32blit-pico/file.cpp

#include <cstdint>
#include <cstring>
#include <functional>
#include <vector>

#include "pico/binary_info.h"

#include "ff.h"
#include "diskio.h"

#include "file.hpp"
#include "storage.hpp"

static FATFS fs;
static bool initialised = false;

// fatfs io funcs
DSTATUS disk_initialize(BYTE pdrv) {
  initialised = storage_init();
  return initialised ? RES_OK : STA_NOINIT;
}

DSTATUS disk_status(BYTE pdrv) {
  return initialised ? RES_OK : STA_NOINIT;
}

DRESULT disk_read(BYTE pdrv, BYTE *buff, LBA_t sector, UINT count) {
  static_assert(FF_MIN_SS == FF_MAX_SS);
  return storage_read(sector, 0, buff, FF_MIN_SS * count) == int32_t(FF_MIN_SS * count) ? RES_OK : RES_ERROR;
}

DRESULT disk_write(BYTE pdrv, const BYTE *buff, LBA_t sector, UINT count) {
  return storage_write(sector, 0, buff, FF_MIN_SS * count) == int32_t(FF_MIN_SS * count) ? RES_OK : RES_ERROR;
}

DRESULT disk_ioctl(BYTE pdrv, BYTE cmd, void* buff) {
  uint16_t block_size;
  uint32_t num_blocks;

  switch(cmd) {
    case CTRL_SYNC:
      return RES_OK;

    case GET_SECTOR_COUNT:
      get_storage_size(block_size, num_blocks);
      *(LBA_t *)buff = num_blocks;
      return RES_OK;

    case GET_BLOCK_SIZE:
      *(DWORD *)buff = 1;
      return RES_OK;
  }

  return RES_PARERR;
}

void init_fs() {
  auto res = f_mount(&fs, "", 1);

  // auto-format flash, but not SD cards
#ifndef STORAGE_SD
  if(res == FR_NO_FILESYSTEM) {
    printf("No filesystem found, formatting...\n");

    MKFS_PARM opts{};
    opts.fmt = FM_ANY | FM_SFD;
    res = f_mkfs("", &opts, fs.win, FF_MAX_SS);

    if(res != FR_OK) {
      printf("...failed! (%i)\n", res);
      return;
    }

    res = f_mount(&fs, "", 1);
  }
#endif

  if(res != FR_OK)
    printf("Failed to mount filesystem! (%i)\n", res);
}

static char save_path[32]; // max game title length is 24 + ".blit/" + "/"

const char *get_save_path() {
  const char *app_name = "_unknown";

  if(!directory_exists(".blit"))
    create_directory(".blit");

  app_name = "_unknown";

  // fint the program name in the binary info
  extern binary_info_t *__binary_info_start, *__binary_info_end;

  for(auto tag_ptr = &__binary_info_start; tag_ptr != &__binary_info_end ; tag_ptr++) {
    if((*tag_ptr)->type != BINARY_INFO_TYPE_ID_AND_STRING || (*tag_ptr)->tag != BINARY_INFO_TAG_RASPBERRY_PI)
      continue;

    auto id_str_tag = (binary_info_id_and_string_t *)*tag_ptr;

    if(id_str_tag->id == BINARY_INFO_ID_RP_PROGRAM_NAME) {
      app_name = id_str_tag->value;
      break;
    }
  }

  snprintf(save_path, sizeof(save_path), ".blit/%s/", app_name);

  // make sure it exists
  if(!directory_exists(save_path))
    create_directory(save_path);


  return save_path;
}