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Diffstat (limited to 'board/st/nhk8815')
| -rw-r--r-- | board/st/nhk8815/README.nhk8815 | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/board/st/nhk8815/README.nhk8815 b/board/st/nhk8815/README.nhk8815 new file mode 100644 index 0000000000..9008e39363 --- /dev/null +++ b/board/st/nhk8815/README.nhk8815 @@ -0,0 +1,32 @@ + +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. |