New kernel

[akhaliq]

i'd be waiting for some good exploding news from Aleksei, if its possible.

Aleksei, keep sharing whatever you discover abt new kernel.

[Aleksei]

I wanna switch to writable root file system (JFFS2). Now i can compile the kernel from source with loop device and jffs2 support. Also i can flash zImage and successfuly boot my phone. I can replace cramfs rootfs with jffs2 rootfs, mount and umount it. BUT then i change boot kernel option rootfstype=cramfs with rootfstype=jffs2 and flashed the phone it froze with hellomoto pic. I need a way to see kernel boot output. Any ideas?

[CheshireCat]

When you say you can mount it, are you using the mtdblock device in the flashkit miniroot to do so? I'm not sure if it should make a difference, but the root device is one of Moto's funny roflash devices iirc, and it may be that JFFS2 doesn't like it (perhaps simply because it is ro).

I haven't played with this kernel yet, but the version stuff in the Makefile suggests it might be a bit closer to what Moto actually used to build the kernel for our phones. Shouldn't it be possible to "fix" roflash so that it's not ro?

What about keeping the cramfs or using squashfs, but mounting a vfm or jffs2 device (perhaps the one where ezxlocal lives now) as root, and populating it with symlinks to the cramfs where the "real" files for root are stored. OpenWRT uses this approach, and it seems to work well. The root is easily modified, but there's a ro version of the "core" files handy, and there are startup scripts to allow recovery from these if the rw root is smashed.

[abcslayer]

To view debug out put you may try to attach a JTAG cable to it (notes: there are two interface one for PXA27x and one for Neptune GSM chipset).

[CheshireCat]

Aleksei:

By the way, how did you get around your problem flashing the kernel? I'm trying to add squashfs support to my phone, and having the same trouble with flashcp. Trying to use dd and mtdblock4 caused dd to hang, apparently in a syscall because I couldn't kill it.

[Aleksei]

CheshireCat: I modified a rwflash.c from cyph's flashkit. Replace your rwflash.o with attached to post and flash using flashcp zImage /dev/mtd1.

[CheshireCat]

I checked the device referenced in the kernel command line, it's the same as /dev/roflash on the A780. mtd_debug reports some info on Moto's special roflash devices.

I'd likely need to get these supported as standard MTD devices to get squashfs to boot. You probably need the chip unlocked at boot to mount JFFS2 from it. I think this is well beyond my kernel hacking skill.

I think a good bet might still be to keep the CramFS, and add a linuxrc script that mounts a JFFS2 writable partition (maybe on tffsb, I never use mass-storage mode) filled with symlinks, and pivots the root to that. This could still have a /diska directory, which could be owned by ezx, so that programs that look in /diska (and the samba share in network mode) could effectively share storage with the writable root.

[maxx_730]

So exactly what changed in this release? Nobody analyzed some diff's yet?

[Aleksei]

I found a way to see kernel bootup messages. Now they appear on lcd screen of my e680i )))

[Aleksei]

Now can write to my rootfs without reflashing ))))