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>
This commit is contained in:
Tom Rini 2021-09-11 08:57:31 -04:00
parent 1d1f98c8ee
commit c8fff5d2b5
2 changed files with 87 additions and 64 deletions

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@ -1,3 +1,6 @@
.. SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
.. sectionauthor:: Tom Rini <trini@konsulko.com>
Summary
=======
@ -5,17 +8,17 @@ 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
* 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
@ -24,12 +27,12 @@ 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.
* 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
* 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,
@ -41,7 +44,7 @@ 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
@ -58,6 +61,9 @@ Step-1: Building u-boot for NAND boot
CONFIG_NAND_OMAP_ECCSCHEME (refer doc/README.nand)
Step-2: Flashing NAND via MMC/SD
.. code-block:: text
# select BOOTSEL to MMC/SD boot and boot from MMC/SD card
U-Boot # mmc rescan
# erase flash
@ -84,7 +90,7 @@ 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
@ -100,14 +106,16 @@ 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}
.. code-block:: text
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
@ -119,18 +127,20 @@ 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
.. code-block:: text
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
@ -144,28 +154,30 @@ 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
.. code-block:: text
# 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
@ -173,23 +185,31 @@ 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}
.. code-block:: text
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
.. code-block:: text
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
.. code-block:: text
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
@ -197,9 +217,11 @@ 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
.. code-block:: text
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

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@ -6,4 +6,5 @@ Texas Instruments
.. toctree::
:maxdepth: 2
am335x_evm
j721e_evm