73 lines
2.3 KiB
C
73 lines
2.3 KiB
C
#include <stdint.h>
|
|
#include <stddef.h>
|
|
#include "fatfs/ff.h"
|
|
#include "fatfs/sdmmc/sdmmc.h"
|
|
#include "../launcher_path.h"
|
|
|
|
void *payload_loc = (void *)0x08000000;
|
|
unsigned int payload_offset = 0x22000;
|
|
unsigned int payload_size = 0x50000;
|
|
|
|
// This is where the loader writes the framebuffer offsets
|
|
struct framebuffers {
|
|
uint32_t *top_left;
|
|
uint32_t *top_right;
|
|
uint32_t *bottom;
|
|
} *framebuffers = (struct framebuffers *)0x23FFFE00;
|
|
|
|
#define screen_top_width 400
|
|
#define screen_top_height 240
|
|
#define screen_bottom_width 340
|
|
#define screen_bottom_height 240
|
|
#define screen_top_size (screen_top_width * screen_top_height * 3)
|
|
#define screen_bottom_size (screen_bottom_width * screen_bottom_height * 3)
|
|
|
|
void memset32(void *dest, uint32_t filler, uint32_t size)
|
|
{
|
|
uint32_t *dest32 = (uint32_t *)dest;
|
|
for (uint32_t i = 0; i < size / 4; i++) {
|
|
dest32[i] = filler;
|
|
}
|
|
}
|
|
|
|
void clear_screens() {
|
|
memset32(framebuffers->top_left, 0, screen_top_size);
|
|
memset32(framebuffers->top_right, 0, screen_top_size);
|
|
memset32(framebuffers->bottom, 0, screen_bottom_size);
|
|
}
|
|
|
|
// This is supposed to be a small-ish payload that loads a bigger payload.
|
|
// This exists because some payloads are too big to be loaded in the memory of some apps.
|
|
void main()
|
|
{
|
|
FATFS fs;
|
|
FIL handle;
|
|
unsigned int bytes_read;
|
|
|
|
// Mount the SD card
|
|
if (f_mount(&fs, "0:", 1) != FR_OK) return;
|
|
|
|
// Load the payload
|
|
if (f_open(&handle, "/" LAUNCHER_PATH, FA_READ) != FR_OK) return;
|
|
if (f_lseek(&handle, payload_offset) != FR_OK) return;
|
|
if (f_read(&handle, payload_loc, payload_size, &bytes_read) != FR_OK) return;
|
|
if (f_close(&handle) != FR_OK) return;
|
|
|
|
// Unmount the SD card
|
|
if (f_mount(NULL, "0:", 1) != FR_OK) return;
|
|
|
|
// This is mostly to adhere to the gateway "standard",
|
|
// so existing gateway payloads don't have to be modified.
|
|
// Write the framebuffer offsets to the places where gateway expects them
|
|
*(uint32_t **)0x080FFFC0 = framebuffers->top_left;
|
|
*(uint32_t **)0x080FFFC4 = framebuffers->top_right;
|
|
*(uint32_t **)0x080FFFD4 = framebuffers->bottom;
|
|
*(uint32_t *)0x080FFFD8 = 0; // Select top framebuffer?
|
|
|
|
// Loaded correctly. The rest is up to the payload.
|
|
clear_screens();
|
|
|
|
// Jump to the payload, right behind the interrupt vector table.
|
|
((void (*)())(payload_loc + 0x30))();
|
|
}
|