    Result rc;

    uint64_t mmio_base, mmio_size;
    rc = svcQueryIoMapping(&mmio_base, &mmio_size, DISP_IO_BASE, DISP_IO_SIZE);
    if (R_FAILED(rc))
        diagAbortWithResult(rc);

    rc = svcSetThreadPriority(CUR_THREAD_HANDLE, 0x3f);
    if (R_FAILED(rc))
        diagAbortWithResult(rc);

    while (true) {
        svcSleepThread(1e9);

        uint32_t interrupts = *(volatile uint32_t *)(mmio_base + DC_CMD_INT_ENABLE);
        interrupts &= ~CMU_LUT_CONFLICT_INT_ENABLE;
        *(volatile uint32_t *)(mmio_base + DC_CMD_INT_ENABLE) = interrupts;

        uint32_t color_control = *(volatile uint32_t *)(mmio_base + DC_DISP_DISP_COLOR_CONTROL);

        color_control &= ~CMU_ENABLE;
        *(volatile uint32_t *)(mmio_base + DC_DISP_DISP_COLOR_CONTROL) = color_control;
        *(volatile uint32_t *)(mmio_base + DC_CMD_STATE_CONTROL) = GENERAL_ACT_REQ;

        for (int i = 0; i < 9; ++i) {
            volatile uint32_t test = *(volatile uint32_t *)(mmio_base + DC_COM_CMU_CSC_KRR + i * sizeof(uint32_t));
            (void)test;
        }
    }

    return 0;
}