tree c37dc66dde13d4911c6bb1089eb90d6bee072aa0
parent 8e9d17251ba89fb7227ae4c7cb2c1611c2a10eac
author Lukas Auer <lukas.auer@aisec.fraunhofer.de> 1575844129 +0100
committer Andes <uboot@andestech.com> 1575937390 +0800

spl: opensbi: specify main hart as preferred boot hart

OpenSBI uses a relocation lottery to determine the hart to relocate
OpenSBI to its link address. In the U-Boot SPL boot flow, the main hart
schedules the secondary harts to enter OpenSBI before doing so itself.
One of the secondary harts will therefore always be the winner of the
relocation lottery. This is problematic if the link address ranges of
OpenSBI and U-Boot SPL overlap. OpenSBI will be relocated and therefore
overwrite U-Boot SPL while some harts may still run it, leading to code
corruption.

Avoid this problem by specifying the main hart as the preferred boot
hart to perform the OpenSBI relocation. The main hart will be the last
hart to enter OpenSBI, relocation can therefore occur safely.

The boot hart field was added to version 2 of the OpenSBI FW_DYNAMIC
info structure. The header file include/opensbi.h is synchronized with
include/sbi/fw_dynamic.h from the OpenSBI project to update the info
structure. The header file is recent as of commit
7a13beb21326 ("firmware: Add preferred boot HART field in struct
fw_dynamic_info").

Reported-by: Rick Chen <rick@andestech.com>
Suggested-by: Anup Patel <Anup.Patel@wdc.com>
Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Rick Chen <rick@andestech.com>
Tested-by: Rick Chen <rick@andestech.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>