static u32 choose_mode_list()

in efi/libstub/gop.c [309:383]

• 64 lines of code
• 12 McCabe index (conditional complexity)

static u32 choose_mode_list(efi_graphics_output_protocol_t *gop)
{
	efi_status_t status;

	efi_graphics_output_protocol_mode_t *mode;
	efi_graphics_output_mode_info_t *info;
	unsigned long info_size;

	u32 max_mode, cur_mode;
	int pf;
	efi_pixel_bitmask_t pi;
	u32 m, w, h;
	u8 d;
	const char *dstr;
	bool valid;
	efi_input_key_t key;

	mode = efi_table_attr(gop, mode);

	cur_mode = efi_table_attr(mode, mode);
	max_mode = efi_table_attr(mode, max_mode);

	efi_printk("Available graphics modes are 0-%u\n", max_mode-1);
	efi_puts("  * = current mode\n"
		 "  - = unusable mode\n");
	for (m = 0; m < max_mode; m++) {
		status = efi_call_proto(gop, query_mode, m,
					&info_size, &info);
		if (status != EFI_SUCCESS)
			continue;

		pf = info->pixel_format;
		pi = info->pixel_information;
		w  = info->horizontal_resolution;
		h  = info->vertical_resolution;

		efi_bs_call(free_pool, info);

		valid = !(pf == PIXEL_BLT_ONLY || pf >= PIXEL_FORMAT_MAX);
		d = 0;
		switch (pf) {
		case PIXEL_RGB_RESERVED_8BIT_PER_COLOR:
			dstr = "rgb";
			break;
		case PIXEL_BGR_RESERVED_8BIT_PER_COLOR:
			dstr = "bgr";
			break;
		case PIXEL_BIT_MASK:
			dstr = "";
			d = pixel_bpp(pf, pi);
			break;
		case PIXEL_BLT_ONLY:
			dstr = "blt";
			break;
		default:
			dstr = "xxx";
			break;
		}

		efi_printk("Mode %3u %c%c: Resolution %ux%u-%s%.0hhu\n",
			   m,
			   m == cur_mode ? '*' : ' ',
			   !valid ? '-' : ' ',
			   w, h, dstr, d);
	}

	efi_puts("\nPress any key to continue (or wait 10 seconds)\n");
	status = efi_wait_for_key(10 * EFI_USEC_PER_SEC, &key);
	if (status != EFI_SUCCESS && status != EFI_TIMEOUT) {
		efi_err("Unable to read key, continuing in 10 seconds\n");
		efi_bs_call(stall, 10 * EFI_USEC_PER_SEC);
	}

	return cur_mode;
}