eb18cc19cb
By adding an "eep" memory section, and a NOLOAD step into the linker
scripts, you can now let gcc allocate variables in eeprom for you.
However, as fitting for eeprom, they cannot be initialized, and will not
be loaded at any time. This simply lets you get place variables in the
eeprom space.
Example:
struct whatever __attribute__((section(".eeprom"))) blah;
struct another __attribute__((section(".eeprom"))) wop;
printf("%#x", &blah); // ==> 0x08080000
printf("%#x", &wop); // ==> 0x08080000 + sizeof(blah)
You can read directly out of these variables, but need to use the
eeprom_ routines for writing to them.
112 lines
2.5 KiB
Plaintext
112 lines
2.5 KiB
Plaintext
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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/* Generic linker script for STM32 targets using libopencm3. */
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/* Memory regions must be defined in the ld script which includes this one. */
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/* Enforce emmition of the vector table. */
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EXTERN (vector_table)
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/* Define the entry point of the output file. */
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ENTRY(reset_handler)
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/* Define sections. */
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SECTIONS
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{
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.text : {
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*(.vectors) /* Vector table */
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*(.text*) /* Program code */
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. = ALIGN(4);
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*(.rodata*) /* Read-only data */
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. = ALIGN(4);
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} >rom
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/* C++ Static constructors/destructors, also used for __attribute__
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* ((constructor)) and the likes */
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.preinit_array : {
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. = ALIGN(4);
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__preinit_array_start = .;
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KEEP (*(.preinit_array))
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__preinit_array_end = .;
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} >rom
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.init_array : {
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. = ALIGN(4);
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__init_array_start = .;
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KEEP (*(SORT(.init_array.*)))
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KEEP (*(.init_array))
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__init_array_end = .;
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} >rom
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.fini_array : {
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. = ALIGN(4);
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__fini_array_start = .;
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KEEP (*(.fini_array))
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KEEP (*(SORT(.fini_array.*)))
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__fini_array_end = .;
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} >rom
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/*
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* Another section used by C++ stuff, appears when using newlib with
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* 64bit (long long) printf support
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*/
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.ARM.extab : {
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*(.ARM.extab*)
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} >rom
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.ARM.exidx : {
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__exidx_start = .;
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*(.ARM.exidx*)
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__exidx_end = .;
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} >rom
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. = ALIGN(4);
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_etext = .;
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.data : {
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_data = .;
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*(.data*) /* Read-write initialized data */
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. = ALIGN(4);
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_edata = .;
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} >ram AT >rom
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_data_loadaddr = LOADADDR(.data);
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.bss : {
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*(.bss*) /* Read-write zero initialized data */
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*(COMMON)
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. = ALIGN(4);
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_ebss = .;
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} >ram
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.eeprom (NOLOAD) : {
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. = ALIGN(4);
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*(.eeprom*)
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} >eep
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/*
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* The .eh_frame section appears to be used for C++ exception handling.
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* You may need to fix this if you're using C++.
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*/
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/DISCARD/ : { *(.eh_frame) }
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. = ALIGN(4);
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end = .;
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}
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PROVIDE(_stack = ORIGIN(ram) + LENGTH(ram));
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