summaryrefslogtreecommitdiff
path: root/src/boot/efi/stub.c
blob: 6b07879971c5dbebd84b5739d1bcd1d016f36142 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/* SPDX-License-Identifier: LGPL-2.1+ */

#include <efi.h>
#include <efilib.h>

#include "disk.h"
#include "graphics.h"
#include "linux.h"
#include "measure.h"
#include "pe.h"
#include "splash.h"
#include "util.h"

/* magic string to find in the binary image */
static const char __attribute__((used)) magic[] = "#### LoaderInfo: systemd-stub " GIT_VERSION " ####";

static const EFI_GUID global_guid = EFI_GLOBAL_VARIABLE;

EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
        EFI_LOADED_IMAGE *loaded_image;
        _cleanup_freepool_ CHAR8 *b = NULL;
        UINTN size;
        BOOLEAN secure = FALSE;
        CHAR8 *sections[] = {
                (UINT8 *)".cmdline",
                (UINT8 *)".linux",
                (UINT8 *)".initrd",
                (UINT8 *)".splash",
                NULL
        };
        UINTN addrs[ELEMENTSOF(sections)-1] = {};
        UINTN offs[ELEMENTSOF(sections)-1] = {};
        UINTN szs[ELEMENTSOF(sections)-1] = {};
        CHAR8 *cmdline = NULL;
        UINTN cmdline_len;
        CHAR16 uuid[37];
        EFI_STATUS err;

        InitializeLib(image, sys_table);

        err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (VOID **)&loaded_image,
                                image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
        if (EFI_ERROR(err)) {
                Print(L"Error getting a LoadedImageProtocol handle: %r ", err);
                uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
                return err;
        }

        if (efivar_get_raw(&global_guid, L"SecureBoot", &b, &size) == EFI_SUCCESS)
                if (*b > 0)
                        secure = TRUE;

        err = pe_memory_locate_sections(loaded_image->ImageBase, sections, addrs, offs, szs);
        if (EFI_ERROR(err)) {
                Print(L"Unable to locate embedded .linux section: %r ", err);
                uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
                return err;
        }

        if (szs[0] > 0)
                cmdline = (CHAR8 *)(loaded_image->ImageBase + addrs[0]);

        cmdline_len = szs[0];

        /* if we are not in secure boot mode, accept a custom command line and replace the built-in one */
        if (!secure && loaded_image->LoadOptionsSize > 0 && *(CHAR16 *)loaded_image->LoadOptions > 0x1F) {
                CHAR16 *options;
                CHAR8 *line;
                UINTN i;

                options = (CHAR16 *)loaded_image->LoadOptions;
                cmdline_len = (loaded_image->LoadOptionsSize / sizeof(CHAR16)) * sizeof(CHAR8);
                line = AllocatePool(cmdline_len);
                for (i = 0; i < cmdline_len; i++)
                        line[i] = options[i];
                cmdline = line;

#if ENABLE_TPM
                /* Try to log any options to the TPM, especially manually edited options */
                err = tpm_log_event(SD_TPM_PCR,
                                    (EFI_PHYSICAL_ADDRESS) (UINTN) loaded_image->LoadOptions,
                                    loaded_image->LoadOptionsSize, loaded_image->LoadOptions);
                if (EFI_ERROR(err)) {
                        Print(L"Unable to add image options measurement: %r", err);
                        uefi_call_wrapper(BS->Stall, 1, 200 * 1000);
                }
#endif
        }

        /* export the device path this image is started from */
        if (disk_get_part_uuid(loaded_image->DeviceHandle, uuid) == EFI_SUCCESS)
                efivar_set(L"LoaderDevicePartUUID", uuid, FALSE);

        /* if LoaderImageIdentifier is not set, assume the image with this stub was loaded directly from UEFI */
        if (efivar_get_raw(&global_guid, L"LoaderImageIdentifier", &b, &size) != EFI_SUCCESS) {
                _cleanup_freepool_ CHAR16 *s;

                s = DevicePathToStr(loaded_image->FilePath);
                efivar_set(L"LoaderImageIdentifier", s, FALSE);
        }

        /* if LoaderFirmwareInfo is not set, let's set it */
        if (efivar_get_raw(&global_guid, L"LoaderFirmwareInfo", &b, &size) != EFI_SUCCESS) {
                _cleanup_freepool_ CHAR16 *s;

                s = PoolPrint(L"%s %d.%02d", ST->FirmwareVendor, ST->FirmwareRevision >> 16, ST->FirmwareRevision & 0xffff);
                efivar_set(L"LoaderFirmwareInfo", s, FALSE);
        }

        /* ditto for LoaderFirmwareType */
        if (efivar_get_raw(&global_guid, L"LoaderFirmwareType", &b, &size) != EFI_SUCCESS) {
                _cleanup_freepool_ CHAR16 *s;

                s = PoolPrint(L"UEFI %d.%02d", ST->Hdr.Revision >> 16, ST->Hdr.Revision & 0xffff);
                efivar_set(L"LoaderFirmwareType", s, FALSE);
        }

        /* add StubInfo */
        if (efivar_get_raw(&global_guid, L"StubInfo", &b, &size) != EFI_SUCCESS)
                efivar_set(L"StubInfo", L"systemd-stub " GIT_VERSION, FALSE);

        if (szs[3] > 0)
                graphics_splash((UINT8 *)((UINTN)loaded_image->ImageBase + addrs[3]), szs[3], NULL);

        err = linux_exec(image, cmdline, cmdline_len,
                         (UINTN)loaded_image->ImageBase + addrs[1],
                         (UINTN)loaded_image->ImageBase + addrs[2], szs[2], secure);

        graphics_mode(FALSE);
        Print(L"Execution of embedded linux image failed: %r\n", err);
        uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
        return err;
}