summaryrefslogtreecommitdiff
path: root/lib/efi_loader/efi_load_initrd.c
AgeCommit message (Collapse)Author
2021-03-25efi_loader: Replace config option for initrd loadingIlias Apalodimas
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 defining a UEFI BootXXXX we can use the filepathlist and store a file path pointing to our initrd. Specifically the EFI spec describes: "The first element of the array is a device path that describes the device and location of the Image for this load option. Other device paths may optionally exist in the FilePathList, but their usage is OSV specific" When the EFI application is launched through the bootmgr, we'll try to interpret the extra device path. If that points to a file that exists on our disk, we'll now install the load_file2 and the efi-stub will be able to use it. 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. Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-12-31efi_loader: Remove unused headers from efi_load_initrd.cIlias Apalodimas
dm.h and env.h serve no purpose here. Remove them and sort the remaining in alphabetical order. Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-12-10efi_loader: move EFI_LOAD_FILE2_PROTOCOL_GUIDHeinrich Schuchardt
The EFI_LOAD_FILE_PROTOCOL_GUID and EFI_LOAD_FILE2_PROTOCOL_GUID are needed to complement the implementation of the LoadFile() boot service. Remove a duplicate declaration of a variable for the EFI_LOAD_FILE2_PROTOCOL_GUID. Move the remaining declaration to efi_boottime.c. Add a variable for the EFI_LOAD_FILE_PROTOCOL_GUID. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-10-06efi_loader: illegal free in EFI_LOAD_FILE2_PROTOCOLHeinrich Schuchardt
strsep() changes the address that its first argument points to. We cannot use the changed address as argument of free(). Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2020-10-06efi_loader: description EFI_LOAD_FILE2_PROTOCOLHeinrich Schuchardt
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 <xypron.glpk@gmx.de> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2020-02-28efi_loader: Implement FileLoad2 for initramfs loadingIlias Apalodimas
Following kernel's proposal for an arch-agnostic initrd loading mechanism [1] let's implement the U-boot counterpart. This new approach has a number of advantages compared to what we did up to now. The file is loaded into memory only when requested limiting the area of TOCTOU attacks. Users will be allowed to place the initramfs file on any u-boot accessible partition instead of just the ESP one. Finally this is an attempt of a generic interface across architectures in the linux kernel so it makes sense to support that. The file location is intentionally only supported as a config option argument(CONFIG_EFI_INITRD_FILESPEC), in an effort to enhance security. Although U-boot is not responsible for verifying the integrity of the initramfs, we can enhance the offered security by only accepting a built-in option, which will be naturally verified by UEFI Secure Boot. This can easily change in the future if needed and configure that via ENV or UEFI variable. [1] https://lore.kernel.org/linux-efi/20200207202637.GA3464906@rani.riverdale.lan/T/#m4a25eb33112fab7a22faa0fd65d4d663209af32f Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>