1 2U-Boot for Motorola M68K 3 4Last Update: January 12, 2004 5==================================================================== 6 7This file contains status information for the port of U-Boot to the 8Motorola M68K series of CPUs. 9 101. OVERVIEW 11----------- 12Bernhard Kuhn ported U-Boot 0.4.0 to the Motorola Coldfire 13architecture. The patches of Bernhard support the MCF5272 and 14MCF5282. A great disadvantage of these patches was that they needed 15a pre-bootloader to start u-boot. Because of this, a new port was 16created which no longer needs a first stage booter. 17 18Although this port is intended to cover all M68k processors, only 19the parts for the Motorola Coldfire MCF5272 and MCF5282 are 20implemented at the moment. Additional CPUs and boards will be 21hopefully added soon! 22 23 242. SUPPORTED CPUs 25----------------- 26 272.1 Motorola Coldfire MCF5272 28----------------------------- 29CPU specific code is located in: cpu/mcf52x2 30 31 322.1 Motorola Coldfire MCF5282 33----------------------------- 34CPU specific code is located in: cpu/mcf52x2 35 36At the moment the code isn't fully implemented and still needs a pre-loader! 37The preloader must initialize the processor and then start u-boot. The board 38must be configured for a pre-loader (see 4.1) 39 40For the preloader, please see 41http://mailman.uclinux.org/pipermail/uclinux-dev/2003-December/023384.html 42 43U-boot is configured to run at 0x20000 at default. This can be configured by 44change TEXT_BASE in board/m5282evb/config.mk and CFG_MONITOR_BASE in 45include/configs/M5282EVB.h. 46 47 483. SUPPORTED BOARDs 49------------------- 50 513.1 Motorola M5272C3 EVB 52------------------------ 53Board specific code is located in: board/m5272c3 54 55To configure the board, type: make M5272C3_config 56 57U-Boot Memory Map: 58------------------ 590xffe00000 - 0xffe3ffff u-boot 600xffe04000 - 0xffe05fff environment (embedded in u-boot!) 610xffe40000 - 0xffffffff free for linux/applications 62 63 643.2 Motorola M5282 EVB 65------------------------ 66Board specific code is located in: board/m5282evb 67 68To configure the board, type: make M5272C3_config 69 70 714. CONFIGURATION OPTIONS/SETTINGS 72---------------------------------- 73 744.1 Configuration to use a pre-loader 75------------------------------------- 76If u-boot should be loaded to RAM and started by a pre-loader 77CONFIG_MONITOR_IS_IN_RAM must be defined. If it is defined the 78initial vector table and basic processor initialization will not 79be compiled in. The start address of u-boot must be adjusted in 80the boards config header file (CFG_MONITOR_BASE) and Makefile 81(TEXT_BASE) to the load address. 82 83 844.1 MCF5272 specific Options/Settings 85------------------------------------- 86 87CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs 88CONFIG_M5272 -- defined for all Motorola MCF5272 CPUs 89 90CONFIG_MONITOR_IS_IN_RAM 91 -- defined if u-boot is loaded by a pre-loader 92 93CFG_MBAR -- defines the base address of the MCF5272 configuration registers 94CFG_INIT_RAM_ADDR 95 -- defines the base address of the MCF5272 internal SRAM 96CFG_ENET_BD_BASE 97 -- defines the base addres of the FEC buffer descriptors 98 99CFG_SCR -- defines the contents of the System Configuration Register 100CFG_SPR -- defines the contents of the System Protection Register 101CFG_BRx_PRELIM -- defines the contents of the Chip Select Base Registers 102CFG_ORx_PRELIM -- defines the contents of the Chip Select Option Registers 103 104CFG_PxDDR -- defines the contents of the Data Direction Registers 105CFG_PxDAT -- defines the contents of the Data Registers 106CFG_PXCNT -- defines the contents of the Port Configuration Registers 107 108 1094.2 MCF5282 specific Options/Settings 110------------------------------------- 111 112CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs 113CONFIG_M5282 -- defined for all Motorola MCF5282 CPUs 114 115CONFIG_MONITOR_IS_IN_RAM 116 -- defined if u-boot is loaded by a pre-loader 117 118CFG_MBAR -- defines the base address of the MCF5282 internal register space 119CFG_INIT_RAM_ADDR 120 -- defines the base address of the MCF5282 internal SRAM 121CFG_INT_FLASH_BASE 122 -- defines the base address of the MCF5282 internal Flash memory 123CFG_ENET_BD_BASE 124 -- defines the base addres of the FEC buffer descriptors 125 126 1275. COMPILER 128----------- 129To create U-Boot the gcc-2.95.3 compiler set (m68k-elf-20030314) from uClinux.org was used. 130You can download it from: http://www.uclinux.org/pub/uClinux/m68k-elf-tools/ 131 132 133Regards, 134 135Josef 136<josef.baumgartner@telex.de> 137