Ideas on PS Configuration to be more modular

[magni...@gmail.com]

So i run into a problem now, i want to enable the CAN-Bus controllers:

1. I need to create a derivated System design (used the GPIO example) reconfiguring the ZYNQ_PS to enable the CAN controllers and the MIO Pins.

2. Need to create a new FSBL (started with fresh HW export and new BSP)

3. Create a new BOOT.BIN by adding a Release compiled FSBL.elf + U-BOOT.elf from krtkl github

4. pray and see its not working (blank console) for however reasons (my idea here is the ps7 in the gpio example is not configured right?)

So what if:

we play with u-boot to reconfigure the ps7 registers based on the config folder?

so one idea could be a modified ps7_init packed into an elf (but no idea here howto return to u-boot after program end)

goal would be to allow configurations to modify the ps7 peripherals or mio's without going full stack compile (esp if i decide later on to use I2C or SPI too, guessing the PiSmasher has similar problems).

Alternative for my usecase would be to add the can controllers to the PL but you run into similar problems with the AXI-Interconnects and IRQs (speaking here from issues i had with another project earlier this year).

So imho the problem lies in the "bad" design from xilinx to configure such stuff in the FSBL, a selective reconfiguration might be of help here :)

[magni...@gmail.com]

after some tinkering the fsbl starts now (no idea why, but i started from scratch again clean with the gpio example)

but now i found the ps7 init stuff in the u-boot aswell https://github.com/krtkl/snickerdoodle-u-boot/blob/b9fe8824d8c11f6fafd9d384d3cbd0803786877f/board/xilinx/zynq/snickerdoodle_hw_platform/ps7_init_gpl.c  

now digging deeper i found this http://www.wiki.xilinx.com/U-Boot+Secondary+Program+Loader 
here is described that u-boot can replace (or integrate the fsbl) but needs the ps7 init stuff.

So what happens here is the fsbl is executed and does the ps7 init and then u-boot comes and configures the same stuff a second time.