Support device packs for peripheral registers

[chrissnow]

To be able to debug at low level we need to support SVD files.

the easiest way at the moment is to add to launch.json(which gets overwritten), for example
"svdPath": "Keil::STM32WBxx_DFP@1.4.0",
"deviceName": "STM32WB55RGVx",

We already have deviceName in targets.json (device_name)
svdPath is a bit harder to do nicely since the packs are versioned and it doesn't seem obvious how to get the "latest" pack
Based on this we could add a new field to targets.json, perhaps "cmsis_pack"?

I assume then we need to set some variables in cmake here?

mbed-os/tools/cmake/UploadMethodManager.cmake

Line 56 in 5354079

Then add it launch.json here

mbed-os/tools/cmake/mbed_ide_debug_cfg_generator.cmake

Line 143 in 5354079

\"overrideRestartCommands\": [\"${UPLOAD_RESTART_COMMANDS_FOR_JSON}\"],

Happy to start a PR if this is the right approach.

[multiplemonomials]

This would be really awesome, I would love to have the SVD available when debugging. For the SVD path, you should actually be able to get that information from targets/cmsis_mcu_descriptions.json by looking up by the device_name and finding the from_pack element. By all means, make a PR!

[chrissnow]

Made a start on this, unfortunately CMAKE's native support for JSON doesn't support JSON5 which means it cant cope with hex numbers in cmsis_mcu_descriptions.json5

[cmake] CMake Error at mbed-os/tools/cmake/mbed_ide_debug_cfg_generator.cmake:127 (string):
[cmake]   string sub-command JSON failed parsing json string: * Line 330, Column 26
[cmake] 
[cmake]     Missing ',' or '}' in object declaration

[multiplemonomials]

ah rip. Yeah sounds like you need a python script

[chrissnow]

Would adding it to tools/python/mbed_tools/build/config.py work?
Could then set the variables in mbed_config.cmake

[chrissnow]

Progress so far is here
https://github.com/smartsentry/mbed-os/tree/SVD

if you add the below to your cmakelists it will work
set(MBED_SVD_NAME "Keil::STM32WBxx_DFP@1.4.0")
I'm a bit lost how to get that defined from cmsis_mcu_descriptions.json5 though...

[chrissnow]

@multiplemonomials any thoughts on parsing the JSON5 and setting MBED_SVD_NAME

[multiplemonomials]

Here's an example from my memory bank code of interacting with that file