Re: [PATCH] target/arm: Fix debugging of ARMv8M Secure code

[Bartell, Paul]

> On Apr 11, 2023, at 8:24 AM, Peter Maydell <peter.maydell@linaro.org> wrote:
> 
> On Mon, 10 Apr 2023 at 15:38, Bartell, Paul <pbartell@amazon.com> wrote:
>> 
>> You can reproduce the problem by running gdb against an ARMv8M target 
>> running secure mode code (the default).
>> 
>> Running qemu with the following arguments : qemu-system-arm -machine 
>> mps2-an505 -m 16M -cpu cortex-m33 -nographic -semihosting -monitor null 
>> --semihosting-config enable=on,target=native -d guest_errors -kernel 
>> /path/to/binary.elf
>> 
>> With the following .gdbinit file:
>> target extended-remote :1234
>> compare-sections
>> 
>> Upon startup, every symbol in the elf file reports the following error:
>> 
>> Section .text, range 0x10000000 -- 0x10009298: MIS-MATCHED!
>> Section .text.main, range 0x10009298 -- 0x10009300: MIS-MATCHED!
>> Section .text.prvQueueSendTask, range 0x10009300 -- 0x10009338: MIS-MATCHED!
>> 
>> Attempting to debug results in errors constantly (unable to read or write 
>> memory at all).
>> 
>> init_data_sections () at /project/Demo/ARM_MPS/startup.c:95
>> 95      {
>> (gdb) info locals
>> pCopyTable = <error reading variable pCopyTable (Cannot access memory at 
>> address 0x381fffec)>
>> dataIndex = <error reading variable dataIndex (Cannot access memory at 
>> address 0x381fffe8)>
>> 
>> Does that clarify my report sufficiently?
> 
> Could you (a) file a bug and (b) attach a sample test executable
> that demonstrates the problem, please?
> 
> thanks
> -- PMM

Bug filed at https://gitlab.com/qemu-project/qemu/-/issues/1590 with binary 
attached and some additional logs.

Adding the qemu-stable list since semihosting and gdb debugging for all ARMv8M 
targets is broken in the current stable release (v7.2.1) and previous stable 
(v7.2.0). v7.1.0 is not affected.