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jeremybenn |
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FREERTOS COLDFIRE MCF523x PORT with lwIP
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REQUIREMENTS
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============
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The FreeRTOS port is designed for the MCF523x processor where the hardware
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dependent part consists of the CPU and the peripherals used in this port.
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This includes a programmable timer (PIT) for the preemptive scheduler
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and a UART for the demo application. The Coldfire specific part includes
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the number and type of processor registers, the stack frame layout and
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the usage of a software interrupt (trap) for the yield call.
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The development environment used is based on the GNU C Compiler for
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a m68k-elf target as well as the insight debugger with some patches for
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the BDM interface[1]. GDB startup and linker scripts are supplied with
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the demo for the M5235BCC evaluation kit from Freescale.
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[1] ... BDM tools: http://sourceforge.net/projects/bdm/
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USAGE
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=====
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A makefile is supplied with the demo application and a binary can be
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produced by calling 'make all'. A special target 'debug' is provided
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which executes the insight debugger. At the insight debugger prompt
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one should select the appropriate target interface (either BDM/Direct
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or BDM/TCP) and should download the application to the development
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board. It is important that the GDB script setup-and-load is executed
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prior to downloading to initialize the SDRAM. After downloading one
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should call the GDB function 'execute' and the PC is set to the start
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of the executable. Execution can be started by typing 'continue' at
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the Insight console interface.
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After this startup phase the insight debugger should work as usual, i.e.
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no grayed out buttons, ...
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COMMON PROBLEMS
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===============
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Most of the problems have their origin in the startup scripts. The
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following list should serve as a checklist where each point must be
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satisfied for the port to work.
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- The FreeRTOS port only works correctly in the supervisor mode. There-
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fore the Coldfire CPU must run in the supervisor mode.
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- portVECTOR_TABLE does not point to the currently active vector table.
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Please also note that the vector table must be in RAM such that the
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FreeRTOS port can install a traphandler for the portYIELD() call.
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$Id: README.txt 2 2011-07-17 20:13:17Z filepang@gmail.com $
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MCF5235 + lwIP port - Copyright (c) 2006 Christian Walter.
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