| 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 |