[U-Boot] Older u-boot mangles UBI from ubinize 1.5.2
Greetings
I am attempting to port LEDE/OpenWRT to a new device; the TRENDnet TEW-827DRU, which is a IPQ806X-based (AP148) system. It has a NAND flash for storage with a UBI (kernel + squashfs + ubifs).
When my system attempts to attach the UBI, I see the following error from linux:
[ 3.781181] ubi0: attaching mtd11 [ 3.835224] UBI: EOF marker found, PEBs from 40 will be erased [ 3.835384] ubi0: scanning is finished [ 3.840040] ubi0 error: ubi_read_volume_table: the layout volume was not found [ 3.844072] ubi0 error: ubi_attach_mtd_dev: failed to attach mtd11, error -22 [ 3.850897] UBI error: cannot attach mtd11
I took this to google and it turns out that Ram Chandra Jangir here had noted the same issue a few months back, and then I got lucky and saw his patches yesterday:
https://patchwork.ozlabs.org/patch/657285/ https://patchwork.ozlabs.org/patch/624733/
I emailed Ram and he sent me his boot log and it looks identical to mine, so I think it's the same issue. (thx again Ram!)
I tried re-flashing my UBI and tftpbooting my kernel before u-boot could ever get a chance to mangle it, and now I get much further, though I'm still not able to mount my rootfs for unknown reasons:
[ 3.772502] ubi0: attaching mtd11 [ 3.826477] UBI: EOF marker found, PEBs from 40 will be erased [ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430 LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs) [ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 3.956556] Please append a correct "root=" boot option; here are the available partitions:
Any advice on this? Any background information that I can read up on? My google searches have not come up with much. Ram knew about this, but I don't know if it's otherwise a known issue.
The process works fine on the OEM system, so I assume this is some ubinize format change which is incompatible with the older u-boot. Or, the newer kernel code doesn't know how to deal with the UBI once the older u-boot has mangled/attached it.
Seems like a backwards incompatibility issue.
Just to be clear, my kernel is inside the UBI, so u-boot must attach the UBI and read the volume to boot.
Rebuilding and replacing my u-boot is probably not possible for now, though I do have the OEM source. My device has a jtag, but I have not tested it and that's out of my league.
Additional info below:
--
My u-boot version: U-Boot 2012.07 [Standard IPQ806X.LN,r40331]
The old OEM ubinize is 1.2 from mtd-utils-1.4.5.
The old OEM kernel is 3.4.103. New kernel is 4.4.15.
LEDE built from commit 21f460a5dbef5e3ec59e2032b5b113fe045b475f
The new LEDE ubinize version is 1.5.2. The ubinize command (via LEDE's ubinize-image.sh script) to build my image was (paths truncated for readability):
ubinize-image.sh --kernel .../TEW827DRU-uImage .../root.squashfs .../lede-ipq806x-TEW827DRU-squashfs-factory.bin.tmp -p 128KiB -m 2048 -E 5
Notably the new LEDE ubinize command uses "-E 5" whereas the old OEM does not, but I don't think that's related.
The ubinize.ini file looked like:
[kernel] mode=ubi vol_id=0 vol_type=dynamic vol_name=kernel image=/.../TEW827DRU-uImage [rootfs] mode=ubi vol_id=1 vol_type=dynamic vol_name=rootfs image=/.../root.squashfs [rootfs_data] mode=ubi vol_id=2 vol_type=dynamic vol_name=rootfs_data vol_size=1MiB vol_flags=autoresize
Hi!
On Thu, Aug 11, 2016 at 4:26 AM, J Mo jmomo@jmomo.net wrote:
I tried re-flashing my UBI and tftpbooting my kernel before u-boot could ever get a chance to mangle it, and now I get much further, though I'm still not able to mount my rootfs for unknown reasons:
[ 3.772502] ubi0: attaching mtd11 [ 3.826477] UBI: EOF marker found, PEBs from 40 will be erased
WTF is this? Reading the corresponding patch makes me very sad.
[ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs) [ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 3.956556] Please append a correct "root=" boot option; here are the available partitions:
Any advice on this? Any background information that I can read up on? My google searches have not come up with much. Ram knew about this, but I don't know if it's otherwise a known issue.
