diff options
Diffstat (limited to 'lib/efi_loader/helloworld.c')
| -rw-r--r-- | lib/efi_loader/helloworld.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/lib/efi_loader/helloworld.c b/lib/efi_loader/helloworld.c new file mode 100644 index 00000000000..bd72822c0b7 --- /dev/null +++ b/lib/efi_loader/helloworld.c @@ -0,0 +1,247 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Hello world EFI application + * + * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de> + * + * 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 <efi_api.h> + +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"<none>"); + 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"<none>\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; + } + 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; + 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; + +out: + boottime->exit(handle, ret, 0, NULL); + + /* We should never arrive here */ + return ret; +} |