diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2022-06-30 20:41:14 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2022-07-07 11:37:33 +0100 |
| commit | 40b200279c98ea0c223fa5a2bdeb4aee40d4e40e (patch) | |
| tree | 8a017bb1bf96af624d7185d3ba76cb85197baff6 | |
| parent | f43ee493c270a27876a55e9636bc4824881d1bbd (diff) | |
target/arm: Suppress debug exceptions when OS Lock set
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.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220630194116.3438513-4-peter.maydell@linaro.org
| -rw-r--r-- | target/arm/debug_helper.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/target/arm/debug_helper.c b/target/arm/debug_helper.c index 9a78c1db96..691b9b74c4 100644 --- a/target/arm/debug_helper.c +++ b/target/arm/debug_helper.c @@ -142,6 +142,9 @@ static bool aa32_generate_debug_exceptions(CPUARMState *env) */ bool arm_generate_debug_exceptions(CPUARMState *env) { + if (env->cp15.oslsr_el1 & 1) { + return false; + } if (is_a64(env)) { return aa64_generate_debug_exceptions(env); } else { |