The process works fine on the OEM system, so I assume this is some ubinize format change which is incompatible with the older u-boot. Or, the newer kernel code doesn't know how to deal with the UBI once the older u-boot has mangled/attached it.
Seems like a backwards incompatibility issue.
Since OpenWRT/LEDE folks did more or less a hard fork of UBI I'm ignoring this issue. If you encounter something like that using vanilla UBI I'm all ears.
That said, I kind of understand that you, OpenWRT/LEDE, have a pile of patches for auto probing rootfs and other runtime stuff but touching the UBI on-flash format is beyond funny. Doing so opens a can of worms and is painful for all parties. There are customers which build their products using OpenWrt and when they change the kernel at some point it will get nasty.
This situation needs to be improved now. I invite you to discuss this changes here on linux-mtd. Especially the stuff where you change the on-flash format. If UBI, or MTD in general, can do a better job in some areas, please tell such that a decent solution can be found. But your ad-hoc hacks need to stop.
Hi Richard,
On Thu, Aug 11, 2016 at 11:51:10AM +0200, Richard Weinberger wrote:
Hi!
On Thu, Aug 11, 2016 at 4:26 AM, J Mo jmomo@jmomo.net wrote:
I tried re-flashing my UBI and tftpbooting my kernel before u-boot could ever get a chance to mangle it, and now I get much further, though I'm still not able to mount my rootfs for unknown reasons:
[ 3.772502] ubi0: attaching mtd11 [ 3.826477] UBI: EOF marker found, PEBs from 40 will be erasedWTF is this? Reading the corresponding patch makes me very sad.
Understandable. However, we also need to experiment and figure out the mess left behind by $vendor which often doesn't leave a lot of reasonable options for 3rd-party firmware to be installed. With regard to that specific hack, I never truly understood why it was needed in first place -- I'm not using it on any UBI-enabled device and believe it's some kind of work-around to allow ubinized images to be written via nandwrite, initially in order to support the vendor/stock sysupgrade-format of a specific device (NETGEAR WNDR4300). Please correct me or add the missing bits needed to understand the use-case. It was added to OpenWrt long ago in r38681...r38683 and by now needed to be fixed several times in r42940, r43287, r44658, r44801 and r44881. Later on it was re-used by a bunch of other devices, e.g. bcm4708-netgear-r6250, bcm4708-netgear-r6300-v2, bcm4708-buffalo-wzr-1750dhp, bcm47081-buffalo-wzr-600dhp2 and probably some more.
Gabor and Rafal should know more about it and why exactly this is needed and supposedly cannot be solved without this hack.
[ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs)
This line hints that the rootfs is non-UBIFS and thus a ubiblock device has been created.
[ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" orunknown-block(31,11): error -2
That lack of a line like [ 3.937296] ubiblock: device ubiblock0_3 (rootfs) set to be root filesystem indicates that ROOT_DEV is already set, e.g. via the kernel's cmdline using the "rootfs=ubi0:rootfs" parameter. As the rootfs isn't UBIFS, this won't work. Check your bootloader's environment or any other sources for kernel cmdline fragments (various OpenWrt/LEDE specific hacks but also the device-tree for things like chosen { bootargs = "..." } which try to hard-code the rootfs to ubi0:rootfs.
[ 3.956556] Please append a correct "root=" boot option; here are theavailable partitions:
Any advice on this? Any background information that I can read up on? My google searches have not come up with much. Ram knew about this, but I don't know if it's otherwise a known issue.
Right. Depending on whether U-Boot's UBI support or the kernel itself first touches the freshly-written UBI device things go wrong, becase only the hacked-up OpenWrt/LEDE kernel does the right magic on firstboot...
Cheers
Daniel
The process works fine on the OEM system, so I assume this is some ubinize format change which is incompatible with the older u-boot. Or, the newer kernel code doesn't know how to deal with the UBI once the older u-boot has mangled/attached it.
Seems like a backwards incompatibility issue.
Since OpenWRT/LEDE folks did more or less a hard fork of UBI I'm ignoring this issue. If you encounter something like that using vanilla UBI I'm all ears.
