mounting SD Card on uClinux

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Have you edited your dts file with mmc-spi-slot? See section 3.2 in my uClinux_nios2.pdf document.

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Hi, Thanks for your respond. I got it to work and thanks to Alex Hornung.

Problem:

1) device tree

spi_0: spi@0x140 {

compatible = "ALTR,spi-altera_avalon_spi", "ALTR,spi-1.0";

reg = < 0x00000140 0x00000020 >;

interrupt-parent = < &myCPU >;

interrupts = < 3 >;

/*# address-cells = < 1 >; */ <-comment out

/*# size-cells = < 0 >; */ <-comment out

mmc-spi@0 { <- make sure is named mmc-spi

compatible = "mmc-spi-slot";

spi-max-frequency = < 10000000 >;

reg = < 0x00000000 >;

voltage-ranges = < 3300 3300 >; <-missing important piece

}; //end mmc-slot@0

}; //end spi@0x140 (mmc_spi)

2) menuconfig - Make sure selection is [*] and not [M]

3) of_mmc_spi.c <-there is a bug

for (i = 0; i < num_ranges; i++) {

const int j = i * 2;

u32 mask;

u32 vdd_min = be32_to_cpu(voltage_ranges[j]);

u32 vdd_max = be32_to_cpu(voltage_ranges[j + 1]);

mask = mmc_vddrange_to_ocrmask(voltage_ranges[j],

voltage_ranges[j + 1]);

mask = mmc_vddrange_to_ocrmask(vdd_min, vdd_max);

if (!mask) {

ret = -EINVAL;

dev_err(dev, "OF: voltage-range# %d is invalid\n", i);

goto err_ocr;

}

oms->pdata.ocr_mask |= mask;

}

Hi

When i insert the SD card i get the below message and also can't mount the SD Card

root:/dev> mmc0: SD Status: Invalid Allocation Unit size.

mmc0: host does not support reading read-only switch. assuming write-enable.

mmc0: new SD card on SPI

mmcblk0: mmc0:0000 SD512 478 MiB

mmcblk0: p1

root:/dev> mount -t vfat /dev/mmcblk0 /mnt

mount: mounting /dev/mmcblk0 on /mnt failed: No such device

root:/dev> mount -t vfat /dev/mmcblk0p1 /mnt

mount: mounting /dev/mmcblk0p1 on /mnt failed: No such device

root:/dev>

I also format the sdcard with FAT32 and 512byte but it doesn't help

Please give me some suggestion to fix the problem

Hi,

It's a good sign if you see it detect the SD Card size. I am using a 2 GB SD Card so perhaps you may want to try a bigger size memory? Also, to make sure you enabled the [*] fat32 in file system doing kernel setup. I hope this help.

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Hi

When i insert the SD card i get the below message and also can't mount the SD Card

root:/dev> mmc0: SD Status: Invalid Allocation Unit size.

mmc0: host does not support reading read-only switch. assuming write-enable.

mmc0: new SD card on SPI

mmcblk0: mmc0:0000 SD512 478 MiB

mmcblk0: p1

root:/dev> mount -t vfat /dev/mmcblk0 /mnt

mount: mounting /dev/mmcblk0 on /mnt failed: No such device

root:/dev> mount -t vfat /dev/mmcblk0p1 /mnt

mount: mounting /dev/mmcblk0p1 on /mnt failed: No such device

root:/dev>

I also format the sdcard with FAT32 and 512byte but it doesn't help

Please give me some suggestion to fix the problem

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Hi, all.

May be, it's too late to answer, but my message may help someone in the future and one question still left regarding this topic.

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Please give me some suggestion to fix the problem

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Well, next step is definitely simple:

Lets look at the devices, configured in the system:

/#  cat /proc/devices
Character devices:
  1 mem
  2 pty
  3 ttyp
  4 ttyS
  5 /dev/tty
  5 /dev/console
  5 /dev/ptmx
 10 misc
128 ptm
136 pts
153 spi
204 ttyUL
Block devices:
  1 ramdisk
259 blkext
179 mmc <--- Got it!

OK, our MMC card is configured as block device and had major number 179.

/#  ls /sys/dev/block/ | grep 179
179:0
179:1

We see two devices with major = 179. The first one with minor number 0 is MMC (SD) card itself and the second with number 1 is the first (and last in my case) partition on the card.

The problem is that "ls /dev/" command shows nothing about MMC, but we can make device node manually via mknod command:

/#  mknod /dev/mmcblk0p1 b 179 1
/#  mount /dev/mmcblk0p1 /mnt/
/#  ls /mnt
simpleImage.xilinx.ub  vmlinux

Thats it!

Well, but I still do not know, how to make next step: say system to create /dev/mmcblk0p1 node automatically and have root partition on my SD card during boot.

Thanks all for this topic, it was helpful.

PS: Well, there was almost nothing magic.

On BB:

1. Format your SD card in ext2 or ext3.

2. Copy busybox content into SD

3. (For paranoics like me :) ) Create static node /dev/mmcblk0p1 on SD using mknod with major:minor numbers 179:1

4. [MAGIC] Edit kernel boot parameters with "root=/dev/mmcblk0p1" and (this is important!) "rootdelay=3".

The "rootdelay" parameter says kernel to wait until root partition initialization complete. Three seconds was enough in my case. [/MAGIC]

Thats all, folks. :)

Hello i am trying to implement SDCard in my DE2-115 and i've followed the steps described in the# 6 post. However i get this error in the linux boot process spi_altera: pobe of d000900.spi failed with error -16.

There appears to be a mmc in proc/devices though.

Any ideas? Can i use the default clock frequency of SPI 3 wire? I think it's 128khz.

Solved it! It was a problem with EPCS ADDRESS SPAM being too high, it was going in the SPI 3 wire address spam

I feel like it's really slow to read/write in the SDCard. It's formated with FAT file system and my NIOS2 is running at 100mhz.

Any tips?

Hi,

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I feel like it's really slow to read/write in the SDCard. It's formated with FAT file system and my NIOS2 is running at 100mhz.

Any tips?

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Please refer to the next,

http://www.alterawiki.com/wiki/linux_with_mmu_on_veek/t-pad

or

http://www.alteraforum.com/forum/showthread.php?t=25605

.

Kazu