On 7/1/22 01:11, Peter Maydell wrote:
The "OS Lock" in the Arm debug architecture is a way for software to suppress debug exceptions while it is trying to power down a CPU and save the state of the breakpoint and watchpoint registers. In QEMU we implemented the support for writing the OS Lock bit via OSLAR_EL1 and reading it via OSLSR_EL1, but didn't implement the actual behaviour.The required behaviour with the OS Lock set is: * debug exceptions (apart from BKPT insns) are suppressed * some MDSCR_EL1 bits allow write access to the corresponding EDSCR external debug status register that they shadow (we can ignore this because we don't implement external debug) * similarly with the OSECCR_EL1 which shadows the EDECCR (but we don't implement OSECCR_EL1 anyway) Implement the missing behaviour of suppressing debug exceptions. Signed-off-by: Peter Maydell<peter.mayd...@linaro.org> --- target/arm/debug_helper.c | 3 +++ 1 file changed, 3 insertions(+)
Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
