Thanks Andre, This will be really a big help. Also, I am sure it will help anyone who will be working over SD card/MMC interface in Raspberry pi for RTEMS.
Currently, since I don't have enough knowledge on SD spec. I am going through the pdf that you have sent and trying to just initialize SD card on raspberry pi. Later I will try to read the block/sectors on SD card. Thanks & Regards Ritesh On Tue, Aug 26, 2014 at 1:34 PM, Andre Marques < andre.lousa.marq...@gmail.com> wrote: > Hello Ritesh, > > My progress on the SD card support can be found on > > https://bitbucket.org/asuol/rtems-graduation-project/src/ > > It contains the sources and a test case (it reads a file and write another > on the card), as well as patches so you can easily test that code. > > It was based on > > https://github.com/jncronin/rpi-boot/blob/master/emmc.c > > and right now it may or may not work with your SD card. I got it working > with the SD card I have used during development (4GB class 4 SanDisk SD > card), but it does not work with the card I have now (Kingston 8GB microSD > card on a SD adapter). I suspect this is related with the timeout the > driver gives for each command to complete in, as it is an hard coded value > which should be calculated by parsing the card's CSD register. Also the > code needs some major cleanup, and some features were overlooked such as > memory barriers. > > As for SD card documentation I have used the v3 simplified specifications > > SD host controller - > https://www.sdcard.org/downloads/pls/simplified_specs/archive/partA2_300.pdf > > SD physical layer - > https://www.sdcard.org/downloads/pls/simplified_specs/archive/part1_301.pdf > > Besides the broadcom datasheet. > > By the way, since you replied to this thread I am not sure if I ever > shared why it was hanging. Turns out that there was/is a conflict between > my emmc driver and the raspberry pi clock driver. All I had to do was to > disable the clock driver for it to work. > > --André Marques. > > > On 08/26/14 06:38, Ritesh Harjani wrote: > > Hi Andre, > > 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. > 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. > > > Thanks for the help!! > Ritesh > > > On Wed, May 14, 2014 at 12:30 AM, Andre Marques < > andre.lousa.marq...@gmail.com> wrote: > >> On 05/13/14 12:15, Andrey Mozzhuhin wrote: >> >> Do you not forget to call rtems_blkdev_request_done in read routine of >> block device driver? >> Also try to increase CONFIGURE_MAXIMUM_TASKS - bdbuf need some worker >> tasks. >> >> >> 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. >> >> >> >> >> https://github.com/jncronin/rpi-boot/blob/master/emmc.c >> >> 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. >> >> >> 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*). >> >> >> >> >> Not sure how to approach this problem, as the logic seems right. Will >> do more testing in the meanwhile. >> >> >> Today I have re-formated the card (under Linux), and the block data read >> on RPi checks with the card hexdump on Linux. >> >> So far I tested: >> >> - 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) >> >> - The request buffer contents ( >> http://www.rtems.org/onlinedocs/doxygen/cpukit/html/structrtems__blkdev__sg__buffer.html). >> Looking at this I don't know what the User pointer is. I'm using the buffer >> pointer to store my readings. >> >> - 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. >> >> - Tried also a busy wait between block readings. >> >> The result is always the same: when mounting the card partition, it reads >> the first two partition blocks and then hangs. >> >> >> If you get stuck share your sources and let me know. >> >> >> Will try to get the code to github soon. >> >> >> >> >> 2014-05-13 14:03 GMT+04:00 Andre Marques <andre.lousa.marq...@gmail.com>: >> >>> On 05/12/14 19:25, Andrey Mozzhuhin wrote: >>> >>> I think you need start with simple tests without file systems and >>> block device driver. >>> Try read and write blocks with known patterns and check it on PC and >>> Raspberry Pi. >>> >>> >>> 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. >>> >>> Not sure how to approach this problem, as the logic seems right. Will do >>> more testing in the meanwhile. >>> >>> >>> What are you use for MMC/SD protocol? Can I see it and block device >>> driver somewhere? >>> >>> >>> I'm porting the following code >>> >>> https://github.com/jncronin/rpi-boot/blob/master/emmc.c >>> >>> and using the following SD card documentation >>> >>> Physical Layer Simplified Specification (3.01) - >>> https://www.sdcard.org/downloads/pls/simplified_specs/archive/part1_301.pdf >>> >>> Host Controller Simplified Specification (2.00) - >>> https://www.sdcard.org/downloads/pls/simplified_specs/archive/partA2_200.pdf >>> >>> and the raspberry soc datasheet: Broadcom BCM2835 Peripherals Guide >>> (Chapter 5 - EMMC) >>> >>> >>> >>> 2014-05-12 20:23 GMT+04:00 Andre Marques <andre.lousa.marq...