I.mx6 board boot from micro-sd card( 8 data line or 4 data line) question?

[laufei]

Hello, Freescale

Our hardware board design is mostly based on the SabreSmart Board( CPU use Dual, DDR3 same, Ethernet same,etc), but the sd card circuit design is different.

We use the micro-sd card which is the same with Sabre-Lite hardware design, and our board is only supported by booting from SD3.

Here is the circuit design difference:

Our Board design:

SabreSmart Board Design:

The SD3 data line, we only use 4 data line. My u-boot baseline is the SabreSmart.

My question is what should I changed from this circuit design changed based on the sabresmart uboot codes?

Thank you for your strong support!

Best Regards

Fe la

[igorpadykov · Accepted solution]

Hi fe

most simple way - just to look at i.MX6 SL EVK design and its Uboot/Linux codes, it uses SD3 in 4 bit configuration

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=IMX6SLEVK&fpsp=1&tab=Design_Tools_Tab

"MCIMX6SLEVK: i.MX 6SoloLite Evaluation Kit schematic"

"L3.0.35_4.1.0_ER_SOURCE_BSP

You can easily generate Uboot codes for i.MX6 SL EVK and Sabre SD and just check differencies.

You should set corect IOMUX settings in Uboot mx6q_sabresd.c.

Please check i.MX_6Dual6Quad_BSP_Porting_Guide.pdf, it is included in Linux Doc bundle

"L3.0.35_4.1.0_LINUX_DOCS "

i.MX6Q: i.MX 6Quad Family of Applications Processors

[justin_jiang]

1. Remove unused pin IOMUX setting in the code.

2. The boot device is selected by boot fuse. You can check the fuse table for SD boot. It can boot in 1-bit or 4-bit mode.

[laufei]

Hello, Jiang Qingrong

Thanks for your very quickly reply!

1. The IOMUX setting whether is in this file  <asm/arch/mx6.h>? Can you help me locate this file?

2.  I checked the datasheet and our boot fuse table, we select the sd3 boot and -1 bits, 2 delay cells. with the same SabreSmart Board configure.

What I am confused is we connected  SD3_DATA0~4, while SDB connect SD3_DATA0~8, If it just use only 1-bits SD3_DATA0, the others SD3_DATA(1~7) are useless?

Best Ragards

Fe la