target/arm: Don't put FPEXC and FPSID in org.gnu.gdb.arm.vfp XML

Currently we send VFP XML which includes D0..D15 or D0..D31, plus
FPSID, FPSCR and FPEXC.  The upstream GDB tolerates this, but its
definition of this XML feature does not include FPSID or FPEXC.  In
particular, for M-profile cores there are no FPSID or FPEXC
registers, so advertising those is wrong.

Move FPSID and FPEXC into their own bit of XML which we only send for
A and R profile cores.  This brings our definition of the XML
org.gnu.gdb.arm.vfp feature into line with GDB's own (at least for
non-Neon cores...) and means we don't claim to have FPSID and FPEXC
on M-profile.

(It seems unlikely to me that any gdbstub users really care about
being able to look at FPEXC and FPSID; but we've supplied them to gdb
for a decade and it's not hard to keep doing so.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210921162901.17508-5-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-09-21 17:29:00 +01:00
parent 89f4f20e27
commit b355f08a37
9 changed files with 61 additions and 26 deletions

View File

@ -1,5 +1,5 @@
TARGET_ARCH=aarch64
TARGET_BASE_ARCH=arm
TARGET_SUPPORTS_MTTCG=y
TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_XML_FILES= gdb-xml/aarch64-core.xml gdb-xml/aarch64-fpu.xml gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_NEED_FDT=y

View File

@ -1,6 +1,6 @@
TARGET_ARCH=arm
TARGET_SYSTBL_ABI=common,oabi
TARGET_SYSTBL=syscall.tbl
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_HAS_BFLT=y
CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

View File

@ -1,4 +1,4 @@
TARGET_ARCH=arm
TARGET_SUPPORTS_MTTCG=y
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_NEED_FDT=y

View File

@ -2,6 +2,6 @@ TARGET_ARCH=arm
TARGET_SYSTBL_ABI=common,oabi
TARGET_SYSTBL=syscall.tbl
TARGET_WORDS_BIGENDIAN=y
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_XML_FILES= gdb-xml/arm-core.xml gdb-xml/arm-vfp.xml gdb-xml/arm-vfp3.xml gdb-xml/arm-vfp-sysregs.xml gdb-xml/arm-neon.xml gdb-xml/arm-m-profile.xml
TARGET_HAS_BFLT=y
CONFIG_ARM_COMPATIBLE_SEMIHOSTING=y

View File

@ -82,7 +82,5 @@
<reg name="q14" bitsize="128" type="neon_q"/>
<reg name="q15" bitsize="128" type="neon_q"/>
<reg name="fpsid" bitsize="32" type="int" group="float"/>
<reg name="fpscr" bitsize="32" type="int" group="float"/>
<reg name="fpexc" bitsize="32" type="int" group="float"/>
</feature>

View File

@ -0,0 +1,17 @@
<?xml version="1.0"?>
<!-- Copyright (C) 2021 Linaro Ltd.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
These are A/R profile VFP system registers. Debugger users probably
don't really care about these, but because we used to (incorrectly)
provide them to gdb in the org.gnu.gdb.arm.vfp XML we continue
to do so via this separate XML.
-->
<!DOCTYPE feature SYSTEM "gdb-target.dtd">
<feature name="org.qemu.gdb.arm.vfp-sysregs">
<reg name="fpsid" bitsize="32" type="int" group="float"/>
<reg name="fpexc" bitsize="32" type="int" group="float"/>
</feature>

View File

@ -23,7 +23,5 @@
<reg name="d14" bitsize="64" type="float"/>
<reg name="d15" bitsize="64" type="float"/>
<reg name="fpsid" bitsize="32" type="int" group="float"/>
<reg name="fpscr" bitsize="32" type="int" group="float"/>
<reg name="fpexc" bitsize="32" type="int" group="float"/>
</feature>

View File

@ -39,7 +39,5 @@
<reg name="d30" bitsize="64" type="float"/>
<reg name="d31" bitsize="64" type="float"/>
<reg name="fpsid" bitsize="32" type="int" group="float"/>
<reg name="fpscr" bitsize="32" type="int" group="float"/>
<reg name="fpexc" bitsize="32" type="int" group="float"/>
</feature>

View File

@ -144,11 +144,7 @@ static int vfp_gdb_get_reg(CPUARMState *env, GByteArray *buf, int reg)
}
switch (reg - nregs) {
case 0:
return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPSID]);
case 1:
return gdb_get_reg32(buf, vfp_get_fpscr(env));
case 2:
return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPEXC]);
}
return 0;
}
@ -172,13 +168,31 @@ static int vfp_gdb_set_reg(CPUARMState *env, uint8_t *buf, int reg)
}
}
switch (reg - nregs) {
case 0:
vfp_set_fpscr(env, ldl_p(buf));
return 4;
}
return 0;
}
static int vfp_gdb_get_sysreg(CPUARMState *env, GByteArray *buf, int reg)
{
switch (reg) {
case 0:
return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPSID]);
case 1:
return gdb_get_reg32(buf, env->vfp.xregs[ARM_VFP_FPEXC]);
}
return 0;
}
static int vfp_gdb_set_sysreg(CPUARMState *env, uint8_t *buf, int reg)
{
switch (reg) {
case 0:
env->vfp.xregs[ARM_VFP_FPSID] = ldl_p(buf);
return 4;
case 1:
vfp_set_fpscr(env, ldl_p(buf));
return 4;
case 2:
env->vfp.xregs[ARM_VFP_FPEXC] = ldl_p(buf) & (1 << 30);
return 4;
}
@ -434,15 +448,25 @@ void arm_cpu_register_gdb_regs_for_features(ARMCPU *cpu)
34, "aarch64-fpu.xml", 0);
}
#endif
} else if (arm_feature(env, ARM_FEATURE_NEON)) {
} else {
if (arm_feature(env, ARM_FEATURE_NEON)) {
gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
51, "arm-neon.xml", 0);
49, "arm-neon.xml", 0);
} else if (cpu_isar_feature(aa32_simd_r32, cpu)) {
gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
35, "arm-vfp3.xml", 0);
33, "arm-vfp3.xml", 0);
} else if (cpu_isar_feature(aa32_vfp_simd, cpu)) {
gdb_register_coprocessor(cs, vfp_gdb_get_reg, vfp_gdb_set_reg,
19, "arm-vfp.xml", 0);
17, "arm-vfp.xml", 0);
}
if (!arm_feature(env, ARM_FEATURE_M)) {
/*
* A and R profile have FP sysregs FPEXC and FPSID that we
* expose to gdb.
*/
gdb_register_coprocessor(cs, vfp_gdb_get_sysreg, vfp_gdb_set_sysreg,
2, "arm-vfp-sysregs.xml", 0);
}
}
gdb_register_coprocessor(cs, arm_gdb_get_sysreg, arm_gdb_set_sysreg,
arm_gen_dynamic_sysreg_xml(cs, cs->gdb_num_regs),