Re: [PATCH v2 1/4] gdb/aarch64: record/replay support for LRCPC3

[Ezra Sitorus <ezra.sitorus@arm.com>]

On Fri, May 15, 2026 at 12:50:30AM -0300, Thiago Jung Bauermann wrote:

> In the system headers, this constant is called HWCAP2_LRCPC3.

Yes that's right. I'll change that.
 
> The test program in v1 tried to execute an instruction to detect whether
> LRCPC3 is supported, and in v2 it checks a bit in HWCAP. Nothing wrong
> with that, but the gdb_expect above needs to be adapted accordingly. On
> a machine which doesn't support the feature I see a WARNING, but the
> test program just behaved as expected:
> 
> (gdb) file /home/bauermann/.cache/builds/gdb-native/gdb/testsuite/temp/1223/allow_aarch64_lrcpc3_tests.x
> Reading symbols from /home/bauermann/.cache/builds/gdb-native/gdb/testsuite/temp/1223/allow_aarch64_lrcpc3_tests.x...
> (gdb) run 
> Starting program: /home/bauermann/.cache/builds/gdb-native/gdb/testsuite/temp/1223/allow_aarch64_lrcpc3_tests.x 
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/usr/lib/aarch64-linux-gnu/libthread_db.so.1".
> [Inferior 1 (process 1299) exited with code 01]
> (gdb) WARNING: 
> allow_aarch64_lrcpc3_tests: default case taken
> gdb_caching_proc allow_aarch64_lrcpc3_tests caused gdb_exit to be called
>   gdb_caching_proc allow_aarch64_lrcpc3_tests marked as called
>   gdb_caching_proc get_compiler_info_1 marked as called
>   gdb_caching_proc is_aarch32_target marked as called
>   gdb_caching_proc universal_compile_options_c marked as called
> UNSUPPORTED: gdb.reverse/aarch64-lrcpc3.exp: require failed: allow_aarch64_lrcpc3_tests
> testcase /home/bauermann/src/binutils-gdb/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.exp completed in 26 seconds
 
Ahh I see. I'll compare it with the GCS support testing.

> By the way, is there something specific I need to do to get an FVP
> supporting LRCPC3? I set up FVP with:
> 
> $ shrinkwrap build --overlay=arch/v9.6.yaml ns-edk2.yaml
> 
You need to enable the feature in an overlay file. So I have something like this:

run:
  rtvars:
    ROOTFS:
      value: /path/to/rootfs
    CMDLINE:
      value: loglevel=3 ip=dhcp kpti=off root=/dev/vda2 console=ttyAMA0
    KERNEL:
      value: path/to/Image
  params:
    -C bp.hostbridge.userNetworking: 1
    -C bp.hostbridge.userNetPorts: 8022=22,8123=8123
    -C bp.smsc_91c111.enabled: 1
    -C bp.virtio_net.enabled: 0
    -C cluster0.NUM_CORES: 1
    -C cluster0.has_lrcpc3: 1
    -C cluster0.has_rprfm: 1
    -C pctl.CPU-affinities: 0.0.0.0

which enables LRCPC3, RPRFM and some networking. Then I run like so:
$ shrinkwrap run ns-edk2.yaml --overlay file.yaml.

Also, you can do:
$ shrinkwrap build --overlay=arch/v8.9.yaml ns-edk2.yaml 

which should enable fewer features so it'll run slightly quicker.

On another note, it seems like patch 2 and 3 are OK? Can these be pushed while
I resend this one and wait for Guinevere for patch 4? 

Ezra