provide an enum for registers

[Sauci]

Hi,

I would like to know if it would be possible to provide an enumeration to clarify the calls to register_read(self, register_index). I guess that calling this function with register_index = 0 the value of register r0 will be returned, but I'm not sure what index should be used for CPS register, more generally what index should be used for banked registers. I guess that an enum like shown bellow might help the users:

REG_R0 = 0
...
REG_R7 = 7
REG_R8_USR = ?
REG_R8_FIQ = ?
REG_R9_USR = ?
REG_R9_FIQ = ?

I know it is possible to read the banked register r8_fiq with GDB, even if the controller is not in FIQ mode, but I don't know if it would be possible using the DLL.

here's a link showing different registers available for a cortex-r5 controller (only as example).

Thanks for your feedback

[hkpeprah]

Sounds like a good idea / enhancement. Something like a registers enum with

class Registers(enum):
    ARM_CORTEX_R5_R0 = 0
    <...>
    ARM_CORTEX_R5_CPS

[sstallion]

Does the JLink API provide anything similar?

…

On Tue, Dec 11, 2018, 1:00 PM Ford ***@***.*** wrote: Sounds like a good idea / enhancement. Something like a registers enum with class Registers(enum): ARM_CORTEX_R5_R0 = 0 <...> ARM_CORTEX_R5_CPS — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#46 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFtLiBN9I0OihDRgaDDBig47c8gKVYiGks5u4ADigaJpZM4ZNRv8> .

[hkpeprah]

There's the register_name() method which takes an index and returns the name of the register at that index. There's also register_list() which will return a list of the register numbers. Together you could probably do something like:

register_map = {}
for reg_index in jlink.register_list():
    register_map[jlink.register_name(reg_index)] = reg_index
print(jlink.register_read(register_map['<REGISTER_NAME>']))

[Sauci]

Oh sorry I didn’t see those two functions...
I guess my proposal doesn’t make sense anymore, as the registers are known at runtime. I was thinking that it would be great for auto completion, but it doesn’t seems to be possible.
Should I close the issue?

Sorry again, RTFD the next time

[hkpeprah]

Ah, super sorry about getting back to you late on this. I think probably using the list is the best bet. It might be worth modifying the register commands to support both named and indexed registers if that's something you want to take a look at.

[Sauci]

No problem. Ok, I will add this feature. What do you think about this proposition:

• modifying register_read(self, register_index) signature to
  register_read(self, register_index=None, register_name=None)
  This change would be backward compatible.

• modifying register_write(self, reg_index, value) signature to
  register_write(self, value, reg_index=None, register_name=None)
  This change wouldn't be backward compatible.

This has the downside to break backward compatibility with current/previous versions of the module, but it keeps a clear interface. Otherwise, if you prefer to keep backward compatibility, I could add functions like read_register_by_name and write_register_by_name.

[hkpeprah]

Hm, personally, I would just override register_index and update the docstring to indicate that we take a string value. In a later (major) release, we can rename register_index -> register. Basically, just do something like:

if isinstance(register_index, six.stringtypes):
    register_index = <convert name to index>

[hkpeprah]

Release with patch should be available in v0.3.0: https://github.com/square/pylink/releases/tag/v0.3.0

[Sauci]

Great, thanks! I guess this issue can be closed?

[hkpeprah]

Sounds good.