We are trying to do some deviated thing - bring up a firmware on M4 pair of OMAP5 (IPU). This firmware should be started with minimal boot time by bootloader and do its job ASAP, but still be able to serve LK running on A15 once that LK is up. Currently we are thinking about architecture for that firmware.
We have checked simple OSless firmware. We successfully booted it, even got some prints to debug UART. But it is not what we want. Running some services and communicate with LK on A15 on OSless firmware looks like reinventing the wheel.
We are evaluating SYS/BIOS for the task. It looks interesting for our tast, but there are some unclear points. Could we get some clarifications on following:
- As we understand, pure Sys/Bios is not really made for OMAP's IPU. All SDKs and drivers advertised for Sys/Bios are not suitable for OMAP devices.
- As I understand, there is a one product based on Sys/Bios and made for OMAP's IPU - Ducati. For the Ducati case, Sys/Bios was feat by RPMsg (not considering ISP, camera drivers, OMX). RPMsg's intention is communicating with LK on A15.
- Is there any document what describes how to boot Sys/Bios? Is there a ready example on how to boot Sys/Bios from f.e. u-boot?
- Ducati (even Sys/Bios-RPMsg) build product is elf. Parsing elf in bootloader is not nice idea considering boot time restrictions. Is it possible getting Sys/Bios-RPMsg binary products?
- Is there available Sys/Bios-RPMsg implementations with support of SMP on OMAP's IPU?