|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
|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.