SD Card example design using standalone?

RE: SD Card example design using standalone?

jafoste4 — Mon, 23 Jan 2017 14:50:43 GMT

Hello Prathik4,

His post was from 4 years ago and looking at his GitHub, it hasn't been updated in over a year. The material you are looking for may be out of date.

--Josh

RE: SD Card example design using standalone?

prathik4 — Mon, 23 Jan 2017 06:50:24 GMT

Hi James,

Can you please tell how us to use the SDCard driver that you have built for reading and writing data to sd card.

Thanks in advance.

RE: SD Card example design using standalone?

Former Member — Sat, 24 Sep 2016 13:55:03 GMT

jameswalmsley, i am working with raspberry pi bare metal programming, i found your rpi-boot project very useful. i have few clarification from emmc.c

how do i use sdread and sdwrite functions?

what is the block device structure ?

how do i find block device values to the sd card?

it would be greate help if you explain me little bit. sample code also fine

thank you

RE: SD Card example design using standalone?

Former Member — Thu, 30 Apr 2015 02:10:52 GMT

Hi,

I realize this is a long time after your comment. But nevertheless.

1) I was wondering, if there is simply NO other connection to be made from the ZYNQ, except for the GPIO setting (and SD0 unsetting)?

2) How does the SD card get it's clock? I understand that E14 pin for the SD card provides the card. Will unchecking SD0 still provide a clock on this line?

3) Should I be using an axi_peripheral at all between my PS and the GPIO connection to the SD card?

Omkar

RE: SD Card example design using standalone?

Former Member — Mon, 13 Oct 2014 20:18:28 GMT

Here's a related topic:
http://zedboard.org/content/standalone-sd-card-sdio

RE: SD Card example design using standalone?

Former Member — Mon, 13 Oct 2014 18:26:59 GMT

Hi Jet,

Basically, you have to generate a block design containing a Zynq processor system in "Vivado". Then you export the implemented design to "Xilinx SDK". During the export a directory hw_platform_0 is created. Next you generate a new application project, e.g. hello_world. Using the defaults this will create a "hello world" program as well as a "hello_world.bsp" board support package which includes the initialization of the platform, init_platform() in the file platform.c. Next, you right-click on the source folder hello_world/src and select import -> General -> File System -> From directory. Here you select the directory with the SD card source files and import all *.h and *.c files. Remove the file helloworld.c and recompile, e.g. using Project -> Build all. From there on you can program the FPGA and run the main() program in main.c. This writes to the SB card.

RE: SD Card example design using standalone?

Former Member — Sat, 30 Aug 2014 11:17:21 GMT

originated from chan, then edh4 with bitbanging, here's the (still rough) spi version. The SD card is
connected to the MicroZed PMOD connector.

One caveat though, this was built and tested under the Crossworks toolchain.

https://drive.google.com/file/d/0Bxyv6KTPN_xAQWNCYUthaWhYSms/edit?usp=sharing

RE: SD Card example design using standalone?

Former Member — Thu, 28 Aug 2014 07:49:35 GMT

Hi Erik,

Just one question!? Where to find libraries usbdisk.h, atadrive.h, sdcard.h which are used in diskio.c!? Also the function platform_init() in the main faile is not in any of the header files given!?

Any help would be appreciated.

Jet

RE: SD Card example design using standalone?

Former Member — Mon, 19 May 2014 12:15:35 GMT

Does changing the configuration of the MIO pins connected to the SD card still allow you to boot from the SD card?

-Pat

RE: SD Card example design using standalone?

Former Member — Wed, 14 May 2014 15:42:03 GMT

Hi all,

In a related post, SDIO for Windows 7 (http://www.zedboard.org/comment/3291) Kenny successfully used the SPI protocol to access the SD card on the Zedboard. Unfortunately, the link to his personal implementation seems to be dead.

