file.c

#include "file.h"

/* Public functions ----------------------------------------------------------*/
EFI_FILE_HANDLE uefi_get_volume(EFI_HANDLE image)
{
  EFI_LOADED_IMAGE *loaded_image = NULL;
  EFI_GUID lipGuid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
  EFI_FILE_IO_INTERFACE *IOVolume = NULL;
  EFI_GUID fsGuid = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
  EFI_FILE_HANDLE Volume;

  /* 1. Get the loaded image protocol interface for our "image". */
  uefi_call_wrapper(BS->HandleProtocol, 3, image, &lipGuid,
                    (void **)&loaded_image);

  /* 2. Get the volume handle. */
  uefi_call_wrapper(BS->HandleProtocol, 3, loaded_image->DeviceHandle, &fsGuid,
                    (VOID *)&IOVolume);
  uefi_call_wrapper(IOVolume->OpenVolume, 2, IOVolume, &Volume);

  return Volume;
}

UINT64 uefi_get_file_size(EFI_FILE_HANDLE file_handle)
{
  UINT64 ret = 0;
  EFI_FILE_INFO *FileInfo = NULL;

  FileInfo = LibFileInfo(file_handle);

  ret = FileInfo->FileSize;
  FreePool(FileInfo);
  return ret;
}

EFI_STATUS uefi_open_file(EFI_FILE_HANDLE volume,
                          const CHAR16 *filename,
                          EFI_FILE_HANDLE *file_handle)
{
  EFI_STATUS status = EFI_SUCCESS;
  status = uefi_call_wrapper(
      volume->Open, 5,
      volume,
      file_handle,
      filename,
      EFI_FILE_MODE_READ,
      EFI_FILE_READ_ONLY | EFI_FILE_HIDDEN | EFI_FILE_SYSTEM);

  if (EFI_ERROR(status))
  {
    Print(L"Failed to open file: %d\n", status);
  }

  return status;
}

EFI_STATUS uefi_close_file(EFI_FILE_HANDLE file_handle)
{
  EFI_STATUS status = EFI_SUCCESS;
  status = uefi_call_wrapper(file_handle->Close, 1, file_handle);

  if (EFI_ERROR(status))
  {
    Print(L"Failed to close file: %d\n", status);
  }

  return status;
}

EFI_STATUS uefi_read_file(EFI_FILE_HANDLE file_handle,
                          UINT8 *buffer, UINT64 size)
{
  EFI_STATUS status = EFI_SUCCESS;
  UINT64 read_size = size;
  status = uefi_call_wrapper(file_handle->Read, 3,
                             file_handle, &read_size,
                             buffer);
  if (EFI_ERROR(status))
  {
    Print(L"Failed to close file: %d\n", status);
  }
  else if (read_size != size)
  {
    Print(L"Can't get %d bytes, actual reading size: %d\n", size, read_size);
  }

  return status;
}