From 5cd28e17600458ee99e69a86856f2b7e8eddd0c0 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 3 Oct 2020 12:44:31 +0200 Subject: [PATCH] efi_loader: description EFI_LOAD_FILE2_PROTOCOL U-Boot offers a EFI_LOAD_FILE2_PROTOCOL which the Linux EFI stub can use to load an initial RAM disk. Update the function comments of the implementation. Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas --- lib/efi_loader/efi_load_initrd.c | 42 ++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 19 deletions(-) diff --git a/lib/efi_loader/efi_load_initrd.c b/lib/efi_loader/efi_load_initrd.c index 574a83d..ff69e6e 100644 --- a/lib/efi_loader/efi_load_initrd.c +++ b/lib/efi_loader/efi_load_initrd.c @@ -47,9 +47,9 @@ static const struct efi_initrd_dp dp = { /** * get_file_size() - retrieve the size of initramfs, set efi status on error * - * @dev: device to read from. i.e "mmc" - * @part: device partition. i.e "0:1" - * @file: name fo file + * @dev: device to read from, e.g. "mmc" + * @part: device partition, e.g. "0:1" + * @file: name of file * @status: EFI exit code in case of failure * * Return: size of file @@ -78,15 +78,16 @@ out: } /** - * load_file2() - get information about random number generation + * efi_load_file2initrd() - load initial RAM disk + * + * This function implements the LoadFile service of the EFI_LOAD_FILE2_PROTOCOL + * in order to load an initial RAM disk requested by the Linux kernel stub. * - * This function implement the LoadFile2() service in order to load an initram - * disk requested by the Linux kernel stub. * See the UEFI spec for details. * - * @this: loadfile2 protocol instance - * @file_path: relative path of the file. "" in this case - * @boot_policy: must be false for Loadfile2 + * @this: EFI_LOAD_FILE2_PROTOCOL instance + * @file_path: media device path of the file, "" in this case + * @boot_policy: must be false * @buffer_size: size of allocated buffer * @buffer: buffer to load the file * @@ -128,7 +129,13 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this, goto out; } - /* expect something like 'mmc 0:1 initrd.cpio.gz' */ + /* + * expect a string with three space separated parts: + * + * * a block device type, e.g. "mmc" + * * a device and partition identifier, e.g. "0:1" + * * a file path on the block device, e.g. "/boot/initrd.cpio.gz" + */ dev = strsep(&s, " "); if (!dev) goto out; @@ -168,23 +175,20 @@ out: } /** - * efi_initrd_register() - Register a handle and loadfile2 protocol + * efi_initrd_register() - create handle for loading initial RAM disk * - * This function creates a new handle and installs a linux specific GUID - * to handle initram disk loading during boot. - * See the UEFI spec for details. + * This function creates a new handle and installs a Linux specific vendor + * device path and an EFI_LOAD_FILE_2_PROTOCOL. Linux uses the device path + * to identify the handle and then calls the LoadFile service of the + * EFI_LOAD_FILE_2_PROTOCOL to read the initial RAM disk. * - * Return: status code + * Return: status code */ efi_status_t efi_initrd_register(void) { efi_handle_t efi_initrd_handle = NULL; efi_status_t ret; - /* - * Set up the handle with the EFI_LOAD_FILE2_PROTOCOL which Linux may - * use to load the initial ramdisk. - */ ret = EFI_CALL(efi_install_multiple_protocol_interfaces (&efi_initrd_handle, /* initramfs */ -- 2.7.4