U-Boot, in some occasions, injects a 'kaslr-seed' property on the /chosen
node. That would be problematic in case we want to measure the DTB we
install in the configuration table, since it would change across reboots.
The Linux kernel EFI-stub completely ignores it and only relies on
EFI_RNG_PROTOCOL for it's own randomness needs (i.e the randomization
of the physical placement of the kernel). In fact it (blindly) overwrites
the existing seed if the protocol is installed. However it still uses it
for randomizing it's virtual placement.
So let's get rid of it in the presence of the RNG protocol.
It's worth noting that TPMs also provide an RNG. So if we tweak our
EFI_RNG_PROTOCOL slightly and install the protocol when a TPM device
is present the 'kaslr-seed' property will always be removed, allowing
us to reliably measure our DTB.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
The (yet unreleased version of the) devicetree specification clearly
states that:
As with the /reserved-memory node, when booting via UEFI
entries in the Memory Reservation Block must also be listed
in the system memory map obtained via the GetMemoryMap() toi
protect against allocations by UEFI applications. The memory
reservation block entries should be listed with type
EfiReservedMemoryType.
This restores the behaviour that was changed by commit 4cbb2930bd
("efi_loader: consider no-map property of reserved memory").
Fixes: 4cbb2930bd ("efi_loader: consider no-map property of reserved memory")
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
In the implementation of the EFI_DT_FIXUP_PROTOCOL:
* Only check the buffer size when EFI_DT_APPLY_FIXUPS is set.
* In this case the field totalsize of the device-tree may not exceed the
buffer size.
* Install device-tree only if EFI_DT_INSTALL_TABLE is set.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Move this out of the common header and include it only where needed. In
a number of cases this requires adding "struct udevice;" to avoid adding
another large header or in other cases replacing / adding missing header
files that had been pulled in, very indirectly. Finally, we have a few
cases where we did not need to include <asm/global_data.h> at all, so
remove that include.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
A boot manager like GRUB can use the protocol to
* apply U-Boot's fix-ups to the a device-tree
* let U-Boot make memory reservations according to the device-tree
* install the device-tree as a configuration table
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
