Allwinner H3 boot From 4 bit eMMC

[Mahmoud Tolba]

Hi there,

I'm working on a custom design for Allwinner H3 and I used SD card connected to SDC0 as the primary boot device, Now I want to replace the SD card with an eMMC chip (KLM8G1GESD-B03P from Samsung) as the primary boot device.

Now I have two options:

1. Connecting the eMMC chip on SDC0 but in this case, I have to use the 4-bit mode, right? I'm not sure if the eMMC can operate on 4-bit mode. So it would be nice if you can confirm that.

2. Connecting the eMMC chip on SDC2, but in this case I will use it in 8-bit mode. In this scenario, what would I lose in terms of functionality if I left SDC0 unconnected and connected my boot storage to SDC2? (FYI, I'm not using NAND or SPI storage and I use SDC1 for the WiFi Module.)

I'm using sunxi-uboot and sunxi-kernel (next branches)

Waiting to hear from you.

Best regards,