ubi and u-boot
[apologies for the cross post]
Is anyone working on ubi/ubifs support in u-boot?
Kind regards,
Bernard.
Quoted 3 lines · Bernard Blackham
[apologies for the cross post]
Is anyone working on ubi/ubifs support in u-boot?
I am not aware of anyone actively working on porting UBI to upstream U-Boot at this exact moment.
josh
Quoted 6 lines · Josh Boyer
Quoted 2 lines · Bernard Blackham
[apologies for the cross post]
Is anyone working on ubi/ubifs support in u-boot?I am not aware of anyone actively working on porting UBI to upstream U-Boot at this exact moment.
Is it even a good idea? The UBI (version 1 :-) initial scan is not fast for large flash, and if the bootloader does it too, that's twice as much time to boot.
However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
-- Jamie
Quoted 6 lines · Jamie Lokier
Quoted 3 lines · Josh Boyer
Quoted 1 line
Is anyone working on ubi/ubifs support in u-boot?
I am not aware of anyone actively working on porting UBI to upstream U-Boot at this exact moment.
Is it even a good idea?
From what I've seen, UBI is the first solution with the potential for
reliably booting from NAND flash - specifically, dealing with read-disturbance from adjacent blocks causing bit errors in critical boot blocks. This could save useful things like your kernel image (where it's rarely written, but it and blocks around it are read often enough to cause an annoying bitflip or two). The rewriting can be done once userspace boots, but having it in UBI to begin with makes this easier.
(Unless there's a much easier way to deal with read-disturbance that I've missed, in which case please lart me).
Wolfgang showed some interest briefly too.[1]
Quoted 6 lines
The UBI (version 1 :-) initial scan is not
fast for large flash, and if the bootloader does it too, that's twice as much time to boot.However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
If there's no compelling reasons not to, I'll try and find some time to work on ubi in uboot. I'm not expecting it to be easy though :)
Cheers,
Bernard.
[1] http://article.gmane.org/gmane.comp.boot-loaders.u-boot/32602
Quoted 2 lines · In message <[email protected]> you wrote:
Wolfgang showed some interest briefly too.[1]
I am definitely interested.
Quoted 3 lines
Quoted 3 lines
The UBI (version 1 :-) initial scan is not
fast for large flash, and if the bootloader does it too, that's twice as much time to boot.
We have the same (at at least similar) problems when using JFFS2 file systems in U-Boot. Yet, being able to do this is quite useful in many situations.
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However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
That would be of course a good thing to have :-)
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If there's no compelling reasons not to, I'll try and find some time to work on ubi in uboot. I'm not expecting it to be easy though :)
Thanks in advance, and good luck!
Best regards,
Wolfgang Denk
Signature · 6 lines
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de All these theories, diverse as they are, have two things in common: they explain the observed facts, and they are completeley and utterly wrong. - Terry Pratchett, _The Light Fantastic_
Quoted 5 lines · Wolfgang Denk
Quoted 2 lines · In message <[email protected]> you wrote:
Wolfgang showed some interest briefly too.[1]
I am definitely interested.
What I would suggest to start with is to teach U-boot to erase flash and preserve erase counters, because now it just wipes the erase counters out. Also, it would be nice to teach it to flash images properly in case of NAND flash.
I've just written a documentation section which I hope would help to do this. Please, see
http://www.linux-mtd.infradead.org/doc/ubi.html#L_format
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)
Quoted 12 lines · Artem Bityutskiy
Quoted 5 lines · Wolfgang Denk
Quoted 2 lines · In message <[email protected]> you wrote:
Wolfgang showed some interest briefly too.[1]
I am definitely interested.
What I would suggest to start with is to teach U-boot to erase flash and preserve erase counters, because now it just wipes the erase counters out. Also, it would be nice to teach it to flash images properly in case of NAND flash.
I was under the impression from past emails on the MTD list that the internal meta format for UBI has changed a few times over its lifetime.
Assuming this continues, I would think this would cause problems for bootloaders such as U-Boot whose flash partitions are not necessarily rewritten in the case of a product upgrade - i.e. a firmware upgrade with a new kernel would have a new UBI implementation and spec causing an older bootloader to fail to operate properly with the newer image.
/Ricard
--
Ricard Wolf Wanderl?f ricardw(at)axis.com Axis Communications AB, Lund, Sweden www.axis.com Phone +46 46 272 2016 Fax +46 46 13 61 30
Quoted 15 lines · Ricard Wanderlof
Quoted 12 lines · Artem Bityutskiy
Quoted 5 lines · Wolfgang Denk
Quoted 2 lines · In message <[email protected]> you wrote:
Wolfgang showed some interest briefly too.[1]
I am definitely interested.
