Add support for a section(s) ".noinit*" that will be allocated in ram, but not cleared or initialized. This can be used for passing variables between a bootloader and an app for instance, or even just between restarts of your application. Without any assigned usages of the section, there is zero change in ram usage. The align does nothing when the prior section was already aligned.
125 lines
2.8 KiB
Plaintext
125 lines
2.8 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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/*
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* This is a generic linker script for Cortex-M targets using libopencm3.
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*
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* Memory regions MUST be defined in the ld script which includes this one!
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* Example:
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MEMORY
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{
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rom (rx) : ORIGIN = 0x08000000, LENGTH = 256K
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ram (rwx) : ORIGIN = 0x20000000, LENGTH = 16K
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}
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INCLUDE cortex-m-generic.ld
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*/
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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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/* ram, but not cleared on reset, eg boot/app comms */
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.noinit (NOLOAD) : {
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*(.noinit*)
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} >ram
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. = ALIGN(4);
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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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/*
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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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