Cool. I couldn't get Android and JFFS2 running. I know it is possible to loop-mount ext3 on JFFS2 to bridge the mmap problem with the data partition. UBIFS is an all-inclusive solution for me at the moment and is quite simple and as oppose to ext3 knows how to handle flash with all its gotchas. As far as I know it is JFFS2, YAFFS2 and UBIFS that is tailored for flash devices.
Well, the options are legio it seems but do yourself a favour and look into UBIFS. I'll be sitting in the corner and eat my humble pie... On Nov 11, 2:56 pm, Sean McNeil <[EMAIL PROTECTED]> wrote: > mvniekerk wrote: > > Well, I can help you with this much - jffs2 + Android = No Go. It will > > Not true. Android runs perfectly on the Openmoko Freerunner using JFFS2 > for root and system. You need to qualify your statement as the only real > partition that needs mmap is the /data partition. What I did for that is > to split the sdcard into 2 partitions: fat for user data like music, > videos, etc, and ext3 for the /data partition. > > > run a few apps until the actual zygote stuff needs to run. mmap is the > > thing that will screw you over - you only get mmap with read only > > jffs2. > > yaffs2 + NOR = No Go. It will fall over and flop. > > UBIFS + NOR + Android = Works well actually. Got it running on our > > iMX31 board with NOR. I'll post some instructions to get UBIFS working > > if you need it. UBIFS = JFFS3. It has compression and a lot of other > > cool stuff. It also scales well. > > > On Nov 10, 4:10 pm, Markus <[EMAIL PROTECTED]> wrote: > > >> Hi, > > >> yes, we might change to a different file system, but actually, Android > >> uses yaffs2 as main file system or at least it seems like this if you > >> hack into its configuration files. To be honest, we do not know, if > >> this problem is caused by the file system or something else as we are > >> able to do file operations in /data/app during the booting process. > >> The kernel panic occurs after Android finished the booting process. So > >> our guess is that Android starts something, that watches the file > >> system (especially /data/app) and that this service is causing our > >> problem. Unfortunately, we could not yet locate, which tool is > >> responsible... any guess, what is started in the end of the booting > >> process, that might cause our problem? > > >> Below, a log of the kernel panic. > > >> Bye > >> Markus > > >> busybox cp ApiDemos.apk test > >> Unable to handle kernel paging request at virtual address 00100104 > >> pgd = c70a4000 > >> [00100104] *pgd=870a2031, *pte=857180dd, *ppte=8571880e > >> Internal error: Oops: 81f [#1] PREEMPT > >> Modules linked in: > >> CPU: 0 Not tainted (2.6.24-140-g68eb4b4 #77) > >> PC is at android_unlock_suspend+0x60/0x170 > >> LR is at android_unlock_suspend+0x34/0x170 > >> pc : [<c01ff8b4>] lr : [<c01ff888>] psr: 60000193 > >> sp : c711bea8 ip : c039bac4 fp : c711bee4 > >> r10: c711a000 r9 : 000001e0 r8 : 60000113 > >> r7 : c7de20a0 r6 : c039babc r5 : c039babc r4 : c7de20e0 > >> r3 : c7c35da8 r2 : 00100100 r1 : 00200200 r0 : c7de20e0 > >> Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user > >> Control: 00e5387f Table: 870a4000 DAC: 00000015 > >> Process FileObserver (pid: 1675, stack limit = 0xc711a260) > >> Stack: (0xc711bea8 to 0xc711c000) > >> bea0: c710401c c7cfac40 c711bed4 c711bec0 c00603cc > >> c006035c > >> bec0: c73dc3c0 00000000 c73dc3d0 c7de20a0 c73dc3c0 c711a000 c711befc > >> c711bee8 > >> bee0: c00c4f90 c01ff860 c73dc3c0 46a2cba4 c711bf4c c711bf00 c00c57d0 > >> c00c4f30 > >> bf00: c003f92c 46a2cb84 c7cfac70 00000000 c7cfac40 c005b298 c711bf18 > >> c711bf18 > >> bf20: c02bfa58 c7043ea0 46a2cb84 c711bf78 00000200 c0025004 c711a000 > >> 41046fc0 > >> bf40: c711bf74 c711bf50 c00961a4 c00c5634 c711bf74 c711bf60 c7043ea0 > >> fffffff7 > >> bf60: 00000000 00000000 c711bfa4 c711bf78 c00965ec c00960fc 00000000 > >> 00000000 > >> bf80: 001ce0b0 00000001 00000f4c ad352cd8 001cf5b8 00000003 00000000 > >> c711bfa8 > >> bfa0: c0024e80 c00965b4 00000f4c ad352cd8 0000001e 46a2cb84 00000200 > >> fd1fafed > >> bfc0: 00000f4c ad352cd8 001cf5b8 00000003 46a2cda0 41046fd4 41046fc0 > >> 00000001 > >> bfe0: ad353458 46a2cb48 ad3414c9 afe0b50c 00000010 0000001e 00ff00ff > >> 00ff00ff > >> Backtrace: > >> [<c01ff854>] (android_unlock_suspend+0x0/0x170) from [<c00c4f90>] > >> (remove_kevent+0x6c/0x94) > >> [<c00c4f24>] (remove_kevent+0x0/0x94) from [<c00c57d0>] (inotify_read > >> +0x1a8/0x1e4) > >> r4:46a2cba4 > >> [<c00c5628>] (inotify_read+0x0/0x1e4) from [<c00961a4>] (vfs_read > >> +0xb4/0x144) > >> [<c00960f0>] (vfs_read+0x0/0x144) from [<c00965ec>] (sys_read > >> +0x44/0x70) > >> r7:00000000 r6:00000000 r5:fffffff7 r4:c7043ea0 > >> [<c00965a8>] (sys_read+0x0/0x70) from [<c0024e80>] (ret_fast_syscall > >> +0x0/0x2c) > >> r7:00000003 r6:001cf5b8 r5:ad352cd8 r4:00000f4c > >> Code: e5965000 e5812000 e5843000 e59c3000 (e5821004) > >> Kernel panic - not syncing: Fatal exception > > >> On 9 Nov., 10:16, mvniekerk <[EMAIL PROTECTED]> wrote: > > >>> Your answer lies in UBIFS. There is a port for kernel 2.6.24 up to > >>> 2.6.27. UBIFS is JFFS3 if you like - and it does support mmap. If your > >>> flash chip is of the NOR-type then YAFFS2 will not work - that is what > >>> makes UBIFS so sweet! > >>> To set up a UBI volume for UBIFS is bit of a schlep, but once done it > >>> is a cool piece of equipment. > > >>> On Nov 6, 11:39 pm, Markus <[EMAIL PROTECTED]> wrote: > > >>>> Hi, > > >>>> it is the init process, that cannot start. The kernel is always > >>>> booting fine and only the Android init process is not able to do its > >>>> job. For yaffs2, the booting process stops like > >>>> inhttp://groups.google.com/group/android-porting/browse_thread/thread/d... > >>>> - I'm sorry, that I can't post my own message at the moment, but I do > >>>> not have access to the hardware right now to flash everything... > > >>>> Like in the link above, we get the same problem about the magic > >>>> number, while Android tries to load the core.jar file. After 4 tries, > >>>> Android resigns and reboots. > > >>>> bye > >>>> Markus > > >>>> On 6 Nov., 17:22, "Gergely Kis" <[EMAIL PROTECTED]> wrote: > > >>>>> Hi, > > >>>>> Could you give more information regarding "Android was not able to > >>>>> boot onyaffs2". What were the actual error messages? Did the kernel > >>>>> hang, or the init process? > > >>>>> Best Regards, > >>>>> Gergely > > >>>>> On Thu, Nov 6, 2008 at 4:18 PM, Markus <[EMAIL PROTECTED]> wrote: > > >>>>>> Hi, > > >>>>>> as I wrote in Android Internals, we ported Android to an i.MX31. > >>>>>> Unfortunately, we have some issues with the file system. > >>>>>> If I use NFS as file system with a modified init.rc config, everything > >>>>>> seems to work well, but this is no option for us as permanent file > >>>>>> system, so we decided to useyaffs2as file system. As this did not > >>>>>> work (Android was not able to boot), we changed to jffs2. jffs2 boots > >>>>>> fine as long as we use a read-only file system. After booting, we can > >>>>>> start many applications, but it seems that those requiring file write > >>>>>> operations fail to start, e.g. the webbrowser. If we change init.rc > >>>>>> config to give file-write permissions, Android is not able to boot > >>>>>> anymore. > > >>>>>> So we have decided to use a mixture ofyaffs2and jffs2, after we saw > >>>>>> this idea at the armv4 port. The basic idea is, that all mmap > >>>>>> operations are done onyaffs2, as jffs2 does not support them. At the > >>>>>> moment, we split the file system to two parts: /data is located on our > >>>>>> yaffs2partition, everything else on our jffs2 partition. The system > >>>>>> boots fine and we can run every application. But now, it is getting > >>>>>> confusing: As soon as Android has finished booting, it is impossible > >>>>>> to write/delete files in /data/app - if we do, we get a kernel panic, > >>>>>> which reports FileObserver to fail. This does not happen, if we do > >>>>>> file accesses before Android has finished its booting process. > > >>>>>> Remembering that we had some cases, in which it was necessary to start > >>>>>> the system with strace running in the background (and discarding the > >>>>>> log), I booted theyaffs2/jffs2 system with strace in the background. > >>>>>> Now, I am able to access files in /data/app, I just get "syscall: > >>>>>> unknown syscall trap 0xe1a00000" reported to my debug console. In this > >>>>>> mode, it is also possible to run applications directly from Eclipse on > >>>>>> the target device. > > >>>>>> So can anybody tell me what is going wrong, if I use ayaffs2only > >>>>>> file system? And why does strace heal those problems with ayaffs2/ > >>>>>> jffs2 system? It just makes the system slower... > > >>>>>> bye > >>>>>> Markus --~--~---------~--~----~------------~-------~--~----~ unsubscribe: [EMAIL PROTECTED] website: http://groups.google.com/group/android-porting -~----------~----~----~----~------~----~------~--~---
