Argument of eMMC command in i.MX6 boot flow.

[satoshishimoda]

Hi community,

Our customer have a question about i.MX6DQ eMMC boot.

Please Figure 8-10 and 8-11 in IMX6DQRM Rev.3.

They want to know the argument when issue CMD0 in Figure 8-10 and issue CMD1 for voltage validation in Figure 8-11.

In fact, their custom board fails eMMC boot and stops around these commands (CMD0, CMD1).

To confirm corresponding between i.MX6 boot flow and eMMC standard, they want to the argument of these commands.

Best Regards,

Satoshi Shimoda

[igorpadykov]

Hi Satoshi

CMD0,CMD1 are standard emmc command described

in emmc 4.4 specification JESD84-A441  found on www.jedec.org

so one can look at this document. For usdhc usage one can look at attached sdk examples.

Best regards

igor

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[satoshishimoda]

Dear Igor,

> CMD0,CMD1 are standard emmc command described

> in emmc 4.4 specification JESD84-A441  found on www.jedec.org

According to emmc 4.4 specification, the argument of first CMD0 after power-on should be 0xF0F0F0F0 or oxFFFFFFFA.

However, i.MX6 seems to issue CMD0 with 0x00000000 argument.

So our customer want to know what does i.MX6 do by issuing CMD0 with arg=0x00000000.

Best Regards,

Satoshi Shimoda

[igorpadykov]

Hi Satoshi

all publicly available information about ROM is provided in boot

chapter of i.MX6 RM. iROM sources are closed for customers and

additional info about ROM may contain confidential information.

Please elevate this using local fae channel for obtaining special

support.

Best regards

igor

[satoshishimoda]

Dear Igor,

No iROM codes are needed.

Actually, our customer doubt whether i.MX6 eMMC boot compliant with eMMC JEDEC standard.

To prove JEDEC compliant, please let us know the correspondence between JEDEC flow and i.MX6 boot flow.

I believe it is not confidential information if i.MX6 compliant with JEDEC standard.

Best Regards,

Satoshi Shimoda

[igorpadykov]

Hi Satoshi

I checked, rom uses only CMD0 with argument 0xF0F0F0F0.

Best regards

igor