Can I boot DM6446 from SDHC card?

Sumit Kumar

Hi,

I am using mv pro 4 kernel 2.6.10 on dm6446. I have applied the patch to support SDIO/SDHC. But the drivers built are dynamically loadable modules. It is working fine as dynamic modules but to boot from SDHC I have to make it a part of the kernel. Is it possible to built it as part of kernel? I tried but I am getting following error:

...

<3>Root-NFS: No NFS server available, giving up.

Root-NFS: No NFS server available, giving up.

<3>VFS: Unable to mount root fs via NFS, trying floppy.

VFS: Unable to mount root fs via NFS, trying floppy.

VFS: Cannot open root device "mmcblk0p1" or unknown-block(2,0)

VFS: Cannot open root device "mmcblk0p1" or unknown-block(2,0) Please append a correct "root=" boot option Please append a correct "root=" boot option <0>Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0) Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)

...

over 15 years ago

0 Sumit Kumar over 15 years ago

Prodigy 150 points

the bootargs is :

setenv bootargs video=davincifb:vid0=720x480x16,2500K:vid1=720x480x16,2500K:osd0=720x480x16,2025K ip=dhcp davinci_enc_mngr.ch0_output=COMPOSITE

davinci_enc_mngr.ch0_mode=ntsc rw noinitrd root=/dev/mmcblk0p1 rootfstype=ext3 mem=120M console=ttyS0,115200n81 rootwait

0 Sekhar Nori over 15 years ago

TI__Expert 6385 points

Hi Sumit,

I am afraid building SDHC support as part of the kernel is not supported. This is mentioned in the release notes of LSP 1.10 patch level 50 release:

The SDIO stack in its current form, does not allow the stack and and drivers to be built as part of the kernel. The drivers shall be built only as dynamically loadable kernel modules.

Also there no planned updates to MV Linux 2.6.10 release. Can you please consider using the latest PSP 3.x instead? The kernel included in this release supports SDHC natively.

Thanks,

Sekhar

0 Sumit Kumar over 15 years ago in reply to Sekhar Nori

Prodigy 150 points

Hi Sekhar,

Thanks for prompt reply. I had gone through that document. Still I was hoping that someone could have added kernel support for that. :-)

It's not possible for me to move to PSP 3.x as of now. Could you point me towards any document where they have added kernel support of SDIO/SDHC, so that I can try back porting it.

Regards,

Sumit

0 Sekhar Nori over 15 years ago in reply to Sumit Kumar

TI__Expert 6385 points

Hi Sumit,

Sumit Kumar said:
Could you point me towards any document where they have added kernel support of SDIO/SDHC, so that I can try back porting it.

Looks like the following commit added SDHC support. However, I am not sure how easy it is to port this to the MV 2.6.10 kernel.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fba68bd2dab1ac99af3c5a963ec9581cfa9f1725

Thanks,

Sekhar

0 Sumit Kumar over 15 years ago in reply to Sekhar Nori

Prodigy 150 points

Thanks for the pointer. I will try and get back.

-Sumit

0 Sumit Kumar over 15 years ago in reply to Sumit Kumar

Prodigy 150 points

Thanks Sekhar, it worked.

0 Joshua Hintze over 14 years ago in reply to Sumit Kumar

Intellectual 395 points

Hi Sumit,

I'm having the same issues. I was wondering if you could send me your 2.6.10 mmc drivers and headers or post somewhere or even just a little bit more description what you do.

Thanks

0 Sumit Kumar over 14 years ago in reply to Joshua Hintze

Prodigy 150 points

Hi Joshua,

I had simply diff the files in above mentioned location and files in my mmc directory. Replaced the changes with the suggested ones and it worked.

Regards,

Sumit

0 Joshua Hintze over 14 years ago in reply to Sumit Kumar

Intellectual 395 points

Thanks, Good,

The diff seems pretty trivial. However the only thing that doesn't quite fit well with the 2.6.10 is this

--- a/drivers/mmc/mmc.c

+++ b/drivers/mmc/mmc.c

@@ -289,7 +289,10 @@ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card,

else

limit_us = 100000;

- if (timeout_us > limit_us) {

+ /*

+ * SDHC cards always use these fixed values.

+ */

+ if (timeout_us > limit_us || mmc_card_blockaddr(card)) {

data->timeout_ns = limit_us * 1000;

data->timeout_clks = 0;

}

There isn't even an mmc_set_data_timeout(...) function in mmc.c in the 2.6.10. Hopefully I can get away with out it.

0 Sumit Kumar over 14 years ago in reply to Joshua Hintze

Prodigy 150 points

Hi,

mmc_set_data_timeout is used basically in mmc_read_scrs function. Just try to add that function call in mmc_read_scrs and try out. I don't have access to the ported code now so I can't check. Hopefully, this will resolve the issue.

Regards,

Sumit

0 Joshua Hintze over 14 years ago in reply to Sumit Kumar

Intellectual 395 points

It worked. Thank you.

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Can I boot DM6446 from SDHC card?