diff options
Diffstat (limited to 'src/sd-boot/stub.c')
| -rw-r--r-- | src/sd-boot/stub.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/sd-boot/stub.c b/src/sd-boot/stub.c new file mode 100644 index 0000000000..e18faac669 --- /dev/null +++ b/src/sd-boot/stub.c @@ -0,0 +1,106 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/* This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * Copyright (C) 2015 Kay Sievers <kay@vrfy.org> + */ + +#include <efi.h> +#include <efilib.h> + +#include "util.h" +#include "pefile.h" +#include "linux.h" + +/* magic string to find in the binary image */ +static const char __attribute__((used)) magic[] = "#### LoaderInfo: stub " 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; + EFI_FILE *root_dir; + CHAR16 *loaded_image_path; + CHAR8 *b; + UINTN size; + BOOLEAN secure = FALSE; + CHAR8 *sections[] = { + (UINT8 *)".cmdline", + (UINT8 *)".linux", + (UINT8 *)".initrd", + NULL + }; + UINTN addrs[ELEMENTSOF(sections)-1] = {}; + UINTN offs[ELEMENTSOF(sections)-1] = {}; + UINTN szs[ELEMENTSOF(sections)-1] = {}; + CHAR8 *cmdline = NULL; + UINTN cmdline_len; + 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; + } + + root_dir = LibOpenRoot(loaded_image->DeviceHandle); + if (!root_dir) { + Print(L"Unable to open root directory: %r ", err); + uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000); + return EFI_LOAD_ERROR; + } + + loaded_image_path = DevicePathToStr(loaded_image->FilePath); + + if (efivar_get_raw(&global_guid, L"SecureBoot", &b, &size) == EFI_SUCCESS) { + if (*b > 0) + secure = TRUE; + FreePool(b); + } + + err = pefile_locate_sections(root_dir, loaded_image_path, 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 *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; + } + + err = linux_exec(image, cmdline, cmdline_len, + (UINTN)loaded_image->ImageBase + addrs[1], + (UINTN)loaded_image->ImageBase + addrs[2], szs[2]); + + Print(L"Execution of embedded linux image failed: %r\n", err); + uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000); + return err; +} |