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 40U-boot is configured to run at 0x20000 at default. This can be configured by 41change TEXT_BASE in board/m5282evb/config.mk and CFG_MONITOR_BASE in 42include/configs/M5282EVB.h. 43 44 453. SUPPORTED BOARDs 46------------------- 47 483.1 Motorola M5272C3 EVB 49------------------------ 50Board specific code is located in: board/m5272c3 51 52To configure the board, type: make M5272C3_config 53 54U-Boot Memory Map: 55------------------ 560xffe00000 - 0xffe3ffff u-boot 570xffe04000 - 0xffe05fff environment (embedded in u-boot!) 580xffe40000 - 0xffffffff free for linux/applications 59 60 613.2 Motorola M5282 EVB 62------------------------ 63Board specific code is located in: board/m5282evb 64 65To configure the board, type: make M5272C3_config 66 67 684. CONFIGURATION OPTIONS/SETTINGS 69---------------------------------- 70 714.1 Configuration to use a pre-loader 72------------------------------------- 73If u-boot should be loaded to RAM and started by a pre-loader 74CONFIG_MONITOR_IS_IN_RAM must be defined. If it is defined the 75initial vector table and basic processor initialization will not 76be compiled in. The start address of u-boot must be adjusted in 77the boards config header file (CFG_MONITOR_BASE) and Makefile 78(TEXT_BASE) to the load address. 79 80 814.1 MCF5272 specific Options/Settings 82------------------------------------- 83 84CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs 85CONFIG_M5272 -- defined for all Motorola MCF5272 CPUs 86 87CONFIG_MONITOR_IS_IN_RAM 88 -- defined if u-boot is loaded by a pre-loader 89 90CFG_MBAR -- defines the base address of the MCF5272 configuration registers 91CFG_INIT_RAM_ADDR 92 -- defines the base address of the MCF5272 internal SRAM 93CFG_ENET_BD_BASE 94 -- defines the base addres of the FEC buffer descriptors 95 96CFG_SCR -- defines the contents of the System Configuration Register 97CFG_SPR -- defines the contents of the System Protection Register 98CFG_BRx_PRELIM -- defines the contents of the Chip Select Base Registers 99CFG_ORx_PRELIM -- defines the contents of the Chip Select Option Registers 100 101CFG_PxDDR -- defines the contents of the Data Direction Registers 102CFG_PxDAT -- defines the contents of the Data Registers 103CFG_PXCNT -- defines the contents of the Port Configuration Registers 104 105 1064.2 MCF5282 specific Options/Settings 107------------------------------------- 108 109CONFIG_MCF52x2 -- defined for all MCF52x2 CPUs 110CONFIG_M5282 -- defined for all Motorola MCF5282 CPUs 111 112CONFIG_MONITOR_IS_IN_RAM 113 -- defined if u-boot is loaded by a pre-loader 114 115CFG_MBAR -- defines the base address of the MCF5282 internal register space 116CFG_INIT_RAM_ADDR 117 -- defines the base address of the MCF5282 internal SRAM 118CFG_INT_FLASH_BASE 119 -- defines the base address of the MCF5282 internal Flash memory 120CFG_ENET_BD_BASE 121 -- defines the base addres of the FEC buffer descriptors 122 123 1245. COMPILER 125----------- 126To create U-Boot the gcc-2.95.3 compiler set (m68k-elf-20030314) from uClinux.org was used. 127You can download it from: http://www.uclinux.org/pub/uClinux/m68k-elf-tools/ 128 129 130Regards, 131 132Josef 133<josef.baumgartner@telex.de> 134