tree f5e085ff9b398092cc48a0afb0e77336441bc9ec
parent 787977c3afe9d951a088a1f12959b00d8343a18d
author Andre Przywara <andre.przywara@arm.com> 1744719880 +0100
committer Govindraj Raja <govindraj.raja@arm.com> 1745590086 +0200

fix(cpufeat): replace "bti" mnemonic with hint instructions

Older GNU binutils version require to specify at least "armv8.5-a" for
the ARM architecture revision to accept "bti" instructions in the
assembly code. Binutils v2.35 have relaxed this, since "bti" is in the
hint space, so is ignored on older cores and does NOT require a BTI
enabled core to execute.

To not exclude those older binutils versions (as shipped with Ubuntu
20.04), use the "hint" encoding for the "bti" instructions, which are
accepted regardless of the minimum architecture revision. Hide this
encoding in a macro, to make the "bti" usage more readable in the
source code.

Change-Id: I005586efd8974a3f2c7202896c881bb5fed07eea
Signed-off-by: Andre Przywara <andre.przywara@arm.com>