On Wed, Dec 30, 2020 at 05:07:18PM +0200, Ilias Apalodimas wrote:
> Up to now we install EFI_LOAD_FILE2_PROTOCOL to load an initrd
> unconditionally. Although we correctly return various EFI exit codes
> depending on the file status (i.e EFI_NO_MEDIA, EFI_NOT_FOUND etc), the
> kernel loader, only falls back to the cmdline interpreted initrd if the
> protocol is not installed.
>
> This creates a problem for EFI installers, since they won't be able to
> load their own initrd and continue the installation. It also makes the
> feature hard to use, since we can either have a single initrd or we have
> to recompile u-boot if the filename changes.
>
> So let's introduce a different logic that will decouple the initrd
> path from the config option we currently have.
> When the EFI application is launched through the bootmgr, we'll try to
> match the BootCurrent value to an Initrd#### EFI variable.
> e.g Boot0000 -> Initrd0000, Boot0010 -> Initrd0010 etc.
Do you think this semantics be kept U-boot specific?
It seems that it can work for any other EFI firmware (implementation).
> The Initrd#### EFI variable is expected to include the full file path,
> i.e 'mmc 0:1 initrd'. If the file is found, we'll install the
If so, the content of "Initrd####" should contain a generic EFI
representation of file path.
Please note that "Boot####" internally contains a flattened string of
"EFI device path" to the image while efidebug command accepts a style of
"mmc 0:1 image" as arguments to "efidebug boot add" sub-command.
-Takahiro Akashi
> appropriate protocol so the kernel's efi-stub can use it and load our
> initrd. If the file is not found the kernel will still try to load an
> initrd parsing the kernel cmdline, since the protocol won't be installed.
>
> This opens up another path using U-Boot and defines a new boot flow.
> A user will be able to control the kernel/initrd pairs without explicit
> cmdline args or GRUB. So we can base the whole boot flow on the Boot####
> and Initrd#### paired values.
>
> Suggested-by: Heinrich Schuchardt <xypron.g...@gmx.de>
> Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> ---
> cmd/bootefi.c | 13 +++++
> include/efi_loader.h | 2 +-
> lib/efi_loader/Kconfig | 13 ++---
> lib/efi_loader/efi_load_initrd.c | 93 ++++++++++----------------------
> 4 files changed, 46 insertions(+), 75 deletions(-)
>
> diff --git a/cmd/bootefi.c b/cmd/bootefi.c
> index fdf909f8da2c..0234b0df2258 100644
> --- a/cmd/bootefi.c
> +++ b/cmd/bootefi.c
> @@ -377,6 +377,19 @@ static int do_efibootmgr(void)
> return CMD_RET_FAILURE;
> }
>
> + /* efi_exit() will delete all protocols and the handle itself on exit */
> + if (IS_ENABLED(CONFIG_EFI_LOAD_FILE2_INITRD)) {
> + ret = efi_initrd_register(&handle);
> + /* Just warn the user. If the installation fails, the kernel
> + * either load an initrd specificied in the cmdline or fail
> + * to boot.
> + * If we decide to fail the command here we need to uninstall
> + * the protocols efi_bootmgr_load() installed
> + */
> + if (ret != EFI_SUCCESS)
> + log_warning("EFI boot manager: Failed to install
> Loadfile2 for initrd\n");
> + }
> +
> ret = do_bootefi_exec(handle, load_options);
>
> if (ret != EFI_SUCCESS)
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index af30dbafab77..000cc942e31c 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -422,7 +422,7 @@ efi_status_t efi_gop_register(void);
> efi_status_t efi_net_register(void);
> /* Called by bootefi to make the watchdog available */
> efi_status_t efi_watchdog_register(void);
> -efi_status_t efi_initrd_register(void);
> +efi_status_t efi_initrd_register(efi_handle_t *initrd_handle);
> /* Called by bootefi to make SMBIOS tables available */
> /**
> * efi_acpi_register() - write out ACPI tables
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index dd8b93bd3c5a..96b5934a221d 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -212,14 +212,11 @@ config EFI_LOAD_FILE2_INITRD
> help
> Expose a EFI_FILE_LOAD2_PROTOCOL that the Linux UEFI stub can
> use to load the initial ramdisk. Once this is enabled using
> - initrd=<ramdisk> will stop working.
> -
> -config EFI_INITRD_FILESPEC
> - string "initramfs path"
> - default "host 0:1 initrd"
> - depends on EFI_LOAD_FILE2_INITRD
> - help
> - Full path of the initramfs file, e.g. mmc 0:2 initramfs.cpio.gz.
