// SPDX-License-Identifier: GPL-2.0+ /* * Hello world EFI application * * Copyright 2020, Heinrich Schuchardt * * This test program is used to test the invocation of an EFI application. * It writes * * * a greeting * * the firmware's UEFI version * * the installed configuration tables * * the boot device's device path and the file path * * to the console. */ #include static const efi_guid_t loaded_image_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID; static const efi_guid_t device_path_to_text_protocol_guid = EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID; static const efi_guid_t device_path_guid = EFI_DEVICE_PATH_PROTOCOL_GUID; static const efi_guid_t fdt_guid = EFI_FDT_GUID; static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID; static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID; static struct efi_system_table *systable; static struct efi_boot_services *boottime; static struct efi_simple_text_output_protocol *con_out; /* * Print an unsigned 32bit value as decimal number to an u16 string * * @value: value to be printed * @buf: pointer to buffer address * on return position of terminating zero word */ static void uint2dec(u32 value, u16 **buf) { u16 *pos = *buf; int i; u16 c; u64 f; /* * Increment by .5 and multiply with * (2 << 60) / 1,000,000,000 = 0x44B82FA0.9B5A52CC * to move the first digit to bit 60-63. */ f = 0x225C17D0; f += (0x9B5A52DULL * value) >> 28; f += 0x44B82FA0ULL * value; for (i = 0; i < 10; ++i) { /* Write current digit */ c = f >> 60; if (c || pos != *buf) *pos++ = c + '0'; /* Eliminate current digit */ f &= 0xfffffffffffffff; /* Get next digit */ f *= 0xaULL; } if (pos == *buf) *pos++ = '0'; *pos = 0; *buf = pos; } /** * print_uefi_revision() - print UEFI revision number */ static void print_uefi_revision(void) { u16 rev[13] = {0}; u16 *buf = rev; u16 digit; uint2dec(systable->hdr.revision >> 16, &buf); *buf++ = '.'; uint2dec(systable->hdr.revision & 0xffff, &buf); /* Minor revision is only to be shown if non-zero */ digit = *--buf; if (digit == '0') { *buf = 0; } else { *buf++ = '.'; *buf = digit; } con_out->output_string(con_out, u"Running on UEFI "); con_out->output_string(con_out, rev); con_out->output_string(con_out, u"\r\n"); } /** * print_config_tables() - print configuration tables */ static void print_config_tables(void) { efi_uintn_t i; /* Find configuration tables */ for (i = 0; i < systable->nr_tables; ++i) { if (!memcmp(&systable->tables[i].guid, &fdt_guid, sizeof(efi_guid_t))) con_out->output_string (con_out, u"Have device tree\r\n"); if (!memcmp(&systable->tables[i].guid, &acpi_guid, sizeof(efi_guid_t))) con_out->output_string (con_out, u"Have ACPI 2.0 table\r\n"); if (!memcmp(&systable->tables[i].guid, &smbios_guid, sizeof(efi_guid_t))) con_out->output_string (con_out, u"Have SMBIOS table\r\n"); } } /** * print_load_options() - print load options * * @systable: system table * @con_out: simple text output protocol */ static void print_load_options(struct efi_loaded_image *loaded_image) { /* Output the load options */ con_out->output_string(con_out, u"Load options: "); if (loaded_image->load_options_size && loaded_image->load_options) con_out->output_string(con_out, (u16 *)loaded_image->load_options); else con_out->output_string(con_out, u""); con_out->output_string(con_out, u"\r\n"); } /** * print_device_path() - print device path * * @device_path: device path to print * @dp2txt: device path to text protocol */ static efi_status_t print_device_path(struct efi_device_path *device_path, struct efi_device_path_to_text_protocol *dp2txt) { u16 *string; efi_status_t ret; if (!device_path) { con_out->output_string(con_out, u"\r\n"); return EFI_SUCCESS; } string = dp2txt->convert_device_path_to_text(device_path, true, false); if (!string) { con_out->output_string (con_out, u"Cannot convert device path to text\r\n"); return EFI_OUT_OF_RESOURCES; } con_out->output_string(con_out, string); con_out->output_string(con_out, u"\r\n"); ret = boottime->free_pool(string); if (ret != EFI_SUCCESS) { con_out->output_string(con_out, u"Cannot free pool memory\r\n"); return ret; } return EFI_SUCCESS; } /** * efi_main() - entry point of the EFI application. * * @handle: handle of the loaded image * @systab: system table * Return: status code */ efi_status_t EFIAPI efi_main(efi_handle_t handle, struct efi_system_table *systab) { struct efi_loaded_image *loaded_image; struct efi_device_path_to_text_protocol *device_path_to_text; struct efi_device_path *device_path; efi_status_t ret; systable = systab; boottime = systable->boottime; con_out = systable->con_out; /* UEFI requires CR LF */ con_out->output_string(con_out, u"Hello, world!\r\n"); print_uefi_revision(); print_config_tables(); /* Get the loaded image protocol */ ret = boottime->open_protocol(handle, &loaded_image_guid, (void **)&loaded_image, NULL, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL); if (ret != EFI_SUCCESS) { con_out->output_string (con_out, u"Cannot open loaded image protocol\r\n"); goto out; } print_load_options(loaded_image); /* Get the device path to text protocol */ ret = boottime->locate_protocol(&device_path_to_text_protocol_guid, NULL, (void **)&device_path_to_text); if (ret != EFI_SUCCESS) { con_out->output_string (con_out, u"Cannot open device path to text protocol\r\n"); goto out; } if (!loaded_image->device_handle) { con_out->output_string (con_out, u"Missing device handle\r\n"); goto out; } ret = boottime->open_protocol(loaded_image->device_handle, &device_path_guid, (void **)&device_path, NULL, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL); if (ret != EFI_SUCCESS) { con_out->output_string (con_out, u"Missing device path for device handle\r\n"); goto out; } con_out->output_string(con_out, u"Boot device: "); ret = print_device_path(device_path, device_path_to_text); if (ret != EFI_SUCCESS) goto out; con_out->output_string(con_out, u"File path: "); ret = print_device_path(loaded_image->file_path, device_path_to_text); if (ret != EFI_SUCCESS) goto out; out: boottime->exit(handle, ret, 0, NULL); /* We should never arrive here */ return ret; }