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// 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_uefi_revision() - print UEFI revision number
*/
static void print_uefi_revision(void)
{
u16 rev[] = L"0.0.0";
rev[0] = (systable->hdr.revision >> 16) + '0';
rev[4] = systable->hdr.revision & 0xffff;
for (; rev[4] >= 10;) {
rev[4] -= 10;
++rev[2];
}
/* Third digit is only to be shown if non-zero */
if (rev[4])
rev[4] += '0';
else
rev[3] = 0;
con_out->output_string(con_out, L"Running on UEFI ");
con_out->output_string(con_out, rev);
con_out->output_string(con_out, L"\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, L"Have device tree\r\n");
if (!memcmp(&systable->tables[i].guid, &acpi_guid,
sizeof(efi_guid_t)))
con_out->output_string
(con_out, L"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, L"Have SMBIOS table\r\n");
}
}
/**
* print_load_options() - print load options
*
* @systable: system table
* @con_out: simple text output protocol
*/
void print_load_options(struct efi_loaded_image *loaded_image)
{
/* Output the load options */
con_out->output_string(con_out, L"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, L"<none>");
con_out->output_string(con_out, L"\r\n");
}
/**
* print_device_path() - print device path
*
* @device_path: device path to print
* @dp2txt: device path to text protocol
*/
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, L"<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, L"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, L"\r\n");
ret = boottime->free_pool(string);
if (ret != EFI_SUCCESS) {
con_out->output_string(con_out, L"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, L"Hello, world!\r\n");
print_uefi_revision();
print_config_tables();
/* Get the loaded image protocol */
ret = boottime->handle_protocol(handle, &loaded_image_guid,
(void **)&loaded_image);
if (ret != EFI_SUCCESS) {
con_out->output_string
(con_out, L"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, L"Cannot open device path to text protocol\r\n");
goto out;
}
if (!loaded_image->device_handle) {
con_out->output_string
(con_out, L"Missing device handle\r\n");
goto out;
}
ret = boottime->handle_protocol(loaded_image->device_handle,
&device_path_guid,
(void **)&device_path);
if (ret != EFI_SUCCESS) {
con_out->output_string
(con_out, L"Missing device path for device handle\r\n");
goto out;
}
con_out->output_string(con_out, L"Boot device: ");
ret = print_device_path(device_path, device_path_to_text);
if (ret != EFI_SUCCESS)
goto out;
con_out->output_string(con_out, L"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;
}
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