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Diffstat (limited to 'libgloss/or1k/boards/README')
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diff --git a/libgloss/or1k/boards/README b/libgloss/or1k/boards/README deleted file mode 100644 index b6c5abf92..000000000 --- a/libgloss/or1k/boards/README +++ /dev/null @@ -1,65 +0,0 @@ -# Add a new board - -Before adding a new board, you may consider if your board can use another -board definition and simply overwrite the weak symbols. - -If you think it is worth adding a new board, you need to perform the following -steps: - - * Decide for a meaningful board name (refered to as <board> below). It should - be specific enough (not openrisc..), but be rather generic if it may cover - similar boards as well. - - * Create a file <board>.S (assembler) or <board>.c (C). Of course, C is easier - to write and you can implement everything in C, but there are restrictions: - - * There is an early initialization function. It is called before the C - library and even the stack are initialized. A default implementation skips - this step, so everything will compile, but if you really need - initialization that early you are bound to assembly language. - - * You essentially should not use the C library functions as this may lead to - link issues and circular dependencies. - - You can copy board_tmpl.S or board_tmpl.c as starting point for your board. - - * The following symbols must be defined in your board file: - - * _or1k_board_mem_base: Memory base address - - * _or1k_board_mem_size: Memory size - - * _or1k_board_clk_freq: Clock frequency - - * _or1k_board_uart_base: UART base address. Set to 0 if no UART present. - - * _or1k_board_uart_baud: UART baud rate. Only used if UART base is > 0 - - * _or1k_board_uart_IRQ: UART interrupt line. Only used if UART base is > 0 - - You can define a weak attribute for all of the symbols so that they can - be overwritten by the user (more flexibility). - - * The following functions need to be implemented: - - * _or1k_board_init: Is called after C library initialization and UART - initialization. - - * _or1k_board_exit: Is called after the program has exited and the C library - finished all deconstructions etc. - - Similar to the symbols you can define those functions weak. - - * The following functions can be implemented: - - * _or1k_board_init_early: Only in assembly (see above). Is called before - anything is initialized, not even the stack! You can use all registers - in this function. The default implementation in crt0.S skips this step, - which is fine in most cases. If you decide to implement it, you need to - define it with the global attribute to overwrite the default - implementation. It is recommended to do so in assembler board files to - keep the ability to overwrite the default implementation by the user. - -When you are done with your board, add it to libgloss/or1k/Makefile.in to the -BOARDS variable and compile. - |