micropython/ports/mimxrt/boards/common.ld
robert-hh dfd4324eb1 mimxrt: Add flash storage support with VFS and littlefs filesystem.
This commit adds full support for a filesystem on all boards, with a block
device object mimxrt.Flash() and uos.VfsLfs2 enabled.

Main changes are:
- Refactoring of linker scripts to accomodate reserved area for VFS.  VFS
  will take up most of the available flash. 1M is reserved for code.  9K is
  reserved for flash configuration, interrupts, etc.
- Addition of _boot.py with filesystem init code, called from main.c.
- Definition of the mimxrt module with a Flash class in modmimxrt.[ch].
- Implementation of a flash driver class in mimxrt_flash.c.  All flashing
  related functions are stored in ITCM RAM.
- Addition of the uos module with filesystem functions.
- Implementation of uos.urandom() for the sake of completeness of the uos
  module.

It uses sample code from CircuitPython supplied under MIT license, which
uses the NXP SDK example code.

Done in collaboration with Philipp Ebensberger aka @alphaFred who
contributed the essential part to enable writing to flash while code is
executing, among other things.
2021-06-01 23:42:57 +10:00

263 lines
7.4 KiB
Plaintext

/*
** ###################################################################
** Linker script inspired by NXP linker script for MIMXRT10xx
**
** Copyright for original linker script:
** Copyright 2016 Freescale Semiconductor, Inc.
** Copyright 2016-2018 NXP
** SPDX-License-Identifier: BSD-3-Clause
**
** http: www.nxp.com
** mail: support@nxp.com
**
** Integrated ideas from CircuitPython:
** SPDX-License-Identifier: The MIT License (MIT)
** SPDX-FileCopyrightText: Copyright (c) 2020 Scott Shawcroft (tannewt)
**
** Copyright (c) 2021 Philipp Ebensberger
**
** ###################################################################
*/
/* Entry Point */
ENTRY(Reset_Handler)
HEAP_SIZE = DEFINED(__heap_size__) ? __heap_size__ : 0x0400;
STACK_SIZE = DEFINED(__stack_size__) ? __stack_size__ : 0x0400;
/* Reserved Area
* Users can create a reserved area at the end of the flash memory via
* 'reserved_size' variable. The size of the reserved area should be a multiple
* of the sector size of the flash memory!
*/
reserved_size = DEFINED(reserved_size) ? reserved_size : 0k;
/* Specify the memory areas */
MEMORY
{
m_flash_config (RX) : ORIGIN = flash_config_start, LENGTH = flash_config_size
m_ivt (RX) : ORIGIN = ivt_start, LENGTH = ivt_size
m_interrupts (RX) : ORIGIN = interrupts_start, LENGTH = interrupts_size
m_text (RX) : ORIGIN = text_start, LENGTH = text_size
m_vfs (RX) : ORIGIN = vfs_start, LENGTH = vfs_size
/* Teensy uses the last bit of flash for recovery. */
m_reserved (RX) : ORIGIN = (vfs_start + vfs_size), LENGTH = reserved_size
m_itcm (RX) : ORIGIN = itcm_start, LENGTH = itcm_size
m_dtcm (RW) : ORIGIN = dtcm_start, LENGTH = dtcm_size
m_ocrm (RW) : ORIGIN = ocrm_start, LENGTH = ocrm_size
}
/* Define output sections */
SECTIONS
{
__flash_start = flash_start;
__vfs_start = ORIGIN(m_vfs);
__vfs_end = __vfs_start + LENGTH(m_vfs);
.flash_config :
{
. = ALIGN(4);
__FLASH_BASE = .;
KEEP(* (.boot_hdr.conf)) /* flash config section */
. = ALIGN(4);
} > m_flash_config
ivt_begin = ORIGIN(m_flash_config) + LENGTH(m_flash_config);
.ivt : AT(ivt_begin)
{
. = ALIGN(4);
KEEP(* (.boot_hdr.ivt)) /* ivt section */
KEEP(* (.boot_hdr.boot_data)) /* boot section */
KEEP(* (.boot_hdr.dcd_data)) /* dcd section */
. = ALIGN(4);
} > m_ivt
/* The startup code goes first into internal RAM */
.interrupts :
{
__VECTOR_TABLE = .;
. = ALIGN(4);
KEEP(*(.isr_vector)) /* Startup code */
. = ALIGN(4);
} > m_interrupts
__VECTOR_RAM = __VECTOR_TABLE;
__RAM_VECTOR_TABLE_SIZE_BYTES = 0x0;
/* The program code and other data goes into internal RAM */
.text :
{
. = ALIGN(4);
*(EXCLUDE_FILE(*fsl_flexspi.o) .text*) /* .text* sections (code) */
