xref: /openbmc/u-boot/board/logicpd/omap3som/README (revision e246b728)
1Summary
2=======
3
4The source for omap3logic.c encompases the OMAP35 and DM3730 SOM-LV and DM3730 Torpedo platforms, but there are device trees custom taylored to each board.
5
6omap3_logic_defconfig = DM37 Torpedo / Torpedo + Wireless
7omap35_logic_defconfig = OMAP35 Torpedo
8omap3_logic_somlv_defconfig = DM37 SOM-LV
9omap35_logic_somlv_defconfig = OMAP35 SOM-LV
10
11The device tree included with each of the defconfig files will also direct the board as to which dtb file to load when loading the kernel, so it is not
12recomended to mix and match the defconfig files.
13
14Falcon Mode: FAT SD cards
15=========================
16
17In this case the additional file is written to the filesystem.  In this
18example we assume that the uImage and device tree to be used are already on
19the FAT filesystem (only the uImage MUST be for this to function
20afterwards) along with a Falcon Mode aware MLO and the FAT partition has
21already been created and marked bootable:
22
23U-Boot # mmc rescan
24# Load kernel and device tree into memory, perform export
25U-Boot # fatload mmc 0 ${loadaddr} uImage
26U-Boot # run loadfdt
27U-Boot # setenv optargs quiet
28U-Boot # run mmcargs
29U-Boot # run common_bootargs
30U-Boot # spl export fdt ${loadaddr} - ${fdtaddr}
31
32This will print a number of lines and then end with something like:
33   Loading Device Tree to 8dec9000, end 8dee0295 ... OK
34
35So then note the starting address and write the args to mmc/sd:
36
37U-Boot # fatwrite mmc 0:1 0x8dec9000 args 0x20000
38
39The size of 0x20000 matches the CMD_SPL_WRITE_SIZE.
40
41Falcon Mode: NAND
42=================
43
44In this case the additional data is written to another partition of the
45NAND.  In this example we assume that the uImage and device tree to be are
46already located on the NAND somewhere (such as filesystem or mtd partition)
47along with a Falcon Mode aware MLO written to the correct locations for
48booting and mtdparts have been configured correctly for the board:
49
50U-Boot # nand read ${loadaddr} kernel
51U-Boot # load nand rootfs ${fdtaddr} /boot/am335x-evm.dtb
52U-Boot # run nandargs
53U-Boot # run common_bootargs
54U-Boot # spl export fdt ${loadaddr} - ${fdtaddr}
55U-Boot # nand erase.part u-boot-spl-os
56U-Boot # nand write ${fdtaddr} u-boot-spl-os
57