On 6/30/25 1:00 PM, Philippe Mathieu-Daudé wrote:
Hi Daniel,
On 30/6/25 15:22, Daniel Henrique Barboza wrote:
The RISC-V target has *a lot* of CPU registers, with more registers
being added along the way when new extensions are added. In this world,
'info registers' will throw a wall of text that can be annoying to deal
with when the user wants to verify the value of just a couple of
registers.
Add a new 'info register' HMP command that prints a specific register.
The semantics, and implementation, is similar to what 'info registers'
already does, i.e. '-a' will print a register for all VCPUs and it's
possible to print a reg for a specific VCPU.
A RISC-V implementation is included via riscv_cpu_dump_register().
Here's an example:
Welcome to Buildroot
buildroot login: QEMU 10.0.50 monitor - type 'help' for more information
(qemu) info register mstatus
CPU#0
mstatus 0000000a000000a0
(qemu) info register mstatus -a
CPU#0
mstatus 0000000a000000a0
CPU#1
mstatus 0000000a000000a0
(qemu)
The API is introduced as TARGET_RISCV only.
Cc: Dr. David Alan Gilbert <d...@treblig.org>
Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com>
Cc: Philippe Mathieu-Daudé <phi...@linaro.org>
Signed-off-by: Daniel Henrique Barboza <dbarb...@ventanamicro.com>
---
hmp-commands-info.hx | 17 +++++++++++++
hw/core/cpu-common.c | 8 ++++++
include/hw/core/cpu.h | 11 +++++++++
include/monitor/hmp-target.h | 1 +
monitor/hmp-cmds-target.c | 30 ++++++++++++++++++++++
target/riscv/cpu.c | 48 ++++++++++++++++++++++++++++++++++++
6 files changed, 115 insertions(+)
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
index 639a450ee5..f3561e4a02 100644
--- a/hmp-commands-info.hx
+++ b/hmp-commands-info.hx
@@ -113,6 +113,23 @@ SRST
Show the cpu registers.
ERST
+#if defined(TARGET_RISCV)
Just make this command available for all targets, displaying
"No such register" or better when no handler registered.
What about "<targe-name> does not support this command" ?
+ {
+ .name = "register",
+ .args_type = "register:s,cpustate_all:-a,vcpu:i?",
+ .params = "[register|-a|vcpu]",
+ .help = "show a cpu register (-a: show the register value for all
cpus;"
+ " vcpu: specific vCPU to query; show the current CPU's
register if"
+ " no vcpu is specified)",
I'd invert the default behavior: dump for all vcpus except if a specific
one is specified.
Fair enough.
I wonder about a 'info register -h' do list all register names available.
That's a neat idea. I'll see what I can do.
Thanks,
Daniel
+ .cmd = hmp_info_register,
+ },
+
+SRST
+ ``info register``
+ Show a cpu register.
+ERST
+#endif
Regards,
Phil.
