Commit Graph

4 Commits

Author SHA1 Message Date
Heinrich Schuchardt
b6f11098c9 efi_loader: move EFI_LOAD_FILE2_PROTOCOL_GUID
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>
2020-12-10 09:15:32 +01:00
Heinrich Schuchardt
e2aff337ed efi_loader: illegal free in EFI_LOAD_FILE2_PROTOCOL
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>
2020-10-06 07:43:56 +02:00
Heinrich Schuchardt
5cd28e1760 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 <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2020-10-06 07:43:56 +02:00
Ilias Apalodimas
ec80b4735a efi_loader: Implement FileLoad2 for initramfs loading
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>
2020-02-28 19:37:14 +01:00