That said, I kind of understand that you, OpenWRT/LEDE, have a pile of patches for auto probing rootfs and other runtime stuff but touching the UBI on-flash format is beyond funny. Doing so opens a can of worms and is painful for all parties. There are customers which build their products using OpenWrt and when they change the kernel at some point it will get nasty.
This situation needs to be improved now. I invite you to discuss this changes here on linux-mtd. Especially the stuff where you change the on-flash format. If UBI, or MTD in general, can do a better job in some areas, please tell such that a decent solution can be found. But your ad-hoc hacks need to stop.
-- Thanks, //richard
Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
I got that good old feeling... like I just jumped onto a bag of flaming poo. Ha ha
On 08/11/2016 03:40 AM, Daniel Golle wrote:
Understandable. However, we also need to experiment and figure out the mess left behind by $vendor which often doesn't leave a lot of reasonable options for 3rd-party firmware to be installed. With regard to that specific hack, I never truly understood why it was needed in first place -- I'm not using it on any UBI-enabled device and believe it's some kind of work-around to allow ubinized images to be written via nandwrite, initially in order to support the vendor/stock sysupgrade-format of a specific device (NETGEAR WNDR4300). Please correct me or add the missing bits needed to understand the use-case. It was added to OpenWrt long ago in r38681...r38683 and by now needed to be fixed several times in r42940, r43287, r44658, r44801 and r44881. Later on it was re-used by a bunch of other devices, e.g. bcm4708-netgear-r6250, bcm4708-netgear-r6300-v2, bcm4708-buffalo-wzr-1750dhp, bcm47081-buffalo-wzr-600dhp2 and probably some more.
Gabor and Rafal should know more about it and why exactly this is needed and supposedly cannot be solved without this hack.
I'm also confused about WTF that patch does. If it was device-specific to comply with OEM-hackery, why apply it generally?
Hm, I just found another example. I don't know why this didn't turn up in my searches yesterday since it's a perfect match with the EXACT error. This too was on a QSDK AP148:
https://patchwork.ozlabs.org/patch/509468/
I think I'll go rip that patch out here in a bit, recompile my image, and see what happens.
[ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs)
This line hints that the rootfs is non-UBIFS and thus a ubiblock device has been created.
[ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" orunknown-block(31,11): error -2
That lack of a line like [ 3.937296] ubiblock: device ubiblock0_3 (rootfs) set to be root filesystem indicates that ROOT_DEV is already set, e.g. via the kernel's cmdline using the "rootfs=ubi0:rootfs" parameter. As the rootfs isn't UBIFS, this won't work. Check your bootloader's environment or any other sources for kernel cmdline fragments (various OpenWrt/LEDE specific hacks but also the device-tree for things like chosen { bootargs = "..." } which try to hard-code the rootfs to ubi0:rootfs.
Thanks for the insight.
The idea was to have a UBI with three volumes: kernel, rootfs(squashfs), and the rootfs_data overlay(ubifs).
One of my problems is that someone thought it was a great idea to name the SMEM NAND UBI partition "rootfs". There's a patch out there which is supposed to fix that, (rename to "ubi") but it's apparently not working for me. The auto rootfs selection method might be trying to use the smem/mtd parition named "rootfs" instead of the UBI volume named "rootfs"?
And yes, my DTS has: bootargs = "console=ttyMSM0,115200n8 ubi.mtd=11 root=ubi0:rootfs rootfstype=squashfs";
Is that not valid? Looks right to me.
Right. Depending on whether U-Boot's UBI support or the kernel itself first touches the freshly-written UBI device things go wrong, becase only the hacked-up OpenWrt/LEDE kernel does the right magic on firstboot...
The kernel is in the UBI, so u-boot is going to attach it. I can't get around that without doing major reconstructive surgery to how this thing was designed to boot.
The number of OpenWRT/LEDE devices that have KERNEL_IN_UBI set are tiny. I think I only saw one or two others, and they were obscure or dev boards. This is likely why the issue hasn't come up before, and it could have been a problem for awhile and nobody noticed.
I don't know who's to blame. That's why I started this three-way cross posting clusterfark. =)
I'm most tempted to blame the kernel rather than u-boot. After all, I can change the kernel, and the old kernel worked fine.