What I would suggest to start with is to teach U-boot to erase flash and preserve erase counters, because now it just wipes the erase counters out. Also, it would be nice to teach it to flash images properly in case of NAND flash.
Quoted 8 lines
I was under the impression from past emails on the MTD list that the internal meta format for UBI has changed a few times over its lifetime.
Assuming this continues, I would think this would cause problems for bootloaders such as U-Boot whose flash partitions are not necessarily rewritten in the case of a product upgrade - i.e. a firmware upgrade with a new kernel would have a new UBI implementation and spec causing an older bootloader to fail to operate properly with the newer image.
I think there was only 1 time the on-flash format changed, and that was before UBI was merged upstream. New features can be introduced with additional flags, however older versions should be able to ignore those.
Artem, is that right? My memory is fuzzy here.
josh
Quoted 5 lines · Josh Boyer
I think there was only 1 time the on-flash format changed, and that was before UBI was merged upstream. New features can be introduced with additional flags, however older versions should be able to ignore those.
Artem, is that right? My memory is fuzzy here.
No, this is not right. We never changed the media format since UBI was merged.
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)
Quoted 9 lines · Artem Bityutskiy
Quoted 5 lines · Josh Boyer
I think there was only 1 time the on-flash format changed, and that was before UBI was merged upstream. New features can be introduced with additional flags, however older versions should be able to ignore those.
Artem, is that right? My memory is fuzzy here.
No, this is not right. We never changed the media format since UBI was merged.
Err, I meant what you said is right, but it is not right that we changed media format.
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)
Quoted 8 lines · Artem Bityutskiy
Quoted 5 lines · Josh Boyer
I think there was only 1 time the on-flash format changed, and that was before UBI was merged upstream. New features can be introduced with additional flags, however older versions should be able to ignore those.
Artem, is that right? My memory is fuzzy here.
[...] We never changed the media format since UBI was merged.
Ok, that sounds reassuring. I think I've been confusing UBI with UBIFS in this respect.
/Ricard
--
Ricard Wolf Wanderl?f ricardw(at)axis.com Axis Communications AB, Lund, Sweden www.axis.com Phone +46 46 272 2016 Fax +46 46 13 61 30
[U-Boot-Users] How to set CPU speed to 266mhz s3c2410?
In reply to Josh BoyerSorry for the newb question but I've been googling like mad and can't find any clues (or more likely, can't understand what I do find).
I'm looking at speed.c under /cpu/arm920t/s3c24xx and thinking this is the business end of CPU speed setting. I've been greping the source to see if I can track back to something calling them that I can understand, but no luck.
Any kind soul out there able to tell me how?
[U-Boot-Users] How to set CPU speed to 266mhz s3c2410?
Hi,
Quoted 8 lines · p wrote:
Sorry for the newb question but I've been googling like mad and can't find any clues (or more likely, can't understand what I do find).
I'm looking at
speed.cunder /cpu/arm920t/s3c24xx and thinking this is the business end of CPU speed setting. I've been greping the source to see if I can track back to something calling them that I can understand, but no luck.
under your board/<boardname>/<boardfile> Take for example the board/smdk2410/smdk2410.c and change
#if FCLK_SPEED==0 /* Fout = 203MHz, Fin = 12MHz for Audio */
#define M_MDIV 0xC3 #define M_PDIV 0x4 #define M_SDIV 0x1
Regards Michael
[U-Boot-Users] How to set CPU speed to 266mhz s3c2410?
In reply to pHi p,
u-boot-users-bounces at lists.sourceforge.net wrote on Tuesday, April 22, 2008 3:10 AM:
Quoted 5 lines
Sorry for the newb question but I've been googling like mad and can't find any clues (or more likely, can't understand what I do find).
I'm looking at
speed.cunder /cpu/arm920t/s3c24xx and thinking this is the business end of CPU speed setting. I've been greping the source to
No, in /cpu/arm920t/s3c24x0/speed.c are only functions to read the clock configuration. The setting of the clocks is done in the board specific initilaisation code. For the SMDK2410 for example in /board/smdk2410/smdk2410.c. The MPLL Clock (and thus the derived CPU clock FCLK) is configured via the PLL divider values MDIV, PDIV and SDIV. For a detailed description take a look into the S3C2410 datasheet (search for the MPLL register in the chapter Clock & Power Management).
