| |
| The Nomadik 8815 CPU has a "secure" boot mode where no external access |
| (not even JTAG) is allowed. The "remap" bits in the evaluation board |
| are configured in order to boot from the internal ROM memory (in |
| secure mode). |
| |
| The boot process as defined by the manufacturer executes external code |
| (loaded from NAND or OneNAND) that that disables such "security" in |
| order to run u-boot and later the kernel without constraints. Such |
| code is a proprietary initial boot loader, called "X-Loader" (in case |
| anyone wonders, it has no relations with other loaders with the same |
| name and there is no GPL code inside the ST X-Loader). |
| |
| SDRAM configuration, PLL setup and initial loading from NAND is |
| implemented in the X-Loader, so U-Boot is already running in SDRAM |
| when control is handed over to it. |
| |
| The Makefile offers two different configurations to be used if you |
| boot from Nand or OneNand. |
| |
| make nhk8815_config |
| make nhk8815_onenand_config |
| |
| Both support OneNand and Nand. Since U-Boot, running in RAM, can't know |
| where it was loaded from, the configurations differ in where the filesystem |
| is looked for by default. |
| |
| |
| On www.st.com/nomadik and on www.stnwireless.com there are documents, |
| summary data and white papers on Nomadik. The full datasheet for |
| STn8815 is not currently available on line but under specific request |
| to the local ST sales offices. |
