diff options
Diffstat (limited to 'src/boot/efi/stub.c')
| -rw-r--r-- | src/boot/efi/stub.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/boot/efi/stub.c b/src/boot/efi/stub.c new file mode 100644 index 0000000..6b07879 --- /dev/null +++ b/src/boot/efi/stub.c @@ -0,0 +1,133 @@ +/* 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; +} |