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- 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.
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