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author | Tom Rini <trini@konsulko.com> | 2021-09-11 15:57:31 +0300 |
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committer | Tom Rini <trini@konsulko.com> | 2021-09-28 00:27:41 +0300 |
commit | c8fff5d2b50f9dee96c84c1c71de7b1c2621b702 (patch) | |
tree | 4a01c3856336331e8876c6150329c63dd7c3c6a9 /board | |
parent | 1d1f98c8eed7bb4792300e655c2cb70136928f74 (diff) | |
download | u-boot-c8fff5d2b50f9dee96c84c1c71de7b1c2621b702.tar.xz |
doc: ti: Convert am335x_evm README to rST
Convert the existing documentation to rST, keeping to just making
formatting changes to start with.
Signed-off-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'board')
-rw-r--r-- | board/ti/am335x/README | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/board/ti/am335x/README b/board/ti/am335x/README deleted file mode 100644 index 19e0eccbac..0000000000 --- a/board/ti/am335x/README +++ /dev/null @@ -1,205 +0,0 @@ -Summary -======= - -This document covers various features of the 'am335x_evm' build, and some of -the related build targets (am335x_evm_uartN, etc). - -Hardware -======== - -The binary produced by this board supports, based on parsing of the EEPROM -documented in TI's reference designs: -- AM335x GP EVM -- AM335x EVM SK -- Beaglebone White -- Beaglebone Black - -Customization -============= - -Given that all of the above boards are reference platforms (and the -Beaglebone platforms are OSHA), it is likely that this platform code and -configuration will be used as the basis of a custom platform. It is -worth noting that aside from things such as NAND or MMC only being -required if a custom platform makes use of these blocks, the following -are required, depending on design: - -- GPIO is only required if DDR3 power is controlled in a way similar to - EVM SK -- SPI is only required for SPI flash, or exposing the SPI bus. - -The following blocks are required: -- I2C, to talk with the PMIC and ensure that we do not run afoul of - errata 1.0.24. - -When removing options as part of customization, -CONFIG_EXTRA_ENV_SETTINGS will need additional care to update for your -needs and to remove no longer relevant options as in some cases we -define additional text blocks (such as for NAND or DFU strings). Also -note that all of the SPL options are grouped together, rather than with -the IP blocks, so both areas will need their choices updated to reflect -the custom design. - -NAND -==== - -The AM335x GP EVM ships with a 256MiB NAND available in most profiles. In -this example to program the NAND we assume that an SD card has been -inserted with the files to write in the first SD slot and that mtdparts -have been configured correctly for the board. All images are first loaded -into memory, then written to NAND. - -Step-1: Building u-boot for NAND boot - Set following CONFIGxx options for NAND device. - CONFIG_SYS_NAND_PAGE_SIZE number of main bytes in NAND page - CONFIG_SYS_NAND_OOBSIZE number of OOB bytes in NAND page - CONFIG_SYS_NAND_BLOCK_SIZE number of bytes in NAND erase-block - CONFIG_SYS_NAND_ECCPOS ECC map for NAND page - CONFIG_NAND_OMAP_ECCSCHEME (refer doc/README.nand) - -Step-2: Flashing NAND via MMC/SD - # select BOOTSEL to MMC/SD boot and boot from MMC/SD card - U-Boot # mmc rescan - # erase flash - U-Boot # nand erase.chip - U-Boot # env default -f -a - U-Boot # saveenv - # flash MLO. Redundant copies of MLO are kept for failsafe - U-Boot # load mmc 0 0x82000000 MLO - U-Boot # nand write 0x82000000 0x00000 0x20000 - U-Boot # nand write 0x82000000 0x20000 0x20000 - U-Boot # nand write 0x82000000 0x40000 0x20000 - U-Boot # nand write 0x82000000 0x60000 0x20000 - # flash u-boot.img - U-Boot # load mmc 0 0x82000000 u-boot.img - U-Boot # nand write 0x82000000 0x80000 0x60000 - # flash kernel image - U-Boot # load mmc 0 0x82000000 uImage - U-Boot # nand write 0x82000000 ${nandsrcaddr} ${nandimgsize} - # flash filesystem image - U-Boot # load mmc 0 0x82000000 filesystem.img - U-Boot # nand write 0x82000000 ${loadaddress} 0x300000 - -Step-3: Set BOOTSEL pin to select NAND boot, and POR the device. - The device should boot from images flashed on NAND device. - -NOR -=== - -The Beaglebone White can be equipped with a "memory cape" that in turn can -have a NOR module plugged into it. In this case it is then possible to -program and boot from NOR. Note that due to how U-Boot is designed we -must build a specific version of U-Boot that knows we have NOR flash. This -build is named 'am335x_evm_nor'. Further, we have a 'am335x_evm_norboot' -build that will assume that the environment is on NOR rather than NAND. In -the following example we assume that and SD card has been populated with -MLO and u-boot.img from