Regards,
Martin Krause
--
TQ-Systems GmbH
Muehlstrasse 2, Gut Delling, D-82229 Seefeld
Amtsgericht Muenchen, HRB 105 018, UST-IdNr. DE 811 607 913
Geschaeftsfuehrer: Dipl.-Ing. (FH) Detlef Schneider, Dipl.-Ing. (FH) Ruediger Stahl
http://www.tq-group.com
[U-Boot-Users] How to set CPU speed to 266mhz s3c2410?
In reply to pThanks very much for the responses. Once it was pointed out to me that the CPU speed settings are in the board file I actually remembered seeing them there before. Don't know why I got fixated on that speed.c.
I'm now zipping along at 266 mhz!
Quoted 5 lines · On Mon, 2008-04-21 at 18:09 -0700, p wrote:
Sorry for the newb question but I've been googling like mad and can't find any clues (or more likely, can't understand what I do find).
I'm looking at
speed.cunder /cpu/arm920t/s3c24xx and thinking this is the business end
Quoted 9 lines · Josh Boyer
Quoted 8 lines
I was under the impression from past emails on the MTD list that the internal meta format for UBI has changed a few times over its lifetime.
Assuming this continues, I would think this would cause problems for bootloaders such as U-Boot whose flash partitions are not necessarily rewritten in the case of a product upgrade - i.e. a firmware upgrade with a new kernel would have a new UBI implementation and spec causing an older bootloader to fail to operate properly with the newer image.
Quoted 3 lines
I think there was only 1 time the on-flash format changed, and that was before UBI was merged upstream. New features can be introduced with additional flags, however older versions should be able to ignore those.
Quite. As long as the format is changed in an upward compatible way, it should be fine. Hopefully the existing format is designed to ensure that's always possible - at least for everything called 'UBI 1' since the upstream merge.
-- Jamie
Quoted 11 lines · Jamie Lokier
Quoted 6 lines · Josh Boyer
Quoted 2 lines · Bernard Blackham
[apologies for the cross post]
Is anyone working on ubi/ubifs support in u-boot?I am not aware of anyone actively working on porting UBI to upstream U-Boot at this exact moment.
Is it even a good idea? The UBI (version 1 :-) initial scan is not fast for large flash, and if the bootloader does it too, that's twice as much time to boot.
It's a good idea, yes. Particularly if you want to boot from NAND flash.
Can you define "large device"? It only scans the first 1 or 2 pages for each eraseblock to build up the volume tables. That really isn't that slow...
Quoted 2 lines
However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
Maybe. I was never fully convinced of that.
josh
Quoted 10 lines · Josh Boyer
Quoted 3 lines
Is it even a good idea? The UBI (version 1 :-) initial scan is not fast for large flash, and if the bootloader does it too, that's twice as much time to boot.
It's a good idea, yes. Particularly if you want to boot from NAND flash.
Can you define "large device"? It only scans the first 1 or 2 pages for each eraseblock to build up the volume tables. That really isn't that slow...
I was thinking this:
Hamish Moffatt wrote (Message-ID: <[email protected]>):
Quoted 2 lines
Sorry I should've said 512MiB perhaps: 512 megabytes. UBI attach time appears to be about 6 seconds.
If 6 seconds is as fast as it can be done, annoying but fair enough.
Adding _another_ 6 seconds to the boot time seems a lot to me.
The only ways I see to improve the speed in general are:
1. Partition the NAND into multiple independent UBIs, so the boot loader doesn't have the scan the whole chip, but that is obviously not so good for wear levelling. (It's probably alright, though, if it's like the /boot partition on a standard Linux distro - not updated very often.)
2. Change UBI's data structure so that the number of pages it needs to read is a sub-linear function of the number of erase blocks. I think this is what's meant by 'UBI 2'.
To remove the double scan:
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However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
Maybe. I was never fully convinced of that.
I can understand the hesitation, but I think 6 seconds just to find the kernel - especially when doing a 'disk resume' - is quite a lot.
Note that I haven't tried UBI myself yet. I'm going on what has been written to the list so far, as quoted above.
-- Jamie
Quoted 12 lines · Jamie Lokier
Quoted 10 lines · Josh Boyer
Quoted 3 lines
Is it even a good idea? The UBI (version 1 :-) initial scan is not fast for large flash, and if the bootloader does it too, that's twice as much time to boot.
It's a good idea, yes. Particularly if you want to boot from NAND flash.
Can you define "large device"? It only scans the first 1 or 2 pages for each eraseblock to build up the volume tables. That really isn't that slow...
Quoted 7 lines
I was thinking this:
Hamish Moffatt wrote (Message-ID: <[email protected]>):
Quoted 2 lines
Sorry I should've said 512MiB perhaps: 512 megabytes. UBI attach time appears to be about 6 seconds.
