AM625: Booting from SDCARD2 using MMC2

naveenkumar Muthusamy

Prodigy 140 points

Part Number: AM625

Tool/software:

Hi,

we are trying to boot from SD card using the MMC2 port.we have done the changes in the device tree as below,

};

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    /* On-module Wi-Fi on WB SKUs, module-specific SDIO otherwise */
    pinctrl_sdhci2: main-mmc2-pins-default {
        pinctrl-single,pins = <
            AM62X_IOPAD(0x120, PIN_INPUT, 0) /* (C24) MMC2_CMD   */ /* WiFi_SDIO_CMD   */
            AM62X_IOPAD(0x118, PIN_INPUT, 0) /* (D25) MMC2_CLK   */ /* WiFi_SDIO_CLK   */
            AM62X_IOPAD(0x114, PIN_INPUT, 0) /* (B24) MMC2_DAT0  */ /* WiFi_SDIO_DATA0 */
            AM62X_IOPAD(0x110, PIN_INPUT, 0) /* (C25) MMC2_DAT1  */ /* WiFi_SDIO_DATA1 */
            AM62X_IOPAD(0x10c, PIN_INPUT, 0) /* (E23) MMC2_DAT2  */ /* WiFi_SDIO_DATA2 */
            AM62X_IOPAD(0x108, PIN_INPUT, 0) /* (D24) MMC2_DAT3  */ /* WiFi_SDIO_DATA3 */
            AM62X_IOPAD(0x11c, PIN_INPUT, 0) /* (#N/A) MMC2_CLKB */
        >;
    };
    
        /* Verdin SD_2_CD# as GPIO */
    pinctrl_sd2_cd_gpio: main-gpio0-71-pins-default {
        pinctrl-single,pins = <
            AM62X_IOPAD(0x0124, PIN_INPUT_PULLUP, 7) /* (A23) MMC2_SDCD.GPIO0_71 */ /* SODIMM 157 */
        >;
    };
    
    &sdhci2 {
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

	/* On-module Wi-Fi on WB SKUs, module-specific SDIO otherwise */
	pinctrl_sdhci2: main-mmc2-pins-default {
		pinctrl-single,pins = <
			AM62X_IOPAD(0x120, PIN_INPUT, 0) /* (C24) MMC2_CMD   */ /* WiFi_SDIO_CMD   */
			AM62X_IOPAD(0x118, PIN_INPUT, 0) /* (D25) MMC2_CLK   */ /* WiFi_SDIO_CLK   */
			AM62X_IOPAD(0x114, PIN_INPUT, 0) /* (B24) MMC2_DAT0  */ /* WiFi_SDIO_DATA0 */
			AM62X_IOPAD(0x110, PIN_INPUT, 0) /* (C25) MMC2_DAT1  */ /* WiFi_SDIO_DATA1 */
			AM62X_IOPAD(0x10c, PIN_INPUT, 0) /* (E23) MMC2_DAT2  */ /* WiFi_SDIO_DATA2 */
			AM62X_IOPAD(0x108, PIN_INPUT, 0) /* (D24) MMC2_DAT3  */ /* WiFi_SDIO_DATA3 */
			AM62X_IOPAD(0x11c, PIN_INPUT, 0) /* (#N/A) MMC2_CLKB */
		>;
	};
	
	    /* Verdin SD_2_CD# as GPIO */
    pinctrl_sd2_cd_gpio: main-gpio0-71-pins-default {
        pinctrl-single,pins = <
            AM62X_IOPAD(0x0124, PIN_INPUT_PULLUP, 7) /* (A23) MMC2_SDCD.GPIO0_71 */ /* SODIMM 157 */
        >;
    };
    
    &sdhci2 {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_sdhci2>, <&pinctrl_sd2_cd_gpio>;
	cd-gpios = <&main_gpio1 71 GPIO_ACTIVE_LOW>;
	disable-wp;
	ti,fails-without-test-cd;
	ti,driver-strength-ohm = <33>;
	status = "okay";
};

we bitbake .wic image and write it into external Sd card using Sudo DD commad.

the issue is that when i try to boot from Sd card using mmc2.

in u-boot when i use the commad mmc dev 2, it returns an error stating No MMC 2 device found.

is there anything wrong in the above config or suggest me a way to boot from MMC2!

Thanks in advance.

7 months ago

0 Prashant Shivhare 6 months ago

TI__Guru 57121 points

Hello,

The SD card connector is interfaced to MMC1 port on TI AM62x EVM. Have you connected the connector to MMC2 port on your board?

Can you also clarify if you have made the changes in the U-Boot or Kernel device trees? If you could share the modifications in git diff format that would be helpful.

Thanks!

0 naveenkumar Muthusamy 6 months ago in reply to Prashant Shivhare

Prodigy 140 points

Hi, we have connected the SD card to MMC2 port , and the above are changes added to the kernel device tree file and one more change is that currenlty we have disabled the sdhci1m usb1 and usb2 in kernel device tree.

there is no change made in u-boot

0 Prashant Shivhare 6 months ago in reply to naveenkumar Muthusamy

TI__Guru 57121 points

Hi, could you please help clarify the following queries?

The ROM supports SD card boot only from the MMC1 port. May I know the reason for interfacing the SD card with MMC2 port? How do you plan to boot the `tiboot3.bin`?
How are you booting to A53 U-Boot (u-boot.img)?

Also, since you haven't changed the U-Boot device trees, the U-Boot expectedly will not identify any MMC2 device.

0 naveenkumar Muthusamy 6 months ago in reply to Prashant Shivhare

Prodigy 140 points

we have designed a custom board in which the SD card boot is from MMC2, is it possible to boot from MMC2.

if i update the u-boot device tree to add MMC2, will it boot from MMC2

+1 Prashant Shivhare 6 months ago in reply to naveenkumar Muthusamy

TI__Guru 57121 points

naveenkumar Muthusamy said:
we have designed a custom board in which the SD card boot is from MMC2, is it possible to boot from MMC2.

The ROM cannot boot the `tiboot3.bin` from the SD card interfaced to MMC2 port.

0 naveenkumar Muthusamy 6 months ago in reply to Prashant Shivhare

Prodigy 140 points

Hi,

Thanks for the reply.

As you said we cannot boot sd card from the mmc2. We have tried multiple options. But I believe we can use that port to connect a sd card which should detect as normal sd card under lsblk.

Will this be possible?

0 Prashant Shivhare 6 months ago in reply to naveenkumar Muthusamy

TI__Guru 57121 points

Hello,

naveenkumar Muthusamy said:
Will this be possible?

Yes, but on paper. The TRM does mention the MMC1/2 ports are designed to work with both SD or SDIO devices.

However, we have not tested the SD card interfaced to MMC2. There are also no reported instances of any other customer testing the same.

Regards,

Prashant

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AM625: Booting from SDCARD2 using MMC2