helloworld.c
2.21 KB
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/*
* EFI hello world
*
* Copyright (c) 2016 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program demonstrates calling a boottime service.
* It writes a greeting and the load options to the console.
*/
#include <common.h>
#include <efi_api.h>
static const efi_guid_t loaded_image_guid = LOADED_IMAGE_GUID;
static const efi_guid_t fdt_guid = EFI_FDT_GUID;
static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
static int hw_memcmp(const void *buf1, const void *buf2, size_t length)
{
const u8 *pos1 = buf1;
const u8 *pos2 = buf2;
for (; length; --length) {
if (*pos1 != *pos2)
return *pos1 - *pos2;
++pos1;
++pos2;
}
return 0;
}
/*
* Entry point of the EFI application.
*
* @handle handle of the loaded image
* @systable system table
* @return status code
*/
efi_status_t EFIAPI efi_main(efi_handle_t handle,
struct efi_system_table *systable)
{
struct efi_simple_text_output_protocol *con_out = systable->con_out;
struct efi_boot_services *boottime = systable->boottime;
struct efi_loaded_image *loaded_image;
efi_status_t ret;
efi_uintn_t i;
con_out->output_string(con_out, L"Hello, world!\n");
/* 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\n");
goto out;
}
/* Find configuration tables */
for (i = 0; i < systable->nr_tables; ++i) {
if (!hw_memcmp(&systable->tables[i].guid, &fdt_guid,
sizeof(efi_guid_t)))
con_out->output_string(con_out, L"Have device tree\n");
if (!hw_memcmp(&systable->tables[i].guid, &smbios_guid,
sizeof(efi_guid_t)))
con_out->output_string(con_out, L"Have SMBIOS table\n");
}
/* 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"\n");
out:
boottime->exit(handle, ret, 0, NULL);
/* We should never arrive here */
return ret;
}