u-boot/doc/README.nand-boot-ppc440

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2 NAND boot on PPC440 platforms
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5 This document describes the U-Boot NAND boot feature as it
8 The PPC440EP(x)/GR(x) cpu's can boot directly from NAND FLASH,
9 completely without NOR FLASH. This can be done by using the NAND
10 boot feature of the 440 NAND flash controller (NDFC).
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16 Will load first 4k from NAND (SPL) into cache and execute it from there.
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20 Will load special U-Boot version (NUB) from NAND and execute it. This SPL
22 controller and the NAND controller so that the special U-Boot image can be
23 loaded from NAND to SDRAM.
26 c) NUB (NAND U-Boot)
27 --------------------
28 This NAND U-Boot (NUB) is a special U-Boot version which can be started
29 from RAM. Therefore it mustn't (re-)configure the SDRAM controller.
31 On 440EPx the SPL is copied to internal SRAM before the NAND controller
33 the NAND controller.
36 Example: Build and install NAND boot image for Sequoia (440EPx):
38 a) Configure for sequoia with NAND boot support:
45 nand_spl/u-boot-spl.bin
46 Also another image is created spanning a whole NAND block (16kBytes):
47 nand_spl/u-boot-spl-16k.bin
48 The main NAND U-Boot image is generated in the toplevel directory:
49 u-boot.bin
50 A combined image of u-boot-spl-16k.bin and u-boot.bin is also created:
51 u-boot-nand.bin
53 This image should be programmed at offset 0 in the NAND flash:
55 # tftp 100000 /tftpboot/sequoia/u-boot-nand.bin
56 # nand erase 0 60000
57 # nand write 100000 0 60000