#include "reboot_payload.h"

#include "ams_bpc.h"

#define IRAM_PAYLOAD_MAX_SIZE 0x2F000
#define IRAM_PAYLOAD_BASE 0x40010000

static alignas(0x1000) u8 g_reboot_payload[IRAM_PAYLOAD_MAX_SIZE];
static alignas(0x1000) u8 g_ff_page[0x1000];
static alignas(0x1000) u8 g_work_page[0x1000];

void do_iram_dram_copy(void* buf, uintptr_t iram_addr, size_t size, int option)
{
    memcpy(g_work_page, buf, size);

    SecmonArgs args = {0};
    args.X[0] = 0xF0000201;             /* smcAmsIramCopy */
    args.X[1] = (uintptr_t)g_work_page; /* DRAM Address */
    args.X[2] = iram_addr;              /* IRAM Address */
    args.X[3] = size;                   /* Copy size */
    args.X[4] = option;                 /* 0 = Read, 1 = Write */
    svcCallSecureMonitor(&args);

    memcpy(buf, g_work_page, size);
}

void copy_to_iram(uintptr_t iram_addr, void* buf, size_t size)
{
    do_iram_dram_copy(buf, iram_addr, size, 1);
}

void copy_from_iram(void* buf, uintptr_t iram_addr, size_t size)
{
    do_iram_dram_copy(buf, iram_addr, size, 0);
}

static void clear_iram(void)
{
    memset(g_ff_page, 0xFF, sizeof(g_ff_page));
    for (size_t i = 0; i < IRAM_PAYLOAD_MAX_SIZE; i += sizeof(g_ff_page)) {
        copy_to_iram(IRAM_PAYLOAD_BASE + i, g_ff_page, sizeof(g_ff_page));
    }
}

static void inject_payload(void)
{
    printf("injecting\n");
    spsmInitialize();
    smExit();
    if (R_SUCCEEDED(amsBpcInitialize()) && R_SUCCEEDED(amsBpcSetRebootPayload(g_reboot_payload, 0x24000))) {
        spsmShutdown(true);
    }
}

static void inject_payload_legacy(void)
{
    printf("injecting (legacy)\n");
    clear_iram();
    for (size_t i = 0; i < IRAM_PAYLOAD_MAX_SIZE; i += 0x1000) {
        copy_to_iram(IRAM_PAYLOAD_BASE + i, &g_reboot_payload[i], 0x1000);
    }
    splSetConfig((SplConfigItem)65001, 2);
}

int reboot_to_payload(const char* path, bool legacy)
{
    bool can_reboot = true;
    FILE* f;
    f = fopen(path, "rb");
    if (f == NULL)
        can_reboot = false;
    else {
        fread(g_reboot_payload, 1, sizeof(g_reboot_payload), f);
        fclose(f);
    }

    if (can_reboot) {
        if (legacy)
            inject_payload_legacy();
        else
            inject_payload();
    }
    if (can_reboot)
        splExit();

    return 0;
}