<div dir="ltr">Hi Andre, <div><br></div><div>I am too trying to understand SD card/MMC protocol on Raspberry pi for RTEMS. You said in your last mail that you have already done some progress on this. </div><div>Could you please share your code at some place, so that others can get a help from your code in case anybody else too is trying to understand/develop SD card support for Raspberry pi. </div>
<div><br></div><div><br></div><div>Thanks for the help!!</div><div>Ritesh</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, May 14, 2014 at 12:30 AM, Andre Marques <span dir="ltr"><<a href="mailto:andre.lousa.marques@gmail.com" target="_blank">andre.lousa.marques@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"><div class="">
<div>On 05/13/14 12:15, Andrey Mozzhuhin
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>
<div>Do you not forget to call rtems_blkdev_request_done in
read routine of block device driver? <br>
</div>
Also try to increase CONFIGURE_MAXIMUM_TASKS - bdbuf need some
worker tasks.<br>
</div>
</div>
</blockquote>
<br></div>
I call rtems_blkdev_request_done after each read request, and
changing CONFIGURE_MAXIMUM_TASKS to 20 (instead of 2) did not had
any impact.<div class=""><br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div><br>
>> <a href="https://github.com/jncronin/rpi-boot/blob/master/emmc.c" target="_blank">https://github.com/jncronin/rpi-boot/blob/master/emmc.c</a><br>
<br>
</div>
<div>Hmm. Implementation specific to Raspberry Pi is not good
idea. It is better to separate MMC/SD protocol implementation
and hardware support like in FreeBSD or Linux.<br>
</div>
</div>
</blockquote>
<br></div>
Yes, the point in the end is probably to have the MMC/SD protocol
somewhere else, just like the spi-sd-card driver (SD card access
through SPI interface protocol, at c/src/libchip/i2c/spi-sd-card*).<div class=""><br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div><br>
>> Not sure how to approach this problem, as the logic
seems right. Will do more testing in the meanwhile.<br>
</div>
<br>
</div>
</blockquote>
<br></div>
Today I have re-formated the card (under Linux), and the block data
read on RPi checks with the card hexdump on Linux.<br>
<br>
So far I tested:<br>
<br>
- The block data that is being read, and compared with the same
block data read on Linux (small mismatch (4 bits) at the middle of a
512 byte block before, no mismatch now)<br>
<br>
- The request buffer contents
(<a href="http://www.rtems.org/onlinedocs/doxygen/cpukit/html/structrtems__blkdev__sg__buffer.html" target="_blank">http://www.rtems.org/onlinedocs/doxygen/cpukit/html/structrtems__blkdev__sg__buffer.html</a>).
Looking at this I don't know what the User pointer is. I'm using the
buffer pointer to store my readings.<br>
<br>
- Reading the partition table from the first block. I can read the
first block and register the card partition as a logical disk, so
reading and registering the partition table is no problem.<br>
<br>
- Tried also a busy wait between block readings.<br>
<br>
The result is always the same: when mounting the card partition, it
reads the first two partition blocks and then hangs.<div class=""><br>
<br>
<blockquote type="cite">
<div dir="ltr">If you get stuck share your sources and let me
know.<br>
<br>
</div>
</blockquote>
<br></div>
Will try to get the code to github soon.<div><div class="h5"><br>
<br>
<blockquote type="cite">
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">2014-05-13 14:03 GMT+04:00 Andre
Marques <span dir="ltr"><<a href="mailto:andre.lousa.marques@gmail.com" target="_blank">andre.lousa.marques@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>
<div>On 05/12/14 19:25, Andrey Mozzhuhin wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>I think you need start with simple tests
without file systems and block device driver.<br>
</div>
<div>
<div>Try read and write blocks with known patterns
and check it on PC and Raspberry Pi.<br>
<br>
</div>
</div>
</div>
</blockquote>
<br>
</div>
I have checked the data read by my emmc driver from the
first two blocks (the ones it reads) on the RPi, and
compared with an hexdump of those same two blocks on
Linux, and there is a small mismatch at the middle of the
first block.<br>
<br>
Not sure how to approach this problem, as the logic seems
right. Will do more testing in the meanwhile.
<div><br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div>
<div>What are you use for MMC/SD protocol? Can I
see it and block device driver somewhere?<br>
</div>
</div>
</div>
</blockquote>
<br>
</div>
I'm porting the following code<br>
<br>
<a href="https://github.com/jncronin/rpi-boot/blob/master/emmc.c" target="_blank">https://github.com/jncronin/rpi-boot/blob/master/emmc.c</a><br>
<br>
and using the following SD card documentation<br>
<br>
Physical Layer Simplified Specification (3.01) -
<a href="https://www.sdcard.org/downloads/pls/simplified_specs/archive/part1_301.pdf" target="_blank">https://www.sdcard.org/downloads/pls/simplified_specs/archive/part1_301.pdf</a><br>
<br>
Host Controller Simplified Specification (2.00) -
<a href="https://www.sdcard.org/downloads/pls/simplified_specs/archive/partA2_200.pdf" target="_blank">https://www.sdcard.org/downloads/pls/simplified_specs/archive/partA2_200.pdf</a><br>
<br>
and the raspberry soc datasheet: Broadcom BCM2835
Peripherals Guide (Chapter 5 - EMMC) <br>
<div>
<div> <br>
<blockquote type="cite">
<div dir="ltr">
<div>
<div> </div>
</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">2014-05-12 20:23
GMT+04:00 Andre Marques <span dir="ltr"><<a href="mailto:andre.lousa.marques@gmail.com" target="_blank">andre.lousa.marques@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hello,<br>
<br>
I have used the pc386 BSP to mount the
card (before your suggestions) using the
fileio sample and it could read the card
contents perfectly.<br>
<br>
Then I filled the card with zeros using dd
on Linux, modified the fileio sample to
format the card with msdos_format(dev,
NULL) and then mounted it on the pc 386
BSP fileio sample and I could write and
read the card.<br>
<br>
On Linux I set the card with the necessary
files for Raspberry, and when my driver
tries to mount the card on the Raspberry
Pi it reads the first 2 blocks (now 0 and
1, because the card has no partition
table) and hangs, just as before.<br>
<br>
I guess my driver is having some reading
problems.
