From 3c8e76f679158d2a5cb1a16a7da1c4f48066ddfc Mon Sep 17 00:00:00 2001 From: TitanMKD Date: Sun, 10 Jun 2012 11:44:36 +0200 Subject: Added ROM to RAM code copy & exec with example of how to use it (miniblink_rom_to_ram). --- lib/lpc43xx/libopencm3_lpc43xx.ld | 4 ++ lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld | 97 ++++++++++++++++++++++++++++ lib/lpc43xx/vector.c | 19 ++++++ 3 files changed, 120 insertions(+) create mode 100644 lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld (limited to 'lib') diff --git a/lib/lpc43xx/libopencm3_lpc43xx.ld b/lib/lpc43xx/libopencm3_lpc43xx.ld index 5c3221b..47b403b 100644 --- a/lib/lpc43xx/libopencm3_lpc43xx.ld +++ b/lib/lpc43xx/libopencm3_lpc43xx.ld @@ -3,6 +3,7 @@ * * Copyright (C) 2009 Uwe Hermann * Copyright (C) 2012 Michael Ossmann + * Copyright (C) 2012 Benjamin Vernoux * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by @@ -35,6 +36,7 @@ SECTIONS .text : { . = ALIGN(0x400); + _text_ram = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */ *(.vectors) /* Vector table */ *(.text*) /* Program code */ . = ALIGN(4); @@ -50,6 +52,8 @@ SECTIONS __exidx_end = .; _etext = .; + _etext_ram = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */ + _etext_rom = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */ . = ORIGIN(ram); diff --git a/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld b/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld new file mode 100644 index 0000000..f833aaf --- /dev/null +++ b/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld @@ -0,0 +1,97 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2009 Uwe Hermann + * Copyright (C) 2012 Michael Ossmann + * Copyright (C) 2012 Benjamin Vernoux + * + * This library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library. If not, see . + */ + +/* Generic linker script for LPC43XX targets using libopencm3. */ + +/* Memory regions must be defined in the ld script which includes this one. */ + +/* Enforce emmition of the vector table. */ +EXTERN (vector_table) + +/* Define the entry point of the output file. */ +ENTRY(reset_handler) + +/* Define sections. */ +SECTIONS +{ + . = ORIGIN(rom); + + .text : { + . = ALIGN(0x400); + _text_ram = . + ORIGIN(ram); /* Start of Code in RAM */ + + *(.vectors) /* Vector table */ + *(.text*) /* Program code */ + . = ALIGN(4); + *(.rodata*) /* Read-only data */ + . = ALIGN(4); + } >rom + + /* exception index - required due to libgcc.a issuing /0 exceptions */ + __exidx_start = .; + .ARM.exidx : { + *(.ARM.exidx*) + } > rom + __exidx_end = .; + + _etext = .; + _etext_ram = . + ORIGIN(ram); + _etext_rom = . + ORIGIN(rom_flash); + + . = ORIGIN(ram); + + .data : { + _data = .; + *(.data*) /* Read-write initialized data */ + . = ALIGN(4); + _edata = .; + } >ram AT >rom + + .bss : { + *(.bss*) /* Read-write zero initialized data */ + *(COMMON) + . = ALIGN(4); + _ebss = .; + } >ram + + /* exception unwind data - required due to libgcc.a issuing /0 exceptions */ + .ARM.extab : { + *(.ARM.extab*) + } >ram + + /* + * The .eh_frame section appears to be used for C++ exception handling. + * You may need to fix this if you're using C++. + */ + /DISCARD/ : { *(.eh_frame) } + + /* + * Another section used by C++ stuff, appears when using newlib with + * 64bit (long long) printf support - discard it for now. + */ + /DISCARD/ : { *(.ARM.exidx) } + + end = .; + + /* Leave room above stack for IAP to run. */ + __StackTop = ORIGIN(ram) + LENGTH(ram) - 32; + PROVIDE(_stack = __StackTop); +} diff --git a/lib/lpc43xx/vector.c b/lib/lpc43xx/vector.c index 33eee4a..631e54e 100644 --- a/lib/lpc43xx/vector.c +++ b/lib/lpc43xx/vector.c @@ -22,6 +22,7 @@ /* Symbols exported by the linker script(s). */ extern unsigned _etext, _data, _edata, _ebss, _stack; +extern unsigned _etext_ram, _text_ram, _etext_rom; void main(void); void reset_handler(void); @@ -158,11 +159,29 @@ void (*const vector_table[]) (void) = { qei_irqhandler, }; +#define MMIO32(addr) (*(volatile unsigned long*)(addr)) +#define CREG_M4MEMMAP MMIO32( (0x40043000 + 0x100) ) + void reset_handler(void) { volatile unsigned *src, *dest; __asm__("MSR msp, %0" : : "r"(&_stack)); + /* Copy the code from ROM to Real RAM (if enabled) */ + if( (&_etext_ram-&_text_ram) > 0 ) + { + src = &_etext_rom-(&_etext_ram-&_text_ram); + for(dest = &_text_ram; dest < &_etext_ram; ) + { + *dest++ = *src++; + } + + /* Change Shadow memory to Real RAM */ + CREG_M4MEMMAP = (unsigned long)&_text_ram; + + /* Continue Execution in RAM */ + } + for (src = &_etext, dest = &_data; dest < &_edata; src++, dest++) *dest = *src; -- cgit v1.2.3