xref: /openbmc/u-boot/doc/README.m68k (revision 3cbeb0f0)
1
2U-Boot for Motorola M68K
3
4====================================================================
5History
6
7August 08,2005;		Jens Scharsig <esw@bus-elektronik.de>
8			MCF5282 implementation without preloader
9January 12, 2004;	<josef.baumgartner@telex.de>
10====================================================================
11
12This file contains status information for the port of U-Boot to the
13Motorola M68K series of CPUs.
14
151. OVERVIEW
16-----------
17Bernhard Kuhn ported U-Boot 0.4.0 to the Motorola Coldfire
18architecture. The patches of Bernhard support the MCF5272 and
19MCF5282. A great disadvantage of these patches was that they needed
20a pre-bootloader to start u-boot. Because of this, a new port was
21created which no longer needs a first stage booter.
22
23Although this port is intended to cover all M68k processors, only
24the parts for the Motorola Coldfire MCF5272 and MCF5282 are
25implemented at the moment. Additional CPUs and boards will be
26hopefully added soon!
27
28
292. SUPPORTED CPUs
30-----------------
31
322.1 Motorola Coldfire MCF5272
33-----------------------------
34CPU specific code is located in: arch/m68k/cpu/mcf52x2
35
36
372.1 Motorola Coldfire MCF5282
38-----------------------------
39CPU specific code is located in: arch/m68k/cpu/mcf52x2
40
41The MCF5282 Port no longer needs a preloader and can place in external or
42internal FLASH.
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
67At the moment the code isn't fully implemented and still needs a pre-loader!
68The preloader must initialize the processor and then start u-boot. The board
69must be configured for a pre-loader (see 4.1)
70
71For the preloader, please see
72http://mailman.uclinux.org/pipermail/uclinux-dev/2003-December/023384.html
73
74U-boot is configured to run at 0x20000 at default. This can be configured by
75change CONFIG_SYS_TEXT_BASE in board/m5282evb/config.mk and CONFIG_SYS_MONITOR_BASE in
76include/configs/M5282EVB.h.
77
783.2 BuS EB+MCF-EV123
79---------------------
80
81Board specific code is located in: board/bus/EB+MCF-EV123
82
83To configure the board, type:
84
85make EB+MCF-EV123_config		for external FLASH
86make EB+MCF-EV123_internal_config	for internal FLASH
87
88
894. CONFIGURATION OPTIONS/SETTINGS
90----------------------------------
91
924.1 Configuration to use a pre-loader
93-------------------------------------
94If u-boot should be loaded to RAM and started by a pre-loader
95CONFIG_MONITOR_IS_IN_RAM must be defined. If it is defined the
96initial vector table and basic processor initialization will not
97be compiled in. The start address of u-boot must be adjusted in
98the boards config header file (CONFIG_SYS_MONITOR_BASE) and Makefile
99(CONFIG_SYS_TEXT_BASE) to the load address.
100
1014.1 MCF5272 specific Options/Settings
102-------------------------------------
103
104CONFIG_MCF52x2	-- defined for all MCF52x2 CPUs
105CONFIG_M5272	-- defined for all Motorola MCF5272 CPUs
106
107CONFIG_MONITOR_IS_IN_RAM
108		-- defined if u-boot is loaded by a pre-loader
109
110CONFIG_SYS_MBAR	-- defines the base address of the MCF5272 configuration registers
111CONFIG_SYS_INIT_RAM_ADDR
112		-- defines the base address of the MCF5272 internal SRAM
113CONFIG_SYS_ENET_BD_BASE
114		-- defines the base address of the FEC buffer descriptors
115
116CONFIG_SYS_SCR		-- defines the contents of the System Configuration Register
117CONFIG_SYS_SPR		-- defines the contents of the System Protection Register
118CONFIG_SYS_BRx_PRELIM	-- defines the contents of the Chip Select Base Registers
119CONFIG_SYS_ORx_PRELIM	-- defines the contents of the Chip Select Option Registers
120
121CONFIG_SYS_PxDDR	-- defines the contents of the Data Direction Registers
122CONFIG_SYS_PxDAT	-- defines the contents of the Data Registers
123CONFIG_SYS_PXCNT	-- defines the contents of the Port Configuration Registers
124
125
1264.2 MCF5282 specific Options/Settings
127-------------------------------------
128
129CONFIG_MCF52x2	-- defined for all MCF52x2 CPUs
130CONFIG_M5282	-- defined for all Motorola MCF5282 CPUs
131
132CONFIG_MONITOR_IS_IN_RAM
133		-- defined if u-boot is loaded by a pre-loader
134
135CONFIG_SYS_MBAR	-- defines the base address of the MCF5282 internal register space
136CONFIG_SYS_INIT_RAM_ADDR
137		-- defines the base address of the MCF5282 internal SRAM
138CONFIG_SYS_INT_FLASH_BASE
139		-- defines the base address of the MCF5282 internal Flash memory
140CONFIG_SYS_ENET_BD_BASE
141		-- defines the base address of the FEC buffer descriptors
142
143CONFIG_SYS_MFD
144		-- defines the PLL Multiplication Factor Devider
145		   (see table 9-4 of MCF user manual)
146CONFIG_SYS_RFD		-- defines the PLL Reduce Frecuency Devider
147		   (see table 9-4 of MCF user manual)
148
149CONFIG_SYS_CSx_BASE	-- defines the base address of chip select x
150CONFIG_SYS_CSx_SIZE	-- defines the memory size (address range) of chip select x
151CONFIG_SYS_CSx_WIDTH	-- defines the bus with of chip select x
152CONFIG_SYS_CSx_RO	-- if set to 0 chip select x is read/wirte
153			else chipselct is read only
154CONFIG_SYS_CSx_WS	-- defines the number of wait states  of chip select x
155
156CONFIG_SYS_PxDDR	-- defines the contents of the Data Direction Registers
157CONFIG_SYS_PxDAT	-- defines the contents of the Data Registers
158CONFIG_SYS_PXCNT	-- defines the contents of the Port Configuration Registers
159
160CONFIG_SYS_PxPAR	-- defines the function of ports
161
162
1635. COMPILER
164-----------
165To create U-Boot the gcc-2.95.3 compiler set (m68k-elf-20030314) from uClinux.org was used.
166You can download it from: http://www.uclinux.org/pub/uClinux/m68k-elf-tools/
167