This function reads the requested number of blocks from the device. All the\r
blocks are read, or an error is returned.\r
If EFI_DEVICE_ERROR, EFI_NO_MEDIA,_or EFI_MEDIA_CHANGED is returned and\r
This function reads the requested number of blocks from the device. All the\r
blocks are read, or an error is returned.\r
If EFI_DEVICE_ERROR, EFI_NO_MEDIA,_or EFI_MEDIA_CHANGED is returned and\r