mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-13 14:53:06 +00:00
23 lines
1 KiB
Text
23 lines
1 KiB
Text
|
|
||
|
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.
|
||
|
|
||
|
|
||
|
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.
|