On 08/11/2016 04:28 AM, J Mo wrote:
Hm, I just found another example. I don't know why this didn't turn up in my searches yesterday since it's a perfect match with the EXACT error. This too was on a QSDK AP148:
https://patchwork.ozlabs.org/patch/509468/
I think I'll go rip that patch out here in a bit, recompile my image, and see what happens.
Yep, I just ripped out that patch, rebuilt, and the UBI is working correctly-ish now:
[ 3.781400] ubi0: attaching mtd11 [ 4.475744] ubi0: scanning is finished [ 4.490924] ubi0 warning: print_rsvd_warning: cannot reserve enough PEBs for bad PEB handling, reserved 5, need 40 [ 4.492040] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 4.500155] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 4.506033] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 4.512808] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 4.519603] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 4.526430] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 4.532680] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 1454555262 [ 4.539660] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 5 [ 4.549141] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 4.558711] block ubiblock0_1: created from ubi0:1(rootfs) [ 4.563771] hctosys: unable to open rtc device (rtc0) [ 4.576690] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 4.576718] Please append a correct "root=" boot option; here are the available partitions: [ 4.583956] 1f00 256 mtdblock0 (driver?) [ 4.596076] 1f01 1280 mtdblock1 (driver?) [ 4.601109] 1f02 1280 mtdblock2 (driver?) [ 4.606144] 1f03 2560 mtdblock3 (driver?) [ 4.611178] 1f04 1152 mtdblock4 (driver?) [ 4.616214] 1f05 1152 mtdblock5 (driver?) [ 4.621249] 1f06 2560 mtdblock6 (driver?) [ 4.626283] 1f07 2560 mtdblock7 (driver?) [ 4.631319] 1f08 5120 mtdblock8 (driver?) [ 4.636352] 1f09 512 mtdblock9 (driver?) [ 4.641387] 1f0a 512 mtdblock10 (driver?) [ 4.646423] 1f0b 65536 mtdblock11 (driver?) [ 4.651544] 1f0c 384 mtdblock12 (driver?) [ 4.656666] 1f0d 5120 mtdblock13 (driver?) [ 4.661786] 1f0e 65536 mtdblock14 (driver?) [ 4.666909] fe00 2728 ubiblock0_1 (driver?) [ 4.672103] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,11)
My squashfs root isn't mounting but that's another patch/issue.
So that 494-mtd-ubi-add-EOF-marker-support.patch has gotta go or get fixed. It's almost certainly been fking stuff up for a long time and just nobody noticed before now because almost nobody has a kernel in their UBI. It wasn't in OpenWRT AA/12.09, so it wasn't in the QSDK which my device is based on.
Hi,
On Thu, Aug 11, 2016 at 05:18:08AM -0700, J Mo wrote:
On 08/11/2016 04:28 AM, J Mo wrote:
Hm, I just found another example. I don't know why this didn't turn up in my searches yesterday since it's a perfect match with the EXACT error. This too was on a QSDK AP148:
https://patchwork.ozlabs.org/patch/509468/
I think I'll go rip that patch out here in a bit, recompile my image, and see what happens.
