From 2e0f3ac758da99fb6d1b4c651643999d83cd0a7f Mon Sep 17 00:00:00 2001 From: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Date: Mon, 12 Aug 2019 23:50:42 +0200 Subject: firmware: do not use relocated _boot_status before it is valid When OpenSBI is started from an address not equal to the link address, it is first relocated to the link address. Hart 0 performs the relocation and notifies the other harts of its completion with the _boot_status variable. It uses the copy of the variable relative to the link address. This copy contains valid data only after relocation has finished. The waiting harts will therefore read invalid data until relocation has finished. This can cause them to continue execution too early. Fix this by using the _boot_status variable relative to the load address while OpenSBI has not finished relocation. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> --- firmware/fw_base.S | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'firmware') diff --git a/firmware/fw_base.S b/firmware/fw_base.S index f2b1ee0..f596638 100644 --- a/firmware/fw_base.S +++ b/firmware/fw_base.S @@ -111,8 +111,6 @@ _wait_relocate_copy_done: REG_L t1, 0(t1) beq t0, t1, _wait_for_boot_hart la t2, _boot_status - sub t2, t2, t0 - add t2, t2, t1 la t3, _wait_for_boot_hart sub t3, t3, t0 add t3, t3, t1 @@ -128,8 +126,17 @@ _wait_relocate_copy_done: jr t3 _relocate_done: - /* mark relocate copy done */ + /* + * Mark relocate copy done + * Use _boot_status copy relative to the load address + */ la t0, _boot_status + la t1, _link_start + REG_L t1, 0(t1) + la t2, _load_start + REG_L t2, 0(t2) + sub t0, t0, t1 + add t0, t0, t2 li t1, BOOT_STATUS_RELOCATE_DONE REG_S t1, 0(t0) fence rw, rw -- cgit v1.2.3