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136 lines
4.2 KiB
Text
136 lines
4.2 KiB
Text
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U-Boot for Motorola M68K
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Last Update: January 12, 2004
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====================================================================
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This file contains status information for the port of U-Boot to the
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Motorola M68K series of CPUs.
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1. OVERVIEW
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-----------
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Bernhard Kuhn ported U-Boot 0.4.0 to the Motorola Coldfire
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architecture. The patches of Bernhard support the MCF5272 and
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MCF5282. A great disadvantage of these patches was that they needed
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a pre-bootloader to start u-boot. Because of this, a new port was
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created which no longer needs a first stage booter.
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Although this port is intended to cover all M68k processors, only
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the parts for the Motorola Coldfire MCF5272 and MCF5282 are
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implemented at the moment. Additional CPUs and boards will be
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hopefully added soon!
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2. SUPPORTED CPUs
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-----------------
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2.1 Motorola Coldfire MCF5272
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-----------------------------
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CPU specific code is located in: cpu/mcf52x2
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2.1 Motorola Coldfire MCF5282
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-----------------------------
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CPU specific code is located in: cpu/mcf52x2
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At the moment the code isn't fully implemented and still needs a pre-loader!
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The preloader must initialize the processor and then start u-boot. The board
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must be configured for a pre-loader (see 4.1)
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For the preloader, please see
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http://mailman.uclinux.org/pipermail/uclinux-dev/2003-December/023384.html
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U-boot is configured to run at 0x20000 at default. This can be configured by
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change TEXT_BASE in board/m5282evb/config.mk and CFG_MONITOR_BASE in
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include/configs/M5282EVB.h.
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3. SUPPORTED BOARDs
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-------------------
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3.1 Motorola M5272C3 EVB
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------------------------
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Board specific code is located in: board/m5272c3
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To configure the board, type: make M5272C3_config
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U-Boot Memory Map:
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------------------
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0xffe00000 - 0xffe3ffff u-boot
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0xffe04000 - 0xffe05fff environment (embedded in u-boot!)
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0xffe40000 - 0xffffffff free for linux/applications
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3.2 Motorola M5282 EVB
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------------------------
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Board specific code is located in: board/m5282evb
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To configure the board, type: make M5272C3_config
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4. CONFIGURATION OPTIONS/SETTINGS
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----------------------------------
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4.1 Configuration to use a pre-loader
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-------------------------------------
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If u-boot should be loaded to RAM and started by a pre-loader
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CONFIG_MONITOR_IS_IN_RAM must be defined. If it is defined the
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initial vector table and basic processor initialization will not
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be compiled in. The start address of u-boot must be adjusted in
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the boards config header file (CFG_MONITOR_BASE) and Makefile
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(TEXT_BASE) to the load address.
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4.1 MCF5272 specific Options/Settings
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-------------------------------------
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CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs
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CONFIG_M5272 -- defined for all Motorola MCF5272 CPUs
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CONFIG_MONITOR_IS_IN_RAM
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-- defined if u-boot is loaded by a pre-loader
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CFG_MBAR -- defines the base address of the MCF5272 configuration registers
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CFG_INIT_RAM_ADDR
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-- defines the base address of the MCF5272 internal SRAM
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CFG_ENET_BD_BASE
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-- defines the base addres of the FEC buffer descriptors
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CFG_SCR -- defines the contents of the System Configuration Register
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CFG_SPR -- defines the contents of the System Protection Register
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CFG_BRx_PRELIM -- defines the contents of the Chip Select Base Registers
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CFG_ORx_PRELIM -- defines the contents of the Chip Select Option Registers
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CFG_PxDDR -- defines the contents of the Data Direction Registers
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CFG_PxDAT -- defines the contents of the Data Registers
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CFG_PXCNT -- defines the contents of the Port Configuration Registers
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4.2 MCF5282 specific Options/Settings
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-------------------------------------
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CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs
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CONFIG_M5282 -- defined for all Motorola MCF5282 CPUs
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CONFIG_MONITOR_IS_IN_RAM
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-- defined if u-boot is loaded by a pre-loader
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CFG_MBAR -- defines the base address of the MCF5282 internal register space
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CFG_INIT_RAM_ADDR
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-- defines the base address of the MCF5282 internal SRAM
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CFG_INT_FLASH_BASE
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-- defines the base address of the MCF5282 internal Flash memory
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CFG_ENET_BD_BASE
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-- defines the base addres of the FEC buffer descriptors
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5. COMPILER
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-----------
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To create U-Boot the gcc-2.95.3 compiler set (m68k-elf-20030314) from uClinux.org was used.
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You can download it from: http://www.uclinux.org/pub/uClinux/m68k-elf-tools/
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Regards,
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Josef
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<josef.baumgartner@telex.de>
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