According to EFI 9.3.6.4 File Path Media Device Path, Path Name is A NULL-terminated Path string including directory and file names.
EFI chainloader is using two File Path nodes for image name - directory and file. It appears that at least some firmware implementations interpret NULL terminated directory path as end of full pathname, thus truncating it. OTOH leaving path names non-NULL terminated caused other errors (see commit ce95549cc54b5d6f494608a7c390dba3aab4fba7) Use single File Path node containing both directory and file name to avoid it. See also https://bugzilla.opensuse.org/show_bug.cgi?id=1026344 --- Anyone remembers why we build complete path using two nodes? As far as I can tell no other bootloader does it. I am really uneasy to do it now, but we have known bugs both with and without ce95549cc54b5d6f494608a7c390dba3aab4fba7 and this looks like the most straightforward fix. grub-core/loader/efi/chainloader.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/grub-core/loader/efi/chainloader.c b/grub-core/loader/efi/chainloader.c index adc8563..329dd57 100644 --- a/grub-core/loader/efi/chainloader.c +++ b/grub-core/loader/efi/chainloader.c @@ -158,29 +158,23 @@ make_file_path (grub_efi_device_path_t *dp, const char *filename) d = GRUB_EFI_NEXT_DEVICE_PATH (d); } - /* File Path is NULL terminated. Allocate space for 2 extra characters */ - /* FIXME why we split path in two components? */ + /* File Path is NULL terminated. Allocate space for extra character */ file_path = grub_malloc (size - + ((grub_strlen (dir_start) + 2) + + ((grub_strlen (dir_start) + 1) * GRUB_MAX_UTF16_PER_UTF8 * sizeof (grub_efi_char16_t)) - + sizeof (grub_efi_file_path_device_path_t) * 2); + + sizeof (grub_efi_file_path_device_path_t)); if (! file_path) return 0; grub_memcpy (file_path, dp, size); - /* Fill the file path for the directory. */ + /* Fill the complete file path. */ d = (grub_efi_device_path_t *) ((char *) file_path + ((char *) d - (char *) dp)); grub_efi_print_device_path (d); copy_file_path ((grub_efi_file_path_device_path_t *) d, - dir_start, dir_end - dir_start); - - /* Fill the file path for the file. */ - d = GRUB_EFI_NEXT_DEVICE_PATH (d); - copy_file_path ((grub_efi_file_path_device_path_t *) d, - dir_end + 1, grub_strlen (dir_end + 1)); + dir_start, grub_strlen (dir_start)); /* Fill the end of device path nodes. */ d = GRUB_EFI_NEXT_DEVICE_PATH (d); -- tg: (2fb8cd2..) u/use-single-file-path-in-efi-chainloader (depends on: master) _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