Yep, I just ripped out that patch, rebuilt, and the UBI is working correctly-ish now:
[ 3.781400] ubi0: attaching mtd11 [ 4.475744] ubi0: scanning is finished [ 4.490924] ubi0 warning: print_rsvd_warning: cannot reserve enough PEBs for bad PEB handling, reserved 5, need 40 [ 4.492040] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 4.500155] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 4.506033] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 4.512808] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 4.519603] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 4.526430] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 4.532680] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 1454555262 [ 4.539660] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 5 [ 4.549141] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 4.558711] block ubiblock0_1: created from ubi0:1(rootfs) [ 4.563771] hctosys: unable to open rtc device (rtc0) [ 4.576690] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 4.576718] Please append a correct "root=" boot option; here are the available partitions: [ 4.583956] 1f00 256 mtdblock0 (driver?) [ 4.596076] 1f01 1280 mtdblock1 (driver?) [ 4.601109] 1f02 1280 mtdblock2 (driver?) [ 4.606144] 1f03 2560 mtdblock3 (driver?) [ 4.611178] 1f04 1152 mtdblock4 (driver?) [ 4.616214] 1f05 1152 mtdblock5 (driver?) [ 4.621249] 1f06 2560 mtdblock6 (driver?) [ 4.626283] 1f07 2560 mtdblock7 (driver?) [ 4.631319] 1f08 5120 mtdblock8 (driver?) [ 4.636352] 1f09 512 mtdblock9 (driver?) [ 4.641387] 1f0a 512 mtdblock10 (driver?) [ 4.646423] 1f0b 65536 mtdblock11 (driver?) [ 4.651544] 1f0c 384 mtdblock12 (driver?) [ 4.656666] 1f0d 5120 mtdblock13 (driver?) [ 4.661786] 1f0e 65536 mtdblock14 (driver?) [ 4.666909] fe00 2728 ubiblock0_1 (driver?) [ 4.672103] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,11)
My squashfs root isn't mounting but that's another patch/issue.
That's what I told you in the previous mail, removing the rootfs= parameter from the dts should do the trick, because you just cannot mount a ubi device (which is a character device in Linux) with a block-based filesystem (like squashfs). This cannot and won't ever work and you could either leave it to OpenWrt/LEDE's auto-probing to figure out what to do based on the rootfs type (non-ubifs vs. ubifs) or append even more board- and filesystem-specific crap to your cmdline such as ubiblock=... root=/dev/ubiblock0_1 (however, that then won't work for ubifs, thus the auto-probing patches).
So that 494-mtd-ubi-add-EOF-marker-support.patch has gotta go or get fixed.
I agree, however, once again, it depends on how you write the ubinized image to the flash in first place.
It's almost certainly been fking stuff up for a long time and just nobody noticed before now because almost nobody has a kernel in their UBI. It
Not true. As I said, I'm using KERNEL_IN_UBI on all oxnas based targets and also got U-Boot 2014.10 with UBI support touching the flash before the kernel would fixup anything. Have a look at target/linux/oxnas/image/Makefile for a 100% working example.
wasn't in OpenWRT AA/12.09, so it wasn't in the QSDK which my device is based on.
Please read my previous email (I hope you actually received it?) for more details.
Cheers
Daniel
Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
On 08/11/2016 05:31 AM, Daniel Golle wrote:
That's what I told you in the previous mail, removing the rootfs= parameter from the dts should do the trick, because you just cannot mount a ubi device (which is a character device in Linux) with a block-based filesystem (like squashfs). This cannot and won't ever work and you could either leave it to OpenWrt/LEDE's auto-probing to figure out what to do based on the rootfs type (non-ubifs vs. ubifs) or append even more board- and filesystem-specific crap to your cmdline such as ubiblock=... root=/dev/ubiblock0_1 (however, that then won't work for ubifs, thus the auto-probing patches).
... OH!
Well, I needed some extra intellectual clubbing to catch on.
NOW I remember reading the UBI docs, about glubi, the fact that volumes are char devices, and I even seem to remember some ALL CAPS red size-20+ text at the top of the page saying something about it.
Tomorrow I'll go read the docs again, because I know I remember reading that you could put a RO-squashfs in a UBI volume. I just need to have it mounted the right way.
Hi J,
On Thu, Aug 11, 2016 at 06:15:32AM -0700, J Mo wrote:
On 08/11/2016 05:31 AM, Daniel Golle wrote:
That's what I told you in the previous mail, removing the rootfs= parameter from the dts should do the trick, because you just cannot mount a ubi device (which is a character device in Linux) with a block-based filesystem (like squashfs). This cannot and won't ever work and you could either leave it to OpenWrt/LEDE's auto-probing to figure out what to do based on the rootfs type (non-ubifs vs. ubifs) or append even more board- and filesystem-specific crap to your cmdline such as ubiblock=... root=/dev/ubiblock0_1 (however, that then won't work for ubifs, thus the auto-probing patches).
... OH!
Well, I needed some extra intellectual clubbing to catch on.
NOW I remember reading the UBI docs, about glubi, the fact that volumes are char devices, and I even seem to remember some ALL CAPS red size-20+ text at the top of the page saying something about it.
