src/boot/efi/stub.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /* This program is free software; you can redistribute it and/or modify it
   3  * under the terms of the GNU Lesser General Public License as published by
   4  * the Free Software Foundation; either version 2.1 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful, but
   8  * WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10  * Lesser General Public License for more details.
  11  *
  12  * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
  13  */
  14
  15 #include <efi.h>
  16 #include <efilib.h>
  17
  18 #include "disk.h"
  19 #include "graphics.h"
  20 #include "linux.h"
  21 #include "measure.h"
  22 #include "pe.h"
  23 #include "splash.h"
  24 #include "util.h"
  25
  26 /* magic string to find in the binary image */
  27 static const char __attribute__((used)) magic[] = "#### LoaderInfo: systemd-stub " PACKAGE_VERSION " ####";
  28
  29 static const EFI_GUID global_guid = EFI_GLOBAL_VARIABLE;
  30
  31 EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
  32         EFI_LOADED_IMAGE *loaded_image;
  33         _cleanup_freepool_ CHAR8 *b = NULL;
  34         UINTN size;
  35         BOOLEAN secure = FALSE;
  36         CHAR8 *sections[] = {
  37                 (UINT8 *)".cmdline",
  38                 (UINT8 *)".linux",
  39                 (UINT8 *)".initrd",
  40                 (UINT8 *)".splash",
  41                 NULL
  42         };
  43         UINTN addrs[ELEMENTSOF(sections)-1] = {};
  44         UINTN offs[ELEMENTSOF(sections)-1] = {};
  45         UINTN szs[ELEMENTSOF(sections)-1] = {};
  46         CHAR8 *cmdline = NULL;
  47         UINTN cmdline_len;
  48         CHAR16 uuid[37];
  49         EFI_STATUS err;
  50
  51         InitializeLib(image, sys_table);
  52
  53         err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (VOID **)&loaded_image,
  54                                 image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
  55         if (EFI_ERROR(err)) {
  56                 Print(L"Error getting a LoadedImageProtocol handle: %r ", err);
  57                 uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
  58                 return err;
  59         }
  60
  61         if (efivar_get_raw(&global_guid, L"SecureBoot", &b, &size) == EFI_SUCCESS)
  62                 if (*b > 0)
  63                         secure = TRUE;
  64
  65         err = pe_memory_locate_sections(loaded_image->ImageBase, sections, addrs, offs, szs);
  66         if (EFI_ERROR(err)) {
  67                 Print(L"Unable to locate embedded .linux section: %r ", err);
  68                 uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
  69                 return err;
  70         }
  71
  72         if (szs[0] > 0)
  73                 cmdline = (CHAR8 *)(loaded_image->ImageBase + addrs[0]);
  74
  75         cmdline_len = szs[0];
  76
  77         /* if we are not in secure boot mode, accept a custom command line and replace the built-in one */
  78         if (!secure && loaded_image->LoadOptionsSize > 0 && *(CHAR16 *)loaded_image->LoadOptions != 0) {
  79                 CHAR16 *options;
  80                 CHAR8 *line;
  81                 UINTN i;
  82
  83                 options = (CHAR16 *)loaded_image->LoadOptions;
  84                 cmdline_len = (loaded_image->LoadOptionsSize / sizeof(CHAR16)) * sizeof(CHAR8);
  85                 line = AllocatePool(cmdline_len);
  86                 for (i = 0; i < cmdline_len; i++)
  87                         line[i] = options[i];
  88                 cmdline = line;
  89
  90 #if ENABLE_TPM
  91                 /* Try to log any options to the TPM, especially manually edited options */
  92                 err = tpm_log_event(SD_TPM_PCR,
  93                                     (EFI_PHYSICAL_ADDRESS) (UINTN) loaded_image->LoadOptions,
  94                                     loaded_image->LoadOptionsSize, loaded_image->LoadOptions);
  95                 if (EFI_ERROR(err)) {
  96                         Print(L"Unable to add image options measurement: %r", err);
  97                         uefi_call_wrapper(BS->Stall, 1, 200 * 1000);
  98                 }
  99 #endif
 100         }
 101
 102         /* export the device path this image is started from */
 103         if (disk_get_part_uuid(loaded_image->DeviceHandle, uuid) == EFI_SUCCESS)
 104                 efivar_set(L"LoaderDevicePartUUID", uuid, FALSE);
 105
 106         /* if LoaderImageIdentifier is not set, assume the image with this stub was loaded directly from UEFI */
 107         if (efivar_get_raw(&global_guid, L"LoaderImageIdentifier", &b, &size) != EFI_SUCCESS) {
 108                 _cleanup_freepool_ CHAR16 *s;
 109
 110                 s = DevicePathToStr(loaded_image->FilePath);
 111                 efivar_set(L"LoaderImageIdentifier", s, FALSE);
 112         }
 113
 114         /* if LoaderFirmwareInfo is not set, let's set it */
 115         if (efivar_get_raw(&global_guid, L"LoaderFirmwareInfo", &b, &size) != EFI_SUCCESS) {
 116                 _cleanup_freepool_ CHAR16 *s;
 117
 118                 s = PoolPrint(L"%s %d.%02d", ST->FirmwareVendor, ST->FirmwareRevision >> 16, ST->FirmwareRevision & 0xffff);
 119                 efivar_set(L"LoaderFirmwareInfo", s, FALSE);
 120         }
 121
 122         /* ditto for LoaderFirmwareType */
 123         if (efivar_get_raw(&global_guid, L"LoaderFirmwareType", &b, &size) != EFI_SUCCESS) {
 124                 _cleanup_freepool_ CHAR16 *s;
 125
 126                 s = PoolPrint(L"UEFI %d.%02d", ST->Hdr.Revision >> 16, ST->Hdr.Revision & 0xffff);
 127                 efivar_set(L"LoaderFirmwareType", s, FALSE);
 128         }
 129
 130         /* add StubInfo */
 131         if (efivar_get_raw(&global_guid, L"StubInfo", &b, &size) != EFI_SUCCESS)
 132                 efivar_set(L"StubInfo", L"systemd-stub " PACKAGE_VERSION, FALSE);
 133
 134         if (szs[3] > 0)
 135                 graphics_splash((UINT8 *)((UINTN)loaded_image->ImageBase + addrs[3]), szs[3], NULL);
 136
 137         err = linux_exec(image, cmdline, cmdline_len,
 138                          (UINTN)loaded_image->ImageBase + addrs[1],
 139                          (UINTN)loaded_image->ImageBase + addrs[2], szs[2], secure);
 140
 141         graphics_mode(FALSE);
 142         Print(L"Execution of embedded linux image failed: %r\n", err);
 143         uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
 144         return err;
 145 }