u-boot/doc/README.davinci.nand_spl

2 A "make boardname" will compile a u-boot.ubl, with UBL Header, which is
3 needed for the RBL to find the "UBL", which actually is a  UBL-compatible
4 header, nand spl code and u-boot code.
7 As the RBL uses another read function as the "standard" u-boot,
8 we need a command, which switches between this two read/write
10 code in a format, which the RBL can read. This is realize
11 (at the moment in board specific code) in the u-boot command
19 To set up mkimage you need a config file for mkimage, example:
26 On the cam_enc_4xx board we have a NAND flash with blocksize = 0x20000 and
27 pagesize = 0x800, so the u-boot.ubl image (which you get with:
34 00000800  14 00 00 ea 14 f0 9f e5  10 f0 9f e5 0c f0 9f e5  |................|
35 00000810  08 f0 9f e5 04 f0 9f e5  00 f0 9f e5 04 f0 1f e5  |................|
42 00003800  14 00 00 ea 14 f0 9f e5  14 f0 9f e5 14 f0 9f e5  |................|
43 00003810  14 f0 9f e5 14 f0 9f e5  14 f0 9f e5 14 f0 9f e5  |................|
49 The spl code starts in the second "page" of the image, with a size
54 After the spl code, there comes the "real" u-boot code
55 @ (6 + 1) * pagesize = 0x3800
57 ------------------------------------------------------------------------
72 ------------------------------------------------------------------------
77 The RBL searches from Block n ( n = 1..24) on page 0 for valid UBL
78 Headers, so you have to burn the UBL header page from the u-boot.ubl
87 !! RBL always starts reading from page 0 !!
93 So we need to copy the spl code to block 5 page 0
98 You need to copy the u-boot image to the block/page
104 #define CONFIG_SYS_NAND_U_BOOT_OFFS	(0xc0000)
106 -> this results in following NAND usage on the cam_enc_4xx board:
115 c0000		u-boot code
121 uboot=/tftpboot/cam_enc_4xx/u-boot.ubl
128 If you do a "run load update" u-boot, spl + ubl header
129 are magically updated ;-)
132 - There seem to be a bug in the RBL code (at least on my HW),
133   In the UBL block, I can set the page to values != 0, so it
136   burn the UBL Header to a page 0 and the spl code to
137   a page 0 ... :-(
138 - If we make the nand read/write functions in the RBL equal to
139   the functions in u-boot (as I have no RBL code, it is only
140   possible in u-boot), we could burn the complete image in