Tomorrow I'll go read the docs again, because I know I remember reading that you could put a RO-squashfs in a UBI volume. I just need to have it mounted the right way.
Exactly. However, this makes mounting a UBIFS volume entirely different from mounting a volume with any other (read-only) filesystem which needs a ubiblock device (gluebi has been deprecated in favour of ubiblock) to be created and subsequently mounted. The idea of the auto-probing patches [1] was to keep things filesystem- agnostic, ie. allow for either a single read-write UBIFS rootfs or any read-only filesystem (e.g. squashfs) which needs ubiblock and have a UBIFS read-write overlay on top. In this way, all you have to take care of is *not* to have any rootfs= or ubi* parameters in your kernel cmdline and all the rest should happen automagically.
Cheers
Daniel
Hello Richard,
Am 11.08.2016 um 11:51 schrieb Richard Weinberger:
Hi!
On Thu, Aug 11, 2016 at 4:26 AM, J Mo jmomo@jmomo.net wrote:
I tried re-flashing my UBI and tftpbooting my kernel before u-boot could ever get a chance to mangle it, and now I get much further, though I'm still not able to mount my rootfs for unknown reasons:
[ 3.772502] ubi0: attaching mtd11 [ 3.826477] UBI: EOF marker found, PEBs from 40 will be erasedWTF is this? Reading the corresponding patch makes me very sad.
[ 3.826638] ubi0: scanning is finished [ 3.872936] ubi0: volume 2 ("rootfs_data") re-sized from 9 to 430LEBs [ 3.873734] ubi0: attached mtd11 (name "rootfs", size 64 MiB) [ 3.878347] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [ 3.884234] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [ 3.890936] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [ 3.897849] ubi0: good PEBs: 512, bad PEBs: 0, corrupted PEBs: 0 [ 3.904627] ubi0: user volume: 3, internal volumes: 1, max. volumes count: 128 [ 3.910815] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 2142265782 [ 3.917902] ubi0: available PEBs: 0, total reserved PEBs: 512, PEBs reserved for bad PEB handling: 40 [ 3.927275] ubi0: background thread "ubi_bgt0d" started, PID 54 [ 3.937007] block ubiblock0_1: created from ubi0:1(rootfs) [ 3.942096] hctosys: unable to open rtc device (rtc0) [ 3.956528] VFS: Cannot open root device "ubi0:rootfs" or unknown-block(31,11): error -2 [ 3.956556] Please append a correct "root=" boot option; here are the available partitions:
Any advice on this? Any background information that I can read up on? My google searches have not come up with much. Ram knew about this, but I don't know if it's otherwise a known issue.
The process works fine on the OEM system, so I assume this is some ubinize format change which is incompatible with the older u-boot. Or, the newer kernel code doesn't know how to deal with the UBI once the older u-boot has mangled/attached it.
Seems like a backwards incompatibility issue.
Since OpenWRT/LEDE folks did more or less a hard fork of UBI I'm ignoring this issue.
Ufff.... thanks for this info!
If you encounter something like that using vanilla UBI I'm all ears.
That said, I kind of understand that you, OpenWRT/LEDE, have a pile of patches for auto probing rootfs and other runtime stuff but touching the UBI on-flash format is beyond funny. Doing so opens a can of worms and is painful for all parties. There are customers which build their products using OpenWrt and when they change the kernel at some point it will get nasty.
This situation needs to be improved now. I invite you to discuss this changes here on linux-mtd. Especially the stuff where you change the on-flash format. If UBI, or MTD in general, can do a better job in some areas, please tell such that a decent solution can be found. But your ad-hoc hacks need to stop.
Full Ack.
bye, Heiko
It's all moot now! I accidentally wrecked my u-boot today.
I typoed "nand write ${fileaddr} ${BOOTCONFIG_nand_addr} ${0x800}"
When I meant "0x800" instead of the undefined "${0x800}", which u-boot translated to 0xacc0000.
I guess I'm going to find out if that JTAG header works.
participants (4)
-
Daniel Golle -
Heiko Schocher -
J Mo -
Richard Weinberger