Re: [9front] Free Carrots #5: MNT Reform

[cinap_lenrek@felloff.net]

the reform.img file is not a iso. it is a sdcard image containing the
flash.bin firmware stuff for the reform and a writable hjfs
root filesystem with 9front.

this gets you to bootargs prompt, where you then can choose between
a network fileserver, nvme, usb or the sdcard as your root filesystem.

> booting the kernel from anything besides sdcard requires more work nobody had done yet.

exactly.

the reform boot currently works like this:

1) boot ROM checks the bootcfg switch to boot either from sdcard or emmc
2) load the flash.bin from offset 33*1k from sdcard or emmc
3) flash.bin contains trusted firmware, ddr init code and uboot
4) uboot runs and searches for a boot.scr file on sdcard or emmc
5) boot.scr loads plan9.ini from sdcard dos partition (NOT 9fat!)
6) boot.scr loads 9reform.u from sdcard dos partition (NOT 9fat!)
7) boot.scr starts the kernel
8) 9front kernel takes over, initializes display, nvme, usb, ethernet ...

until step 8, theres no way to access the nvme drive and everything
runs blind unless you have a serial cable hooked up to the board.

the reform will always boot from sdcard unless someone writes
the drivers for uboot to access pcie and nvme and usb. but even
then, uboot itself will always come from sdcard (or internal emmc)
as we cannot change the cpu's boot rom.
fixing uboot is alot of work and also makes for a complicated
setup to test this during development, potentially needing a
sdcard mux/emulator to be effective (costs over 100 euro).

anyway...

once kernel is running, you can boot a different kernel file
using reboot!/path/to/9reform!method (which uses /dev/reboot
to start another kernel, skipping firmware).

to update the kernel, you can replace 9reform.u file in the sdcard
dos partition (NOT 9fat!).

you can also modify plan9.ini in the sdcard (NOT 9fat!) to set
bootargs= and user= to have different defaults.

--
cinap

PS:

also made a new image yesterday that has sigrids flickerfix
and makes inst/bootsetup stage not complain about not having
/386/mbr.

http://felloff.net/usr/cinap_lenrek/9front-23620b2e70e9de0ce31c6f4f21926a044c5deabc.reform.img.gz.torrent

the latest torrent (i make a new one kind of every weekend)
is always this link:

http://felloff.net/usr/cinap_lenrek/9front-reform.torrent