@gmail.com> >>> : >>> >>>> Hello, >>>> >>>> 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. >>>> >>>> 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. >>>> >>>> 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. >>>> >>>> I guess my driver is having some reading problems. >>>> >>>> >>>> On 05/05/14 19:30, Andrey Mozzhuhin wrote: >>>> >>>> You can try to use SD Card in opposite direction: >>>> 0) fill SD Card with zeroes; >>>> 1) format partition under RTEMS with msdos_format() function; >>>> 2) check that PC can read/write this SD Card; >>>> 3) if PC fails to mount this partition - dump SD Card and check that >>>> all data is on right sectors. >>>> >>>> >>>> >>>> 2014-05-05 22:28 GMT+04:00 Andrey Mozzhuhin <nops...@gmail.com>: >>>> >>>>> Hi, Andre >>>>> >>>>> You can try to use SD Card in opposite direction: >>>>> 0) fill SD Card with zeroes; >>>>> 1) format partition under RTEMS with msdos_format() function; >>>>> 2) check that PC can read/write this SD Card; >>>>> 3) if PC fails to mount this partition - dump SD Card and check that >>>>> all data is on right sectors. >>>>> >>>>> >>>>> >>>>> 2014-05-05 13:52 GMT+04:00 Andre Marques < >>>>> andre.lousa.marq...@gmail.com>: >>>>> >>>>> Hello, >>>>>> >>>>>> Following the problem in >>>>>> >>>>>> http://www.rtems.org/pipermail/rtems-devel/2014-April/006585.html >>>>>> >>>>>> I am now trying to mount the SD card partitions on RTEMS. >>>>>> >>>>>> Summarizing the process: >>>>>> >>>>>> 1. rtems_io_register_driver (by calling my driver with >>>>>> CONFIGURE_APPLICATION_EXTRA_DRIVERS on hello sample) >>>>>> >>>>>> 2. rtems_filesystem_make_dev_t (to get the device file) >>>>>> >>>>>> 3. rtems_disk_io_initialize >>>>>> >>>>>> 4. rtems_disk_create_phys (to create the disk, at /dev/sdc0) >>>>>> >>>>>> 5. rtems_bdpart_register_from_disk (to read and register the >>>>>> partitions) >>>>>> >>>>>> 6. rtems_fsmount (to mount the partitions) >>>>>> >>>>>> For rtems_fsmount I am providing the following fs_table: >>>>>> >>>>>> rtems_fstab_entry fs_table [] = { >>>>>> { >>>>>> .source = "/dev/sdc0", >>>>>> .target = "/mnt/p1", >>>>>> .type = "dosfs", >>>>>> .options = RTEMS_FILESYSTEM_READ_WRITE, >>>>>> .report_reasons = RTEMS_FSTAB_ANY, >>>>>> .abort_reasons = RTEMS_FSTAB_OK >>>>>> },{ >>>>>> .source = "/dev/sdc01", >>>>>> .target = "/mnt/p2", >>>>>> .type = "dosfs", >>>>>> .options = RTEMS_FILESYSTEM_READ_WRITE, >>>>>> .report_reasons = RTEMS_FSTAB_ANY, >>>>>> .abort_reasons = RTEMS_FSTAB_NONE >>>>>> } >>>>>> }; >>>>>> >>>>>> The SD card has only one partition starting at block number 8192. >>>>>> >>>>>> After I call rtems_fsmount it calls my driver to read block 8192 and >>>>>> 8193 and then hangs. >>>>>> >>>>>> I have tested the driver and It seems to have no problem reading >>>>>> single or multiple blocks. >>>>>> >>>>>> Any tips? >>>>>> >>>>>> Also I am using the following confdefs configuration (some values are >>>>>> exaggerated): >>>>>> >>>>>> #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER >>>>>> #define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER >>>>>> #define CONFIGURE_APPLICATION_NEEDS_LIBBLOCK >>>>>> >>>>>> #define CONFIGURE_FILESYSTEM_DOSFS >>>>>> #define CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM >>>>>> >>>>>> #define CONFIGURE_APPLICATION_EXTRA_DRIVERS SD_CARD_DRIVER_TABLE_ENTRY >>>>>> >>>>>> #define CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS 20 >>>>>> >>>>>> #define CONFIGURE_MAXIMUM_TASKS 2 >>>>>> #define CONFIGURE_MAXIMUM_DRIVERS 10 >>>>>> >>>>>> #define CONFIGURE_RTEMS_INIT_TASKS_TABLE >>>>>> >>>>>> #define CONFIGURE_INIT_TASK_STACK_SIZE (32 * 1024) >>>>>> >>>>>> #define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION >>>>>> >>>>>> #define CONFIGURE_INIT >>>>>> >>>>>> --André Marques >>>>>> >>>>>> _______________________________________________ >>>>>> rtems-devel mailing list >>>>>> rtems-de...@rtems.org >>>>>> http://www.rtems.org/mailman/listinfo/rtems-devel >>>>>> >>>>> >>>>> >>>> >>>> >>>> _______________________________________________ >>>> rtems-devel mailing >>>> listrtems-devel@rtems.orghttp://www.rtems.org/mailman/listinfo/rtems-devel >>>> >>>> >>>> >>> >>> >> >> >> _______________________________________________ >> rtems-devel mailing list >> rtems-de...@rtems.org >> http://www.rtems.org/mailman/listinfo/rtems-devel >> >> > >
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