Attached tarball of my platform/sx530hs fw:100c :
Thanks for posting this.
Generally, a patch is preferred. If you use windows, tortoise create patch can be used from your working copy. From the command line, you can use svn diff.
It's also helpful if you submit changes for one thing at a time. Implementing filewrite for example is totally independent of the other changes you made. If you post small, self contained contained changes, it's a lot easier to review them.
I enabled filewrite, exp_drv_task and movie_rec tasks.
I disabled jogdial and liveview.
Why did you disable them? This camera does not appear to have a jogdial, but it does have a control wheel which I'd assume is hooked up to the jogdial code.
The taskHook function is an old style not used on this kind of camera. The task hook for this camera happens in taskhook.S
According to the comments, the liveimage task was used for video quality. movie_rec was also implemented in the existing code.
I also removed 'fix_writable_media_flag', as well as 'init_required_fw_features'. It was not clear from reading the port thread that those mods were actually required for the cam to run.. In basic tests, I saw no problems with power-On in play mode, using either button; and I had no problems with my (correctly prepared) bootable SD card.
The 'fix_writable_media_flag' flag fix was in part developed this specific port. For background, see this thread
https://chdk.setepontos.com/index.php?topic=12795.0. Note that the symptom only affected certain SD cards, so the fact yours worked without it is not definitive.
init_required_fw_features is almost certainly also required for some specific overrides.
Generally speaking, I would not remove something unless I understand it enough to have high confidence it's not needed. Unfortunately, we do not have a comprehensive test suite and some workarounds are only needed in very specific cases. If in doubt, asking in the porting thread may save a lot of time and headache.
I wasn't sure how to test exp_drv_task, so beware, it may have bugs.
exp_drv_task is used to implement extra long exposures, generally over 64 seconds. So to verify it, you need to verify that exposure overrides still work, and that you can override > 64 seconds.
Note that if canon darkframe isn't disabled, the camera will be "busy" for the same length of time as the exposure.
Movie_rec was tested from CHDK scripts using cam/gui/buttons. Two small mp4's were made on the cam's SD card; ffplay identifies and plays them.
The movie_rec task is used to implement quality overrides on some cameras, but as mentioned above it appears to require stuff liveimage as well for this port (the old method stopped working for models released in the last few years)
To verify it, you need to verify that videos recorded with different quality settings have different compression levels. Very high compression should be pretty obvious. The defines in platform_camera.h also need to be set up to make the override accessible.
