mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-25 14:10:43 +00:00
6ba2da90de
Update m68k documentation to reflect the current ColdFire architecture support status. Signed-off-by: Angelo Dureghello <angelo@sysam.it>
150 lines
4.8 KiB
Text
150 lines
4.8 KiB
Text
|
|
U-Boot for Motorola (or Freescale/NXP) ColdFire processors
|
|
|
|
===============================================================================
|
|
History
|
|
|
|
November 02, 2017 Angelo Dureghello <angelo@sysam.it>
|
|
August 08, 2005 Jens Scharsig <esw@bus-elektronik.de>
|
|
MCF5282 implementation without preloader
|
|
January 12, 2004 <josef.baumgartner@telex.de>
|
|
===============================================================================
|
|
|
|
|
|
This file contains status information for the port of U-Boot to the
|
|
Motorola ColdFire series of CPUs.
|
|
|
|
|
|
1. Overview
|
|
|
|
The ColdFire instruction set is "assembly source" compatible but an evolution
|
|
of the original 68000 instruction set. Some not much used instructions has
|
|
been removed. The instructions are only 16, 32, or 48 bits long, a
|
|
simplification compared to the 68000 series.
|
|
|
|
Bernhard Kuhn ported U-Boot 0.4.0 to the Motorola ColdFire architecture.
|
|
The patches of Bernhard support the MCF5272 and MCF5282. A great disadvantage
|
|
of these patches was that they needed a pre-bootloader to start U-Boot.
|
|
Because of this, a new port was created which no longer needs a first stage
|
|
booter.
|
|
|
|
Thanks mainly to Freescale but also to several other contributors, U-Boot now
|
|
supports nearly the entire range of ColdFire processors and their related
|
|
development boards.
|
|
|
|
|
|
2. Supported CPU families
|
|
|
|
Please "make menuconfig" with ARCH=m68k, or check arch/m68k/cpu to see the
|
|
currently supported processor and families.
|
|
|
|
|
|
3. Supported boards
|
|
|
|
U-Boot supports actually more than 40 ColdFire based boards.
|
|
Board configuration can be done trough include/configs/<boardname>.h but the
|
|
current recommended method is to use the new and more friendly approach as
|
|
the "make menuconfig" way, very similar to the Linux way.
|
|
|
|
To know details as memory map, build targets, default setup, etc, of a
|
|
specific board please check:
|
|
|
|
include/configs/<boardname>.h
|
|
and/or
|
|
configs/<boardname>_defconfig
|
|
|
|
It is possible to build all ColdFire boards in a single command-line command,
|
|
from u-boot root directory, as:
|
|
|
|
./tools/buildman/buildman m68k
|
|
|
|
|
|
3.1. Build U-Boot for a specific board
|
|
|
|
A bash script similar to the one below may be used:
|
|
|
|
#!/bin/bash
|
|
|
|
export CROSS_COMPILE=/opt/toolchains/m68k/gcc-4.9.0-nolibc/bin/m68k-linux-
|
|
|
|
board=M5475DFE
|
|
|
|
make distclean
|
|
make ARCH=m68k ${board}_defconfig
|
|
make ARCH=m68k KBUILD_VERBOSE=1
|
|
|
|
|
|
4. Adopted toolchains
|
|
|
|
Please check:
|
|
https://www.denx.de/wiki/U-Boot/ColdFireNotes
|
|
|
|
|
|
5. ColdFire specific configuration options/settings
|
|
|
|
|
|
5.1. Configuration to use a pre-loader
|
|
|
|
If U-Boot should be loaded to RAM and started by a pre-loader
|
|
CONFIG_MONITOR_IS_IN_RAM must be defined. If it is defined the
|
|
initial vector table and basic processor initialization will not
|
|
be compiled in. The start address of U-Boot must be adjusted in
|
|
the boards config header file (CONFIG_SYS_MONITOR_BASE) and Makefile
|
|
(CONFIG_SYS_TEXT_BASE) to the load address.
|
|
|
|
|
|
5.2 ColdFire CPU specific options/settings
|
|
|
|
To specify a CPU model, some defines shoudl be used, i.e.:
|
|
|
|
CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs
|
|
CONFIG_M5272 -- defined for all Motorola MCF5272 CPUs
|
|
|
|
Other options, generally set inside include/configs/<boardname>.h, they may
|
|
apply to one or more cpu for the ColdFire family:
|
|
|
|
CONFIG_SYS_MBAR -- defines the base address of the MCF5272 configuration
|
|
registers
|
|
CONFIG_SYS_ENET_BD_BASE
|
|
-- defines the base address of the FEC buffer descriptors
|
|
CONFIG_SYS_SCR -- defines the contents of the System Configuration Register
|
|
CONFIG_SYS_SPR -- defines the contents of the System Protection Register
|
|
CONFIG_SYS_MFD -- defines the PLL Multiplication Factor Divider
|
|
(see table 9-4 of MCF user manual)
|
|
CONFIG_SYS_RFD -- defines the PLL Reduce Frequency Devider
|
|
(see table 9-4 of MCF user manual)
|
|
CONFIG_SYS_CSx_BASE
|
|
-- defines the base address of chip select x
|
|
CONFIG_SYS_CSx_SIZE
|
|
-- defines the memory size (address range) of chip select x
|
|
CONFIG_SYS_CSx_WIDTH
|
|
-- defines the bus with of chip select x
|
|
CONFIG_SYS_CSx_MASK
|
|
-- defines the mask for the related chip select x
|
|
CONFIG_SYS_CSx_RO
|
|
-- if set to 0 chip select x is read/write else chip select
|
|
is read only
|
|
CONFIG_SYS_CSx_WS
|
|
-- defines the number of wait states of chip select x
|
|
CONFIG_SYS_CACHE_ICACR
|
|
CONFIG_SYS_CACHE_DCACR
|
|
CONFIG_SYS_CACHE_ACRX
|
|
-- cache-related registers config
|
|
CONFIG_SYS_SDRAM_BASE
|
|
CONFIG_SYS_SDRAM_SIZE
|
|
CONFIG_SYS_SDRAM_BASEX
|
|
CONFIG_SYS_SDRAM_CFG1
|
|
CONFIG_SYS_SDRAM_CFG2
|
|
CONFIG_SYS_SDRAM_CTRL
|
|
CONFIG_SYS_SDRAM_MODE
|
|
CONFIG_SYS_SDRAM_EMOD
|
|
-- SDRAM config for SDRAM controller-specific registers, please
|
|
see arch/m68k/cpu/<specific_cpu>/start.S files to see how
|
|
these options are used.
|
|
CONFIG_MCFUART
|
|
-- defines enabling of ColdFire UART driver
|
|
CONFIG_SYS_UART_PORT
|
|
-- defines the UART port to be used (only a single UART can be
|
|
actually enabled)
|
|
CONFIG_SYS_SBFHDR_SIZE
|
|
-- size of the prepended SBF header, if any
|