a 'am335x_evm_nor' build and also contains the -'u-boot.bin' from a 'am335x_evm_norboot' build. When booting from NOR, a -binary must be written to the start of NOR, with no header or similar -prepended. In the following example we use a size of 512KiB (0x80000) -as that is how much space we set aside before the environment, as per -the config file. - -U-Boot # mmc rescan -U-Boot # load mmc 0 ${loadaddr} u-boot.bin -U-Boot # protect off 08000000 +80000 -U-Boot # erase 08000000 +80000 -U-Boot # cp.b ${loadaddr} 08000000 ${filesize} - -Falcon Mode -=========== - -The default build includes "Falcon Mode" (see doc/README.falcon) via NAND, -eMMC (or raw SD cards) and FAT SD cards. Our default behavior currently is -to read a 'c' on the console while in SPL at any point prior to loading the -OS payload (so as soon as possible) to opt to booting full U-Boot. Also -note that while one can program Falcon Mode "in place" great care needs to -be taken by the user to not 'brick' their setup. As these are all eval -boards with multiple boot methods, recovery should not be an issue in this -worst-case however. - -Falcon Mode: eMMC -================= - -The recommended layout in this case is: - -MMC BLOCKS |--------------------------------| LOCATION IN BYTES -0x0000 - 0x007F : MBR or GPT table : 0x000000 - 0x020000 -0x0080 - 0x00FF : ARGS or FDT file : 0x010000 - 0x020000 -0x0100 - 0x01FF : SPL.backup1 (first copy used) : 0x020000 - 0x040000 -0x0200 - 0x02FF : SPL.backup2 (second copy used) : 0x040000 - 0x060000 -0x0300 - 0x06FF : U-Boot : 0x060000 - 0x0e0000 -0x0700 - 0x08FF : U-Boot Env + Redundant : 0x0e0000 - 0x120000 -0x0900 - 0x28FF : Kernel : 0x120000 - 0x520000 - -Note that when we run 'spl export' it will prepare to boot the kernel. -This includes relocation of the uImage from where we loaded it to the entry -point defined in the header. As these locations overlap by default, it -would leave us with an image that if written to MMC will not boot, so -instead of using the loadaddr variable we use 0x81000000 in the following -example. In this example we are loading from the network, for simplicity, -and assume a valid partition table already exists and 'mmc dev' has already -been run to select the correct device. Also note that if you previously -had a FAT partition (such as on a Beaglebone Black) it is not enough to -write garbage into the area, you must delete it from the partition table -first. - -# Ensure we are able to talk with this mmc device -U-Boot # mmc rescan -U-Boot # tftp 81000000 am335x/MLO -# Write to two of the backup locations ROM uses -U-Boot # mmc write 81000000 100 100 -U-Boot # mmc write 81000000 200 100 -# Write U-Boot to the location set in the config -U-Boot # tftp 81000000 am335x/u-boot.img -U-Boot # mmc write 81000000 300 400 -# Load kernel and device tree into memory, perform export -U-Boot # tftp 81000000 am335x/uImage -U-Boot # run findfdt -U-Boot # tftp ${fdtaddr} am335x/${fdtfile} -U-Boot # run mmcargs -U-Boot # spl export fdt 81000000 - ${fdtaddr} -# Write the updated device tree to MMC -U-Boot # mmc write ${fdtaddr} 80 80 -# Write the uImage to MMC -U-Boot # mmc write 81000000 900 2000 - -Falcon Mode: FAT SD cards -========================= - -In this case the additional file is written to the filesystem. In this -example we assume that the uImage and device tree to be used are already on -the FAT filesystem (only the uImage MUST be for this to function -afterwards) along with a Falcon Mode aware MLO and the FAT partition has -already been created and marked bootable: - -U-Boot # mmc rescan -# Load kernel and device tree into memory, perform export -U-Boot # load mmc 0:1 ${loadaddr} uImage -U-Boot # run findfdt -U-Boot # load mmc 0:1 ${fdtaddr} ${fdtfile} -U-Boot # run mmcargs -U-Boot # spl export fdt ${loadaddr} - ${fdtaddr} - -This will print a number of lines and then end with something like: - Using Device Tree in place at 80f80000, end 80f85928 - Using Device Tree in place at 80f80000, end 80f88928 -So then you: - -U-Boot # fatwrite mmc 0:1 0x80f80000 args 8928 - -Falcon Mode: NAND -================= - -In this case the additional data is written to another partition of the -NAND. In this example we assume that the uImage and device tree to be are -already located on the NAND somewhere (such as filesystem or mtd partition) -along with a Falcon Mode aware MLO written to the correct locations for -booting and mtdparts have been configured correctly for the board: - -U-Boot # nand read ${loadaddr} kernel -U-Boot # load nand rootfs ${fdtaddr} /boot/am335x-evm.dtb -U-Boot # run nandargs -U-Boot # spl export fdt ${loadaddr} - ${fdtaddr} -U-Boot # nand erase.part u-boot-spl-os -U-Boot # nand write ${fdtaddr} u-boot-spl-os |