*(.rodata) /* .rodata sections (constants, strings, etc.) */
*(.rodata*) /* .rodata* sections (constants, strings, etc.) */
*(.glue_7) /* glue arm to thumb code */
*(.glue_7t) /* glue thumb to arm code */
*(.eh_frame)
KEEP (*(.init))
KEEP (*(.fini))
. = ALIGN(4);
} > m_text
.ARM.extab :
{
*(.ARM.extab* .gnu.linkonce.armextab.*)
} > m_text
.ARM :
{
__exidx_start = .;
*(.ARM.exidx*)
__exidx_end = .;
} > m_text
.ctors :
{
__CTOR_LIST__ = .;
/* gcc uses crtbegin.o to find the start of
the constructors, so we make sure it is
first. Because this is a wildcard, it
doesn't matter if the user does not
actually link against crtbegin.o; the
linker won't look for a file to match a
wildcard. The wildcard also means that it
doesn't matter which directory crtbegin.o
is in. */
KEEP (*crtbegin.o(.ctors))
KEEP (*crtbegin?.o(.ctors))
/* We don't want to include the .ctor section from
from the crtend.o file until after the sorted ctors.
The .ctor section from the crtend file contains the
end of ctors marker and it must be last */
KEEP (*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors))
KEEP (*(SORT(.ctors.*)))
KEEP (*(.ctors))
__CTOR_END__ = .;
} > m_text
.dtors :
{
__DTOR_LIST__ = .;
KEEP (*crtbegin.o(.dtors))
KEEP (*crtbegin?.o(.dtors))
KEEP (*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors))
KEEP (*(SORT(.dtors.*)))
KEEP (*(.dtors))
__DTOR_END__ = .;
} > m_text
.preinit_array :
{
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array*))
PROVIDE_HIDDEN (__preinit_array_end = .);
} > m_text
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array*))
PROVIDE_HIDDEN (__init_array_end = .);
} > m_text
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT(.fini_array.*)))
KEEP (*(.fini_array*))
PROVIDE_HIDDEN (__fini_array_end = .);
} > m_text
__etext = .; /* define a global symbol at end of code */
__DATA_ROM = .; /* Symbol is used by startup for data initialization */
.data : AT(__DATA_ROM)
{
. = ALIGN(4);
__DATA_RAM = .;
__data_start__ = .; /* create a global symbol at data start */
*(m_usb_dma_init_data)
*(.data) /* .data sections */
*(.data*) /* .data* sections */
KEEP(*(.jcr*))
. = ALIGN(4);
__data_end__ = .; /* define a global symbol at data end */
} > m_dtcm
__RAM_FUNCTIONS_ROM = __DATA_ROM + (__data_end__ - __data_start__);
.ram_functions : AT(__RAM_FUNCTIONS_ROM)
{
. = ALIGN(4);
__ram_function_start__ = .;
*fsl_flexspi.o(.text*)
*(.ram_functions*)
. = ALIGN(4);
__ram_function_end__ = .;
} > m_itcm
__NDATA_ROM = __DATA_ROM + (__ram_function_end__ - __data_start__);
.ncache.init : AT(__NDATA_ROM)
{
__noncachedata_start__ = .; /* create a global symbol at ncache data start */
*(NonCacheable.init)
. = ALIGN(4);
__noncachedata_init_end__ = .; /* create a global symbol at initialized ncache data end */
} > m_dtcm
. = __noncachedata_init_end__;
.ncache :
{
*(NonCacheable)
. = ALIGN(4);
__noncachedata_end__ = .; /* define a global symbol at ncache data end */
} > m_dtcm
__DATA_END = __NDATA_ROM + (__noncachedata_init_end__ - __noncachedata_start__);
text_end = ORIGIN(m_text) + LENGTH(m_text);
ASSERT(__DATA_END <= text_end, "region m_text overflowed with text and data")
/* Uninitialized data section */
.bss :
{
/* This is used by the startup in order to initialize the .bss section */
. = ALIGN(4);
__START_BSS = .;
__bss_start__ = .;
*(m_usb_dma_noninit_data)
*(.bss)
*(.bss*)
*(COMMON)
. = ALIGN(4);
__bss_end__ = .;
__END_BSS = .;
} > m_dtcm
.heap :
{
. = ALIGN(8);
__end__ = .;
PROVIDE(end = .);
__HeapBase = .;
. += HEAP_SIZE;
__HeapLimit = .;
__heap_limit = .; /* Add for _sbrk */
} > m_dtcm
.stack :
{
. = ALIGN(8);
. += STACK_SIZE;
} > m_dtcm
/* Initializes stack on the end of block */
__StackTop = ORIGIN(m_dtcm) + LENGTH(m_dtcm);
__StackLimit = __StackTop - STACK_SIZE;
PROVIDE(__stack = __StackTop);
.ARM.attributes 0 : { *(.ARM.attributes) }
ASSERT(__StackLimit >= __HeapLimit, "region m_dtcm overflowed with stack and heap")
}