diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2020-05-07 14:47:55 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2020-05-14 15:03:08 +0100 |
| commit | c888f7e0fdcc09c86004330ab5cad62bf98cc71c (patch) | |
| tree | 13e517c10433aeed092c6977c7dea558e02d3573 /target | |
| parent | 035b448b84f3557206abc44d786c5d3db2638f7d (diff) | |
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
Diffstat (limited to 'target')
| -rw-r--r-- | target/arm/cpu_tcg.c | 1 | ||||
| -rw-r--r-- | target/arm/gdbstub.c | 22 |
2 files changed, 19 insertions, 4 deletions
diff --git a/target/arm/cpu_tcg.c b/target/arm/cpu_tcg.c index 591baef535..00b0e08f33 100644 --- a/target/arm/cpu_tcg.c +++ b/target/arm/cpu_tcg.c @@ -605,6 +605,7 @@ static void arm_v7m_class_init(ObjectClass *oc, void *data) #endif cc->cpu_exec_interrupt = arm_v7m_cpu_exec_interrupt; + cc->gdb_core_xml_file = "arm-m-profile.xml"; } static const ARMCPUInfo arm_tcg_cpus[] = { diff --git a/target/arm/gdbstub.c b/target/arm/gdbstub.c index 063551df23..ecfa88f8e6 100644 --- a/target/arm/gdbstub.c +++ b/target/arm/gdbstub.c @@ -57,8 +57,12 @@ int arm_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n) } return gdb_get_reg32(mem_buf, 0); case 25: - /* CPSR */ - return gdb_get_reg32(mem_buf, cpsr_read(env)); + /* CPSR, or XPSR for M-profile */ + if (arm_feature(env, ARM_FEATURE_M)) { + return gdb_get_reg32(mem_buf, xpsr_read(env)); + } else { + return gdb_get_reg32(mem_buf, cpsr_read(env)); + } } /* Unknown register. */ return 0; @@ -98,8 +102,18 @@ int arm_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n) } return 4; case 25: - /* CPSR */ - cpsr_write(env, tmp, 0xffffffff, CPSRWriteByGDBStub); + /* CPSR, or XPSR for M-profile */ + if (arm_feature(env, ARM_FEATURE_M)) { + /* + * Don't allow writing to XPSR.Exception as it can cause + * a transition into or out of handler mode (it's not + * writeable via the MSR insn so this is a reasonable + * restriction). Other fields are safe to update. + */ + xpsr_write(env, tmp, ~XPSR_EXCP); + } else { + cpsr_write(env, tmp, 0xffffffff, CPSRWriteByGDBStub); + } return 4; } /* Unknown register. */ |