forked from Mirrors/opensbi
4c112650bb
This patch abstracts out the instruction decoding part of misaligned ld/st
fault handlers, so it can be reused by ld/st access fault handlers.
Also Added lb/lbu/sb decoding. (previously unreachable by misaligned fault)
sbi_trap_emulate_load/store is now the common handler which takes a `emu`
parameter that is responsible for emulating the misaligned or access fault.
The `emu` callback is expected to fixup the fault, and based on the return
code of `emu`, sbi_trap_emulate_load/store will:
r/wlen => the fixup is successful and regs/mepc needs to be updated.
0 => the fixup is successful, but regs/mepc should be left untouched
(this is usually used if `emu` does `sbi_trap_redirect`)
-err => failed, sbi_trap_error will be called
For now, load/store access faults are blindly redirected. It will be
enhanced in the following patches.
Signed-off-by: Bo Gan <ganboing@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>