If 6 seconds is as fast as it can be done, annoying but fair enough.
You should read that thread a bit more carefully. The scan time is highly dependent upon the NAND driver beneath UBI. For example, a UBI scan/attach on a 1GiB device on OLPC was 2 seconds.
Quoted 2 lines
Adding _another_ 6 seconds to the boot time seems a lot to me.
You mean adding another "X amount of time depending on factors outside of UBI's control."
Quoted 14 lines
The only ways I see to improve the speed in general are:
1. Partition the NAND into multiple independent UBIs, so the boot loader doesn't have the scan the whole chip, but that is obviously not so good for wear levelling. (It's probably alright, though, if it's like the /boot partition on a standard Linux distro - not updated very often.)
2. Change UBI's data structure so that the number of pages it needs to read is a sub-linear function of the number of erase blocks. I think this is what's meant by 'UBI 2'.
To remove the double scan:
Quoted 7 lines
Quoted 4 lines
Quoted 2 lines
However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
Maybe. I was never fully convinced of that.
I can understand the hesitation, but I think 6 seconds just to find the kernel - especially when doing a 'disk resume' - is quite a lot.
You should really stop quoting this 6 second number.
Anyway, passing the scan results from a bootloader becomes very involved. You have to store it somewhere, probably preserving a section of DRAM, which isn't always easy.
Quoted 2 lines
Note that I haven't tried UBI myself yet. I'm going on what has been written to the list so far, as quoted above.
Maybe you should try it :).
josh
Quoted 9 lines · Josh Boyer
Quoted 5 lines
Hamish Moffatt wrote (Message-ID: <[email protected]>):
Quoted 2 lines
Sorry I should've said 512MiB perhaps: 512 megabytes. UBI attach time appears to be about 6 seconds.
If 6 seconds is as fast as it can be done, annoying but fair enough.
You should read that thread a bit more carefully. The scan time is highly dependent upon the NAND driver beneath UBI. For example, a UBI scan/attach on a 1GiB device on OLPC was 2 seconds.
Ah, I intended to quote the 2 seconds too but forgot, sorry. I think 2 seconds per gigabyte is a significant time, too, but not so much.
The followup suggested it was due to the speed of the chip, not so much the driver.
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Adding _another_ 6 seconds to the boot time seems a lot to me.
You mean adding another "X amount of time depending on factors outside of UBI's control."
Well, yes, that would be a reason to consider whether doing it is a good idea :-)
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I can understand the hesitation, but I think 6 seconds just to find the kernel - especially when doing a 'disk resume' - is quite a lot.
You should really stop quoting this 6 second number.
Let's call it 2 seconds per gigabyte, then.
Quoted 4 lines
Quoted 2 lines
Note that I haven't tried UBI myself yet. I'm going on what has been written to the list so far, as quoted above.
Maybe you should try it :).
I will when good looking figures are being quoted on the list ;-)
-- Jamie
Quoted 9 lines · Jamie Lokier
I was thinking this:
Hamish Moffatt wrote (Message-ID: <[email protected]>):
Quoted 2 lines
Sorry I should've said 512MiB perhaps: 512 megabytes. UBI attach time appears to be about 6 seconds.
If 6 seconds is as fast as it can be done, annoying but fair enough.
Adding _another_ 6 seconds to the boot time seems a lot to me.
Yes. I have a prototype system here booting a minimal system from NOR flash then booting the full system from NAND via kexec. I'm suffering my 6 seconds of UBI attach time twice each boot.
Six seconds does seem to be abnormal though - I don't have a hardware NAND controller so it's all software ECC, GPIO for chip selects etc. The performance is said to be much better with a hardware controller.
Quoted 4 lines
To remove the double scan:
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However, if there was a protocol for bootloader to pass the scan results to the booted kernel, that would be very nice.
That would certainly help my case. Fortunately my device is usually always-on and therefore boot time is not critical, and we don't suspend/resume.
Hamish
Signature · 1 line
Hamish Moffatt VK3SB <[email protected]> <[email protected]>
Quoted 3 lines · Bernard Blackham
[apologies for the cross post]
Is anyone working on ubi/ubifs support in u-boot?
Someone mailed me some question and he said he is trying to make u-boot UBI-aware, but that guy has not showed up anymore.
Yeah, it would be nice to have u-boot understand UBI. At leaset, it would be nice to teach it to preserve erase counters when erasing flash.
Signature · 2 lines
Best regards, Artem Bityutskiy (Битюцкий Артём)