Therefore I created a sample project which implements the generic FatFs file system on the Zedboard. It is available at https://dl.dropbox.com/s/7i4ioinjkn3a7am/zynq_spi_sdc.zip. The adaptation is largely based on the files and documentation of ChaN's FatFS - Generic FAT File system http://elm-chan.org/fsw/ff/00index_e.html, in particular the AVR sample project.

The configuration uses the Zynq GPIO pins and the Xilinx GPIO driver functions.

Hardware configuration

In the ZYNQ7 processing system the MIO pins 40-45 are connected to the SD card interface.
Since these pins are programmed using the GPIO interface, it is mandatory that the SD0 peripheral in the Zynq Block Design (accessing the same pins) is not selected. On the other hand, the GPIO peripheral needs to be selected.

Programming

The software has been tested using Vivado 2013.2, SDK build 14.6. The sample project main.c writes a file "newfile.txt" onto the SD card and checks the result. The FatFs API-functions are described on the FatFs website http://elm-chan.org/fsw/ff/00index_e.html.

Date and time stamps

Since a bare metal application has no time-of-day function, the timestamp is derived from the user supplied get_fattime function. In the absence of a real-time clock, the user may specify the date and time using the FILDAT and FILTIM strings, e.g.
#define FILDAT "20140514"
#define FILTIM "123500"t

Erik

RE: SD Card example design using standalone?

Former Member — Tue, 12 Nov 2013 10:36:07 GMT

Hi thank you for your step by step instructions.
Could you give me maybe a keyword or an additional hint what to look at in STM32F4xx_SDIO_Example.

I used the FSBL template as a start. After removing most of the code and include files ADMA2 file transfer suddenly stopped working.

After a while I figured that I have to call the InitPcap(void) function in order to fix the problem.

int InitPcap(void)
{
tXDcfg_Config *ConfigPtr;
tint Status = XST_SUCCESS;
tDcfgInstPtr = &DcfgInstance;

t/*
t * Initialize the Device Configuration Interface driver.
t */
tConfigPtr = XDcfg_LookupConfig(DCFG_DEVICE_ID);

tStatus = XDcfg_CfgInitialize(DcfgInstPtr, ConfigPtr,
tttttConfigPtr->BaseAddr);
tif (Status != XST_SUCCESS) {
ttreturn XST_FAILURE;
t}

treturn XST_SUCCESS;
}

Can someone please explain why this is needed? The communication/configuration to and from the card worked fine (responses in accordance with sdc physical spec etc.) but the ADMA2 transfer did not.

Thanks in advance

regards,
Christian

RE: SD Card example design using standalone?

Former Member — Tue, 27 Aug 2013 09:09:09 GMT

I was working on this topic for the last week and I have a solution. Not perfect, but Iu2019m able to write and read from SD card and use the FATFS. Since I'm working on proprietary firmware I can't simply give you the code, but I can help:
The FSBL app from Xilinx implements Chanu2019s FAT FS in readonly mode. This is good start point.
You will have to update ffconf to fill your needs.
Update mmm.c :
u2022tadd definitions for CMD24 (single write) and CMD25 (multiwrite)
u2022tIn the make_command function update CMD24 & CMD25 (both R1 resposes and remember, you are sending DATA)
u2022tIn send_cmd only CMD18 is implemented. Change if/else to switch and add CMD24/25 cases. Take a look on ug585/appendix b.27. Transfer command register is explained in detail.
u2022tThere is a bug in disk_status function. Write_Protect_Switch is 0 when write protected, not 1! Change it. Take a look on ug585/b.27 Present_State register, if you donu2019t understand.
u2022tChange disk_ioctl. STM32F4xx_SDIO_Example was great help.
u2022tCreate disk_write function. Again STM32F4xx_SDIO_Example shows how to do it.
Guys Iu2019m sorry, but I simply canu2019t give you codes. Hope that this helps.

RE: SD Card example design using standalone?

Former Member — Mon, 26 Aug 2013 13:08:53 GMT

I am also working on the SD write, do you have already find the solutions for this? Thanks!

