WIP: Raspberry Pi 4 support
The Raspberry Pi 4 is more radically different from its predecessors than any previous new generation of the Raspberry Pi. As such, it has unfortunately not been possible to get the RISC OS port fully functional before launch.
In particular, note that USB and Ethernet are completely non-functional at present, and so this is not yet considered suitable for general users.
If you are willing and able to assist in the remaining portion of the board bring-up process, you will need to build the ROM from source, pulling this development branch into your source tree. You will also need, at minimum, RiscOS/Sources/Programmer/HdrSrc!1 (merged), RiscOS/Sources/Kernel!1 (merged) and RiscOS/Sources/Video/HWSupport/BCMVideo!1 (merged) if they have not yet been merged to master when you are reading this.
Also, you will need:
- a serial lead and terminal application on another machine to drive the UART on header pins 6, 8 and 10 at 115200 baud, 8N1
- to work around a bug in current versions of the firmware, you need to copy the file
bcm2711-rpi-4-b.dtbfrom a Raspbian install into your boot partition
- to hand-edit your
start.elffile as per e5b17810 log
- in Kernel/hdr/Options, set
- in HAL_BCM2835/hdr/BCM2835, set
- since DHCP hangs indefinitely, remove
- since the desktop can't be driven over serial, and we seem to be getting CMOS resets on every boot at present, q quick way to ensure we don't leave the command line is to knock the Desktop module out from the Components file