The Optimus Black
According to the OMAP36xx Technical Reference Manual, section 26.4.4.3 (Booting Device List Setup), the OMAP3630 platform will first choose devices to boot from based on the software booting configuration. If no valid software booting configuration is found, it will read the status of the SYS_BOOT pins to determine the boot device priority order.
According to the OMAP36xx Technical Reference Manual, section 26.4.4.4 (Software Booting Configuration) the software booting configuration is a data structure stored in scratchpad memory, at address 0x48002910. It is not cleared at reset and can be written with a valid structure before reboot, to take effect.
According to the OMAP36xx Technical Reference Manual, table 13-109 (CONTROL_STATUS), the CONTROL_STATUS register provides the values of the SYS_BOOT pins as sampled at reset time. It is located at address: 0x480022f0.
The register value can be read using:
$ devmem 0x480022f0 8 0x25
According to the OMAP36xx Technical Reference Manual, section 26.2.3 (Boot Configuration), the SYS_BOOT[5:0] pins are used to select the boot device priority. SYS_BOOT5 indicated whether peripheral booting is preferred.
According to the Optimus Black (P970) Service Manual:
These documents are the propriety of LG Electronics and Texas Instruments and are not hosted by the Replicant project.
However, some excerpts from these documents are provided, for the purpose of providing technical evidence of the facts that are mentioned in this page. We believe that this particular use of the copyrighted work is fair use.