> + initrd=<ramdisk> will stop working. The protocol will only be
> + installed if bootmgr is used and the file is found on the defined
> + path. A boot entry of Boot0001 will try to match Initrd0001 and use
> + it. Initrd EFI variable format should be '<dev> <part> <filename>'
> + i.e 'mmc 0:1 boot/initrd'
>
> config EFI_SECURE_BOOT
> bool "Enable EFI secure boot support"
> diff --git a/lib/efi_loader/efi_load_initrd.c
> b/lib/efi_loader/efi_load_initrd.c
> index 4ec55d70979d..6289957c97bc 100644
> --- a/lib/efi_loader/efi_load_initrd.c
> +++ b/lib/efi_loader/efi_load_initrd.c
> @@ -5,7 +5,9 @@
>
> #include <common.h>
> #include <efi_loader.h>
> +#include <efi_helper.h>
> #include <efi_load_initrd.h>
> +#include <efi_variable.h>
> #include <fs.h>
> #include <malloc.h>
> #include <mapmem.h>
> @@ -43,40 +45,7 @@ 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, 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
> - */
> -static loff_t get_file_size(const char *dev, const char *part, const char
> *file,
> - efi_status_t *status)
> -{
> - loff_t sz = 0;
> - int ret;
> -
> - ret = fs_set_blk_dev(dev, part, FS_TYPE_ANY);
> - if (ret) {
> - *status = EFI_NO_MEDIA;
> - goto out;
> - }
> -
> - ret = fs_size(file, &sz);
> - if (ret) {
> - sz = 0;
> - *status = EFI_NOT_FOUND;
> - goto out;
> - }
> -
> -out:
> - return sz;
> -}
> -
> -/**
> - * efi_load_file2initrd() - load initial RAM disk
> + * efi_load_file2_initrd() - 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.
> @@ -96,21 +65,15 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this,
> struct efi_device_path *file_path, bool boot_policy,
> efi_uintn_t *buffer_size, void *buffer)
> {
> - char *filespec;
> efi_status_t status = EFI_NOT_FOUND;
> loff_t file_sz = 0, read_sz = 0;
> - char *dev, *part, *file;
> - char *pos;
> int ret;
> + struct load_file_info info;
> + char initrd[] = "Initrd";
>
> EFI_ENTRY("%p, %p, %d, %p, %p", this, file_path, boot_policy,
> buffer_size, buffer);
>
> - filespec = strdup(CONFIG_EFI_INITRD_FILESPEC);
> - if (!filespec)
> - goto out;
> - pos = filespec;
> -
> if (!this || this != &efi_lf2_protocol ||
> !buffer_size) {
> status = EFI_INVALID_PARAMETER;
> @@ -128,24 +91,11 @@ efi_load_file2_initrd(struct efi_load_file_protocol
> *this,
> goto out;
> }
>
> - /*
> - * 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(&pos, " ");
> - if (!dev)
> - goto out;
> - part = strsep(&pos, " ");
> - if (!part)
> - goto out;
> - file = strsep(&pos, " ");
> - if (!file)
> + status = efi_get_fp_from_var(initrd, &info);
> + if (status != EFI_SUCCESS)
> goto out;
>
> - file_sz = get_file_size(dev, part, file, &status);
> + file_sz = get_file_size(&info, &status);
> if (!file_sz)
> goto out;
>
> @@ -153,23 +103,25 @@ efi_load_file2_initrd(struct efi_load_file_protocol
> *this,
> status = EFI_BUFFER_TOO_SMALL;
> *buffer_size = file_sz;
> } else {
> - ret = fs_set_blk_dev(dev, part, FS_TYPE_ANY);
> + ret = fs_set_blk_dev(info.dev, info.part,
> + FS_TYPE_ANY);
> if (ret) {
> status = EFI_NO_MEDIA;
> goto out;
> }
>
> - ret = fs_read(file, map_to_sysmem(buffer), 0, *buffer_size,
> - &read_sz);
> - if (ret || read_sz != file_sz)
> + ret = fs_read(info.filename, map_to_sysmem(buffer), 0,
> + *buffer_size, &read_sz);
> + if (ret || read_sz != file_sz) {
> + status = EFI_DEVICE_ERROR;
> goto out;
> + }
> *buffer_size = read_sz;
>
> status = EFI_SUCCESS;
> }
>
> out:
> - free(filespec);
> return EFI_EXIT(status);
> }
>
> @@ -183,13 +135,22 @@ out:
> *
> * Return: status code
> */
> -efi_status_t efi_initrd_register(void)
> +efi_status_t efi_initrd_register(efi_handle_t *efi_initrd_handle)
> {
> - efi_handle_t efi_initrd_handle = NULL;
> efi_status_t ret;
> + struct load_file_info info;
> + char initrd[] = "Initrd";
> +
> + ret = efi_get_fp_from_var(initrd, &info);
> + /*
> + * Don't fail here. If we don't install the protocol the efi-stub will
> + * try to load and initrd parsing the kernel cmdline
> + */
> + if (ret != EFI_SUCCESS)
> + return EFI_SUCCESS;
>
> ret = EFI_CALL(efi_install_multiple_protocol_interfaces
> - (&efi_initrd_handle,
> + (efi_initrd_handle,
> /* initramfs */
> &efi_guid_device_path, &dp,
> /* LOAD_FILE2 */
> --
> 2.30.0
>
