GPT + EFI support

[GoogleCodeExporter]

Enable EFI and GPT (GUID Partition Table) support for the kernel. 

Need to recompile kernel with according flags (TomatoUSB firmware has support 
of such a thing).

EFI/GPT support should be implemented to connect hard disk with more than 2TB 
storage.

Original issue reported on code.google.com by andrey.l...@gmail.com on 15 Mar 2011 at 9:39

[GoogleCodeExporter]

First of all, you should clarify which FW branch you mean - 1.9.2.7-d (2.4 
kernel) or 1.9.2.7-rtn (2.6 kernel) ?

Second, can you tell will be CONFIG_EFI_PARTITION=y enough?

Original comment by lly.dev on 16 Mar 2011 at 7:37

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

I mean 1.9.2.7-rtn (2.6 kernel).
As far as I'm concerned, CONFIG_EFI_PARITION=y would be enough for that.

For more information you can look through
http://www.cyberciti.biz/tips/fdisk-unable-to-create-partition-greater-2tb.html
http://www.ibm.com/developerworks/linux/library/l-gpt/index.html

I can test firmware for GPT support, as it'll be implemented.

Original comment by andrey.l...@gmail.com on 16 Mar 2011 at 11:42

[GoogleCodeExporter]

Ok, but as I can understand you have to either to install fdisk from Optware, 
or to partition disk on PC, since GPT support in busybox turned off even on 
TomatoUSB. Am I right?

btw., why you need such big disk on router with very limited USB transfer speed?

Original comment by lly.dev on 16 Mar 2011 at 11:58

• Changed state: Accepted

[GoogleCodeExporter]

Yes, you're right. But disk partitioning is not a problem =)

I've lots of data to write there (GIS tiles). USB speed would be enough for me.

Original comment by andrey.l...@gmail.com on 16 Mar 2011 at 12:13

[GoogleCodeExporter]

Done in r2811

Original comment by lly.dev on 16 Mar 2011 at 8:04

• Changed state: Done

[GoogleCodeExporter]

Another thing needs to be added to kernel support. One need to enable 
CONFIG_LBDAF=y. The default value is [n].
LBDAF is Large Block Device and Files.

I've tested r2811 - it doesn't show correct values, so let's try enable LBDAF 
with EFI_PARTITION.

I took this information from
http://www.linux.org.ru/forum/linux-hardware/5708491
(судя по форуму, ты говоришь по-русски =))

Another thing - we can try enable LBDAF and disable EFI support.

I'll test it as it'll be implemented and I could download nightly build.

Original comment by andrey.l...@gmail.com on 17 Mar 2011 at 11:43

[GoogleCodeExporter]

Да, но инцинденты предпочитаем вести на 
английском, чтобы было понятно всем. Для 
дискуссий на русском есть wl500g.info

Unfortunately, we have to use obsolete 2.6.22 kernel and, probably, it has bugs 
in LBD (was renamed later to LBDAF) support.
So, let's try to test this feature before turn it for all. Can you compile 
firmware yourself? Which router model you use?

Original comment by lly.dev on 18 Mar 2011 at 8:02

[GoogleCodeExporter]

Tomato USB firmware uses 2.6 also, and they included EFI + LDB.

I can try to compile firmware, but it's quite difficult. I have lots of Unix 
VMs, but I don't know, if I have all the packages.

I use RT-N16 and I can test this feature.

Original comment by andrey.l...@gmail.com on 18 Mar 2011 at 12:07

[GoogleCodeExporter]

In other words, it(EFI + LDB) works in TomatoUSB?

Original comment by lly.dev on 18 Mar 2011 at 12:14

[GoogleCodeExporter]

I didn't test it, but according to 
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=519238&sid=b99186fcf9363333784fcd22
0c7f7586 it works fine.

If you e-mail me a version of firmware with LDB I'll test it ASAP.

Original comment by andrey.l...@gmail.com on 18 Mar 2011 at 1:36

[GoogleCodeExporter]

Please try http://wl500g.googlecode.com/files/RT-N16-1.9.2.7-rtn-r2823M.trx

Original comment by lly.dev on 18 Mar 2011 at 7:46

[GoogleCodeExporter]

It find only 2,2Tb of 3Tb storage. It seems to me that it wants to be MBR, 
instead of GPT.

But fdisk -l shows that the system is GPT.

Working around the problem...

Original comment by andrey.l...@gmail.com on 19 Mar 2011 at 10:58

[GoogleCodeExporter]

Probably, it's kernel bug. For example:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8f76
d151b010980d137bfdc736d1d8f64b489165 [SCSI] fix sign extension with 1.5TB 
usb-storage LBD=y

and more, more ...

Original comment by lly.dev on 19 Mar 2011 at 11:01

[GoogleCodeExporter]

Look at this commit for TomatoUSB firmware:
http://repo.or.cz/w/tomato.git/commit/3558a921c2c5fcb793e2def5cc86702318d72bba

Fedor changed Makefile also. 
Do we need to do the same?

I debugged through the 2823M firmware. Log says, that the disk has unknown 
partition table:
Jan  1 03:00:09 kernel:  sda: unknown partition table

Original comment by andrey.l...@gmail.com on 19 Mar 2011 at 5:18

[GoogleCodeExporter]

Sorry, I don't understand your suggestion. TomatoUSB Makefile has nothing with 
ours. But we use very similar kernels.

2823M has:
CONFIG_EFI_PARTITION=y
CONFIG_MSDOS_PARTITION=y
CONFIG_LBD=y

GPT partition should has 'EFI PART' signature, try investigate it on PC.

Original comment by lly.dev on 19 Mar 2011 at 5:45

[GoogleCodeExporter]

I found this thread while trying to connect my 3Tb hard drive to RT-N16. After 
building firmware with
CONFIG_EFI_PARTITION=y
CONFIG_MSDOS_PARTITION=y
CONFIG_LBD=y
linux kernel flags - it detected, mounted and works fine. fdisk on router won't 
work with this harddrive but this is not an issue for me. I partitioned HDD 
under Ubuntu to GPT, instead MBR.

I attached my firmware, may be it will be helpful for someone else.

Original comment by molind on 4 May 2012 at 10:01

Attachments:

• RT-N16-1.9.2.7-rtn-r4162.trx