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@en-sc en-sc commented Jun 20, 2025

  • int riscv_reg_get() and int riscv_reg_set() are implemented in
    terms of reg->type->get/set instead of the other way around. This
    makes it easier to support custom behavior for some registers.
  • Cacheability is determined by reg->type instead of
    riscv_reg_impl_gdb_regno_cacheable().
  • Issues with redirection of priv -> dcsr and pc -> dpc are
    addressed at the "topmost" level.
    • priv and pc are always invalid.
    • Fixed some issues, e.g. the first pc write printed-out an
      uninitialized value:
> reg pc 0
pc (/64): 0x000075da6b33db20

MarekVCodasip and others added 2 commits February 27, 2025 10:27
…pability

Cherrry-picked form https://review.openocd.org/c/openocd/+/8070/21

1) OpenOCD has the capability to 'force' a register read from the
target. This functionality however silently breaks the register
cache: During 'get_reg force' or 'reg <name> force',
reg->type->get() is called which will silently overwrite
dirty items in the register cache, causing a loss of unwritten
register values. This patch fixes that by adding a flush
callback for registers, and by using it when it is needed.

2) The register write commands did not have the 'force' flag;
this was present for register read commands only.
This patch adds it.

3) This patch also introduces the flush_reg_cache command. It
flushes all registers and can optionally invalidate the register
cache after the flush.

For targets which implement the register cache, the flush()
callback in struct reg_arch_type should be implemented (in
separate patches, by the maintainers of each of the target type).

This functionality is also useful for test purposes. Example:
 - In RISC-V, some registers are WARL (write any read legal)
   and this command allows to check this behavior.

We plan to implement the corresponding callback
in the RISC-V target.

Change-Id: I9537a5f05b46330f70aad17f77b2b80dedad068a
Signed-off-by: Marek Vrbka <marek.vrbka@codasip.com>
Signed-off-by: Jan Matyas <jan.matyas@codasip.com>
* `int riscv_reg_get()` and `int riscv_reg_set()` are implemented in
  terms of `reg->type->get/set` instead of the other way around. This
  makes it easier to support custom behavior for some registers.
* Cacheability is determined by `reg->type` instead of
  `riscv_reg_impl_gdb_regno_cacheable()`.
* Issues with redirection of `priv` -> `dcsr` and `pc` -> `dpc` are
  addressed at the "topmost" level.
    - `priv` and `pc` are always invalid.
    - Fixed some issues, e.g. the first `pc` write printed-out an
      uninitialized value:
```
> reg pc 0
pc (/64): 0x000075da6b33db20
```

Change-Id: I514547f455d62b289fb5dee62753bf5d9aa3b8ae
Signed-off-by: Evgeniy Naydanov <evgeniy.naydanov@syntacore.com>
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