I have written assembly code for the RISCV FE310 processor, and have all the manuals for the U54 and U74 CPUs. I also have the schematic and layout diagrams for the BeagleV. What I am missing is the manual for the specific VIC7100 chip that is central to the BeagleV. From the schematic it is clear that there is a lot inside the VIC chip beyond two U74 cores and in order to program it at a low level I need to know things like where the device control registers are mapped, which SPI channels go where, etc.
Where can I find this?
Use DeviceTree which you can traverse for a list of devices, with hardware addresses. It’ll be built and delivered from Open Bios and some services for low level things (send character to debug console) can be provided by System Management mode, which lives beyond your user and machine modes.
It’s a different world than fe310 -class devices.
The JH7100 datasheet is in this repo:
Documentation is still a work in progress and more sections will be added overtime.
FYI - VIC7100 was an internal project name but JH7100 is the official name of the SoC. StarFive has been trying to realign the naming but there are still many references to VIC7100
My project is at a very low level, not with Linux, so I really need to know addresses and bit layouts, not device trees. The information at starfive-tech/beaglev_doc is exactly what I was looking for. I realize that the final board that ships later will not be exactly like this spec, but it is enough to get started. Thank you. I will keep my eye on that repo.