document where u-boot is retrieved from by SoM
This is similar to #2 but a summary of how u-boot is retrieved for all SoMs. The second and third column show whether u-boot can (and if yes, when) it will be retrieved from sd and emmc, respectively. The fourth column shows whether u-boot is flashed to a dedicated boot0 partition (when flashing to emmc) or directly to the main eMMC block device.
| SoM | from sd | from emmc | boot0 |
|---|---|---|---|
| i.MX8MQ | DIP switch ON | DIP switch OFF | yes |
| i.MX8M+ | never | yes | yes |
| LS1028A | yes | never | n.a. |
| A311D | if emmc zeroed | yes | yes |
| RK3588 | if emmc zeroed | yes | no |
While we are at it, a table showing whether eMMC or SD-Card is mmcblk0 or mmcblk1 or mmcblk2.
| SoM | eMMC | SD-Card |
|---|---|---|
| i.MX8MQ | mmcblk0 | mmcblk1 |
| i.MX8M+ | mmcblk2 | mmcblk0 |
| LS1028A | mmcblk1 | mmcblk0 |
| A311D | mmcblk1 | mmcblk0 |
| RK3588 | mmcblk0 | mmcblk1 |