Booting from a short-form device path which starts with the first element being a File Path Media Device Path failed because it doesn't contain any valid device with simple file system protocol and efi_dp_find_obj() in efi_load_image_from_path() will return NULL. For instance, /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(0,0)/\helloworld.efi -> shortened version: /\helloworld.efi
With this patch applied, all the media devices with simple file system protocol are enumerated and the boot manager attempts to boot temporarily generated device paths one-by-one.
This new implementation is still a bit incompatible with the UEFI specification in terms of: * not creating real boot options * not distinguishing removable media and fix media (See section 3.1.3 "Boot Options".)
But it still gives us a closer and better solution than the current.
Fixes: commit 9cdf470274ff ("efi_loader: support booting via short-form device-path") Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- include/efi_loader.h | 3 ++ lib/efi_loader/efi_boottime.c | 87 +++++++++++++++++++++++++++++++---- lib/efi_loader/efi_file.c | 35 ++++++++++---- 3 files changed, 107 insertions(+), 18 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h index ba79a9afb404..9730c1375a55 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -661,6 +661,9 @@ void efi_signal_event(struct efi_event *event); struct efi_simple_file_system_protocol *efi_simple_file_system( struct blk_desc *desc, int part, struct efi_device_path *dp);
+/* open file from simple file system */ +struct efi_file_handle *efi_file_from_fs(struct efi_simple_file_system_protocol *v, + struct efi_device_path *fp); /* open file from device-path: */ struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp);
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index 5bcb8253edba..39b0e8f7ade0 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -1868,19 +1868,21 @@ out: }
/** - * efi_load_image_from_file() - load an image from file system + * __efi_load_image_from_file() - load an image from file system * * Read a file into a buffer allocated as EFI_BOOT_SERVICES_DATA. It is the * callers obligation to update the memory type as needed. * + * @v: simple file system * @file_path: the path of the image to load * @buffer: buffer containing the loaded image * @size: size of the loaded image * Return: status code */ static -efi_status_t efi_load_image_from_file(struct efi_device_path *file_path, - void **buffer, efi_uintn_t *size) +efi_status_t __efi_load_image_from_file(struct efi_simple_file_system_protocol *v, + struct efi_device_path *file_path, + void **buffer, efi_uintn_t *size) { struct efi_file_handle *f; efi_status_t ret; @@ -1888,7 +1890,11 @@ efi_status_t efi_load_image_from_file(struct efi_device_path *file_path, efi_uintn_t bs;
/* Open file */ - f = efi_file_from_path(file_path); + if (v) + f = efi_file_from_fs(v, file_path); + else + /* file_path should have a device path */ + f = efi_file_from_path(file_path); if (!f) return EFI_NOT_FOUND;
@@ -1921,6 +1927,64 @@ error: return ret; }
+/** + * efi_load_image_from_file() - load an image from file system + * + * Read a file into a buffer allocated as EFI_BOOT_SERVICES_DATA. It is the + * callers obligation to update the memory type as needed. + * + * @file_path: the path of the image to load + * @buffer: buffer containing the loaded image + * @size: size of the loaded image + * Return: status code + */ +static +efi_status_t efi_load_image_from_file(struct efi_device_path *file_path, + void **buffer, efi_uintn_t *size) +{ + efi_uintn_t no_handles; + efi_handle_t *handles; + struct efi_handler *handler; + struct efi_simple_file_system_protocol *fs; + int i; + efi_status_t ret; + + /* if a file_path contains a device path */ + if (!EFI_DP_TYPE(file_path, MEDIA_DEVICE, FILE_PATH)) + return __efi_load_image_from_file(NULL, file_path, buffer, size); + + /* no explicit device specified */ + ret = EFI_CALL(efi_locate_handle_buffer( + BY_PROTOCOL, + &efi_simple_file_system_protocol_guid, + NULL, + &no_handles, + &handles)); + if (ret != EFI_SUCCESS) + return ret; + if (!no_handles) + return EFI_NOT_FOUND; + + for (i = 0; i < no_handles; i++) { + ret = efi_search_protocol(handles[i], + &efi_simple_file_system_protocol_guid, + &handler); + if (ret != EFI_SUCCESS) + /* unlikely */ + continue; + + fs = handler->protocol_interface; + if (!fs) + continue; + + ret = __efi_load_image_from_file(fs, file_path, buffer, size); + if (ret == EFI_SUCCESS) + return ret; + } + + return EFI_NOT_FOUND; +} + /** * efi_load_image_from_path() - load an image using a file path * @@ -1940,7 +2004,7 @@ efi_status_t efi_load_image_from_path(bool boot_policy, { efi_handle_t device; efi_status_t ret; - struct efi_device_path *dp, *rem; + struct efi_device_path *rem; struct efi_load_file_protocol *load_file_protocol = NULL; efi_uintn_t buffer_size; uint64_t addr, pages; @@ -1950,12 +2014,15 @@ efi_status_t efi_load_image_from_path(bool boot_policy, *buffer = NULL; *size = 0;
- dp = file_path; - device = efi_dp_find_obj(dp, NULL, &rem); - ret = efi_search_protocol(device, &efi_simple_file_system_protocol_guid, - NULL); + /* try first for simple file system protocols */ + ret = efi_load_image_from_file(file_path, buffer, size); if (ret == EFI_SUCCESS) - return efi_load_image_from_file(file_path, buffer, size); + return ret; + + /* TODO: does this really make sense? */ + device = efi_dp_find_obj(file_path, NULL, &rem); + if (!device) + return EFI_NOT_FOUND;
ret = efi_search_protocol(device, &efi_guid_load_file_protocol, NULL); if (ret == EFI_SUCCESS) { diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c index 7a7077e6d032..2d6a432b168b 100644 --- a/lib/efi_loader/efi_file.c +++ b/lib/efi_loader/efi_file.c @@ -1083,16 +1083,16 @@ static const struct efi_file_handle efi_file_handle_protocol = { /** * efi_file_from_path() - open file via device path * - * @fp: device path + * @v: simple file system + * @fp: file path * Return: EFI_FILE_PROTOCOL for the file or NULL */ -struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp) +struct efi_file_handle *efi_file_from_fs(struct efi_simple_file_system_protocol *v, + struct efi_device_path *fp) { - struct efi_simple_file_system_protocol *v; struct efi_file_handle *f; efi_status_t ret;
- v = efi_fs_from_path(fp); if (!v) return NULL;
@@ -1100,10 +1100,6 @@ struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp) if (ret != EFI_SUCCESS) return NULL;
- /* Skip over device-path nodes before the file path. */ - while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) - fp = efi_dp_next(fp); - /* * Step through the nodes of the directory path until the actual file * node is reached which is the final node in the device path. @@ -1138,6 +1134,29 @@ struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp) return f; }
+/** + * efi_file_from_path() - open file via device path + * + * @fp: device path + * Return: EFI_FILE_PROTOCOL for the file or NULL + */ +struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp) +{ + struct efi_simple_file_system_protocol *v; + + v = efi_fs_from_path(fp); + if (!v) + return NULL; + + /* Skip over device-path nodes before the file path. */ + while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) + fp = efi_dp_next(fp); + if (!fp) + return NULL; + + return efi_file_from_fs(v, fp); +} + static efi_status_t EFIAPI efi_open_volume(struct efi_simple_file_system_protocol *this, struct efi_file_handle **root)