While there was a brief hiatus in the development of the open firmware for Raspberry Pi, we can now boot Linux straight from bootcode.bin (note, this does require an initrd built in with zImage as there are still issues with eMMC working reliably at boot).
We are also currently investigating and getting closer to getting the following working:
- SB PHY: Preliminary driver for USB PHY initialisation is ready but USB itself relies on the DMA engine working and we’re still figuring that out.
- Centralised power and clock management drivers in the firmware (already used for BCM2708PowerDomainARM and
- eMMC (SDHOST) driver reliability (at the moment it seems to have 1 in 100 or so failure rate, requiring a reboot).
- eMMC (SDHOST) teardown for the Linux kernel.
The current trunk of the rpi-open-firmware is able to boot a minimal Linux kernel image, you will need cmdline.txt, rpi.dtb (compiled device tree for your rPi model) and zImage on your boot partition (same place bootcode.bin resides). You’re encouraged to build a minimal kernel and try it out (a good starting point is this .config file that you could use for your kernel build using the latest Linux kernel, which also includes correctly configured early printk stuff).
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