RE: SD Card example design using standalone?

Former Member — Tue, 11 Jun 2013 06:33:07 GMT

Hi all! I'm working on SD driver for eCos and have problems with write operation. I've created this topic on Xilinx forum, but still didn't get any reasonable answer

http://forums.xilinx.com/t5/Embedded-Development-Tools/Zynq-SD-write-operation/m-p/314123

I investigate your version of SD driver, but didn't find write operation too(( I just found return 0. Did you work on SD write op for Zynq ?

RE: SD Card example design using standalone?

Former Member — Thu, 06 Jun 2013 14:46:16 GMT

Hi James. I saw your website, it looks great.
I am using a V707 Virtex 7 board with Xilinx's XPS with an AXI bus, and I'm attempting to access the SD card.
Do you know if your code would work with my project, and if so, how I might go about implementing this?
My partner and I are both new to XPS/FPGA development, and our research professor assigned us this project, but we're pretty much clueless :P.
Chase

RE: SD Card example design using standalone?

Former Member — Mon, 06 May 2013 20:37:18 GMT

Hi Guys,

I mentioned I was working on an SDCard driver.. Well its now working.

See http://github.com/jameswalmsley/bitthunder/
Look under drivers/mmc/sdcard.c and drivers/mmc/host/sdhci.c

Also the Xilinx FSBL provides a rather primitive driver example, but
should help anyone trying to write their own driver.

Hope this helps,

James

RE: SD Card example design using standalone?

Former Member — Wed, 13 Mar 2013 16:00:23 GMT

I'm currently working on SDCard access for my real-time operating system, which is based on FreeRTOS. Unfortunately there seems to be little to no support from Xilinx for doing this.

The other problem is that there really isn't much useful information for handling SD cards using the SDIO protocol. (SPI mode there is a lot of documentation from hobbyists etc, as seen from the provided link).

There are the SDHCI simplified specs, which are useful, but don't seem to provide all the information you need.

Anyway, fortunately there are a few reference drivers you can look at for help.

Obviously there's linux, which provides the most fully featured driver possible, and its pretty complex. As mentioned earlier I'd avoid this unless you have to.

Also the raspberrypi is using an SDHCI controller, similar to that in Zynq.

See:
https://github.com/jameswalmsley/rpi-boot/blob/master/emmc.c

They seem to have full read access to the card, and from that write access should be trivial.

In anycase, I shall have my fully featured driver ready in 2/3 weeks from now (hopefully). So checkout:
https://github.com/jameswalmsley/bitthunder/

The source will be found under: drivers/mmc/host/sdhci.c

Hope this helps someone.

James

RE: SD Card example design using standalone?

Former Member — Mon, 29 Oct 2012 03:55:44 GMT

Thank you both folks. I'll review and get back to the thread with my findings. Thanks again!

Eddie

RE: SD Card example design using standalone?

zedhed — Mon, 22 Oct 2012 15:12:06 GMT

Hi Eddie,

Tim makes a great suggestion above.

I just wanted to add that using only U-Boot may also be an option to look at as well. There are mechanisms built into U-Boot for reading FAT file systems.

Another option to look at, if your code is compact enough, is the FSBL. There are mechanisms in FSBL BSP for reading from the SD card FAT file system. Plus you have the source code available to you for modification.

Going to either of these routes will give you some nice APIs to work with but still keep you at a very low level of complexity when it comes to writing into the PL hardware address space.

Regards,

-Kevin

RE: SD Card example design using standalone?

Former Member — Mon, 22 Oct 2012 15:01:47 GMT

Eddie,

Here is a great thread from the Xilinx forums talking about doing exactly what you would like to do (except on a MicroBlaze processor, however the flow will be very similar).

http://forums.xilinx.com/t5/EDK-and-Platform-Studio/XPS-SPI-Core-and-SD-Card/td-p/173580

Let me know if that helps, and if not we can go through it step by step.