<div>
<div><br>
<br>
On 05/05/14 19:30, Andrey Mozzhuhin
wrote:<br>
</div>
</div>
</div>
<div>
<div>
<blockquote type="cite">
<div dir="ltr">You can try to use SD
Card in <span lang="en"><span>opposite</span></span>
direction:<br>
<div>0) fill SD Card with zeroes;<br>
</div>
1) format partition under RTEMS with
msdos_format() function;<br>
2) check that PC can read/write this
SD Card;<br>
3) if PC fails to mount this
partition - dump SD Card and check
that all data is on right sectors.<br>
<div><br>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">2014-05-05
22:28 GMT+04:00 Andrey Mozzhuhin
<span dir="ltr"><<a href="mailto:nopscmn@gmail.com" target="_blank">nopscmn@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div>
<div>
<div>
<div>Hi, Andre<br>
<br>
</div>
You can try to use SD
Card in <span lang="en"><span>opposite</span></span>
direction:<br>
</div>
<div>0) fill SD Card
with zeroes;<br>
</div>
1) format partition
under RTEMS with
msdos_format() function;<br>
</div>
2) check that PC can
read/write this SD Card;<br>
</div>
3) if PC fails to mount this
partition - dump SD Card and
check that all data is on
right sectors.<br>
<div><br>
</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">2014-05-05
13:52 GMT+04:00 Andre
Marques <span dir="ltr"><<a href="mailto:andre.lousa.marques@gmail.com" target="_blank">andre.lousa.marques@gmail.com</a>></span>:
<div>
<div><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br>
<br>
Following the
problem in<br>
<br>
<a href="http://www.rtems.org/pipermail/rtems-devel/2014-April/006585.html" target="_blank">http://www.rtems.org/pipermail/rtems-devel/2014-April/006585.html</a><br>
<br>
I am now trying to
mount the SD card
partitions on RTEMS.<br>
<br>
Summarizing the
process:<br>
<br>
1.
rtems_io_register_driver
(by calling my
driver with
CONFIGURE_APPLICATION_EXTRA_DRIVERS
on hello sample)<br>
<br>
2.
rtems_filesystem_make_dev_t
(to get the device
file)<br>
<br>
3.
rtems_disk_io_initialize<br>
<br>
4.
rtems_disk_create_phys
(to create the disk,
at /dev/sdc0)<br>
<br>
5.
rtems_bdpart_register_from_disk
(to read and
register the
partitions)<br>
<br>
6. rtems_fsmount (to
mount the
partitions)<br>
<br>
For rtems_fsmount I
am providing the
following fs_table:<br>
<br>
rtems_fstab_entry
fs_table [] = {<br>
{<br>
.source =
"/dev/sdc0",<br>
.target =
"/mnt/p1",<br>
.type =
"dosfs",<br>
.options =
RTEMS_FILESYSTEM_READ_WRITE,<br>
.report_reasons
= RTEMS_FSTAB_ANY,<br>
.abort_reasons
= RTEMS_FSTAB_OK<br>
},{<br>
.source =
"/dev/sdc01",<br>
.target =
"/mnt/p2",<br>
.type =
"dosfs",<br>
.options =
RTEMS_FILESYSTEM_READ_WRITE,<br>
.report_reasons
= RTEMS_FSTAB_ANY,<br>
.abort_reasons
= RTEMS_FSTAB_NONE<br>
}<br>
};<br>
<br>
The SD card has only
one partition
starting at block
number 8192.<br>
<br>
After I call
rtems_fsmount it
calls my driver to
read block 8192 and
8193 and then hangs.<br>
<br>
I have tested the
driver and It seems
to have no problem
reading single or
multiple blocks.<br>
<br>
Any tips?<br>
<br>
Also I am using the
following confdefs
configuration (some
values are
exaggerated):<br>
<br>
#define
CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER<br>
#define
CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER<br>
#define
CONFIGURE_APPLICATION_NEEDS_LIBBLOCK<br>
<br>
#define
CONFIGURE_FILESYSTEM_DOSFS<br>
#define
CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM<br>
<br>
#define
CONFIGURE_APPLICATION_EXTRA_DRIVERS
SD_CARD_DRIVER_TABLE_ENTRY<br>
<br>
#define
CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS
20<br>
<br>
#define
CONFIGURE_MAXIMUM_TASKS
2<br>
#define
CONFIGURE_MAXIMUM_DRIVERS
10<br>
<br>
#define
CONFIGURE_RTEMS_INIT_TASKS_TABLE<br>
<br>
#define
CONFIGURE_INIT_TASK_STACK_SIZE
(32 * 1024)<br>
<br>
#define
CONFIGURE_INITIAL_EXTENSIONS
RTEMS_TEST_INITIAL_EXTENSION<br>
<br>
#define
CONFIGURE_INIT<br>
<br>
--André Marques<br>
<br>
_______________________________________________<br>
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</blockquote>
</div>
</div>
</div>
<br>
</div>
</blockquote>
</div>
<br>
</div>
</div>
<br>
<fieldset></fieldset>
<br>
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</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
</div>
</div>
</div>
</blockquote>
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<br>
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