AR# 69332

2017.1 Zynq UltraScale+ MPSoC: U-boot needs a patch to run eMMC at HS200

Description

Even though the eMMC flash is capable of running at HS200 (200MHz), the 2017.1 u-boot is only capable of detecting speeds of 25MHz or 52MHz, limiting the speed used for the eMMC.

If you are using FSBL and Linux instead, you can use the eMMC at HS200.

This is a limitation of u-boot only.

Solution

The limitation is because the code does not set the bus width before the timing mode switch. 

To fix this issue apply the attached patch to the U-boot.

The patch should be applied to <plnx-proj-root>/project-spec/meta-user/recipes-bsp/u-boot/u-boot_%.bbappend

Note: To apply a patch to recipes, please refer to (UG1144) or http://www.wiki.xilinx.com/PetaLinux+Yocto+Tips

 

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AR# 69332
Date 07/12/2017
Status Active
Type General Article
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