target/arm: Use correct GDB XML for M-profile cores

GDB's remote protocol requires M-profile cores to use the feature
name 'org.gnu.gdb.arm.m-profile' instead of the 'org.gnu.gdb.arm.core'
feature used for A- and R-profile cores. We weren't doing this, which
meant GDB treated our M-profile cores like A-profile ones. This mostly
doesn't matter, but for instance means that it doesn't correctly
handle backtraces where an M-profile exception frame is involved.

Ship a copy of GDB's arm-m-profile.xml and use it on the M-profile
cores.  The integer registers have the same offsets as the
arm-core.xml, but register 25 is the M-profile XPSR rather than the
A-profile CPSR, so we need to update arm_cpu_gdb_read_register() and
arm_cpu_gdb_write_register() to handle XSPR reads and writes.

Fixes: https://bugs.launchpad.net/qemu/+bug/1877136
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200507134755.13997-1-peter.maydell@linaro.org

1 files changed, 2 insertions, 2 deletions

diff --git a/configure b/configure
index c50c006b86..26084fc53a 100755
--- a/configure
+++ b/configure
@@ -7806,14 +7806,14 @@ case "$target_name" in
     TARGET_SYSTBL_ABI=common,oabi
     bflt="yes"
     mttcg="yes"
-    gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
+    gdb_xml_files="arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml arm-m-profile.xml"
   ;;
   aarch64|aarch64_be)
     TARGET_ARCH=aarch64
     TARGET_BASE_ARCH=arm
     bflt="yes"
     mttcg="yes"
-    gdb_xml_files="aarch64-core.xml aarch64-fpu.xml arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml"
+    gdb_xml_files="aarch64-core.xml aarch64-fpu.xml arm-core.xml arm-vfp.xml arm-vfp3.xml arm-neon.xml arm-m-profile.xml"
   ;;
   cris)
   ;;