ARM Initialization Question

Mon Sep 15 16:44:58 UTC 2008

hi
i'm doing a bsp for SAM7 which is an arm with code in ROM, so i can get the rom version of this linker file and  how to use the function you are talking about to detect work area so that we can standarise it.

Thanks> Date: Mon, 15 Sep 2008 14:02:07 +0200> From: sebastian.huber at embedded-brains.de> To: joel.sherrill at oarcorp.com> Subject: Re: ARM Initialization Question> CC: rtems-users at rtems.com> > Joel Sherrill wrote:> > Sebastian Huber wrote:> >> Hi,> >> I am quite new to the ARM architecture and try to develop a BSP for the> >> LPC2478. I have a question to the initialization code (random start.S):> >>> >> > > Just firing a warning shot .. I am starting to refactor out> > more common code from the BSPs. Please try to help out> > by moving with me to the better place. :)> > > > + You know about bsp_get_work_area. I am starting to> > put it in "startup/bspgetworkarea.c" not bspstart.c> > and reworking all BSPs to have one.> [...]> > I try to provide two general purpose linker command files (one for RAM > only and one for code in ROM). With such a linker command file it is > possible to use a generic version of bsp_get_work_area(). Reducing the > amount of linker command files increases the maintainablity and makes > development of new BSPs easier. Here is my proposal for the ARM:> > /**> * @file> *> * @brief Linker command file for configuration with internal and > external RAM.> */> > /*> * Copyright (c) 2008> * Embedded Brains GmbH> * Obere Lagerstr. 30> * D-82178 Puchheim> * Germany> * rtems at embedded-brains.de> *> * The license and distribution terms for this file may be found in the > file> * LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.> */> > OUTPUT_FORMAT ("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")> > OUTPUT_ARCH (arm)> > ENTRY (start)> > /*> * BSP: Symbols that may be defined externally. The minimum alignment> * requirement for regions is bsp_section_align.> */> bsp_ram_int_size = DEFINED (bsp_ram_int_size) ? bsp_ram_int_size : > LENGTH (RAM_INT);> > bsp_ram_ext_size = DEFINED (bsp_ram_ext_size) ? bsp_ram_ext_size : > LENGTH (RAM_EXT);> > bsp_stack_abt_size = DEFINED (bsp_stack_abt_size) ? bsp_stack_abt_size : > 128;> > bsp_stack_fiq_size = DEFINED (bsp_stack_fiq_size) ? bsp_stack_fiq_size : > 128;> > bsp_stack_irq_size = DEFINED (bsp_stack_irq_size) ? bsp_stack_irq_size : > 256;> > bsp_stack_svc_size = DEFINED (bsp_stack_svc_size) ? bsp_stack_svc_size : > 256;> > bsp_stack_undef_size = DEFINED (bsp_stack_undef_size) ? > bsp_stack_undef_size : 128;> > /*> * BSP: Global symbols> */> bsp_ram_int_start = ORIGIN (RAM_INT);> bsp_ram_int_end = bsp_ram_int_start + bsp_ram_int_size;> > bsp_ram_ext_start = ORIGIN (RAM_EXT);> bsp_ram_ext_end = bsp_ram_ext_start + bsp_ram_ext_size;> > bsp_section_align = 16;> > bsp_stack_align = 16;> > SECTIONS {> .vector : {> /*> * BSP: Start of vector section> */> bsp_section_vector_start = .;> > /*> * BSP: Reserve space for the exception vector table and> * the pointers to the default exceptions handlers.> */> . = . + 64;> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of vector section> */> bsp_section_vector_end = .;> } > RAM_INT> > .text : {> /*> * BSP: Start of text section> */> bsp_section_text_start = .;> > /*> * BSP: System startup entry> */> KEEP (*(.entry))> > /*> * BSP: Moved into .text from .init> */> KEEP (*(.init))> > *(.text .stub .text.* .gnu.linkonce.t.*)> KEEP (*(.text.*personality*))> /* .gnu.warning sections are handled specially by elf32.em. */> *(.gnu.warning)> > /*> * BSP: Magic ARM stuff> */> *(.ARM.*)> *(.glue_7)> *(.glue_7t)> *(.vfp11_veneer)> > /*> * BSP: Special FreeBSD sysctl sections> */> . = ALIGN (16);> __start_set_sysctl_set = .;> *(set_sysctl_*);> __stop_set_sysctl_set = ABSOLUTE(.);> *(set_domain_*);> *(set_pseudo_*);> > /*> * BSP: Moved into .text from .*> */> *(.rodata .rodata.* .gnu.linkonce.r.*)> *(.rodata1)> *(.eh_frame_hdr)> > /*> * BSP: Required by cpukit/score/src/threadhandler.c> */> PROVIDE (_fini = .);> > /*> * BSP: Moved into .text from .fini> */> KEEP (*(.fini))> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of text section> */> bsp_section_text_end = .;> } > RAM_EXT> > .data : {> /*> * BSP: Start of data section> */> bsp_section_data_start = .;> > /*> * BSP: Moved into .data from .ctors> */> /* 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> 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))> > /*> * BSP: Moved into .data from .dtors> */> KEEP (*crtbegin.o(.dtors))> KEEP (*crtbegin?.o(.dtors))> KEEP (*(EXCLUDE_FILE (*crtend.o *crtend?.o ) .dtors))> KEEP (*(SORT(.dtors.*)))> KEEP (*(.dtors))> > /*> * BSP: Moved into .data from .*> */> *(.data1)> KEEP (*(.eh_frame))> *(.gcc_except_table .gcc_except_table.*)> KEEP (*(.jcr))> > *(.data .data.* .gnu.linkonce.d.*)> KEEP (*(.gnu.linkonce.d.*personality*))> SORT(CONSTRUCTORS)> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of data section> */> bsp_section_data_end = .;> } > RAM_EXT> > .bss : {> /*> * BSP: Start of bss section> */> bsp_section_bss_start = .;> > *(COMMON)> *(.dynbss)> *(.bss .bss.* .gnu.linkonce.b.*)> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of bss section> */> bsp_section_bss_end = .;> } > RAM_EXT> > .stack : {> /*> * BSP: Start of stack section> */> bsp_section_stack_start = .;> > . = ALIGN (bsp_stack_align);> bsp_stack_abt_start = .;> . = . + bsp_stack_abt_size;> > . = ALIGN (bsp_stack_align);> bsp_stack_fiq_start = .;> . = . + bsp_stack_fiq_size;> > . = ALIGN (bsp_stack_align);> bsp_stack_irq_start = .;> . = . + bsp_stack_irq_size;> > . = ALIGN (bsp_stack_align);> bsp_stack_svc_start = .;> . = . + bsp_stack_svc_size;> > . = ALIGN (bsp_stack_align);> bsp_stack_undef_start = .;> . = . + bsp_stack_undef_size;> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of stack section> */> bsp_section_stack_end = .;> } > RAM_INT> > .work_area : {> /*> * BSP: Start of work area. The work area will occupy the remaining> * RAM_EXT region and contains the RTEMS work space and heap. We > cannot> * assign the region end directly since this leads to a region full> * warning.> */> bsp_work_area_start = .;> > . = bsp_ram_ext_end - 4;> > . = ALIGN (bsp_section_align);> > /*> * BSP: End of work area> */> bsp_work_area_end = .;> } > RAM_EXT> > bsp_section_vector_size = bsp_section_vector_end - > bsp_section_vector_start;> > bsp_section_text_size = bsp_section_text_end - bsp_section_text_start;> > bsp_section_data_size = bsp_section_data_end - bsp_section_data_start;> > bsp_section_bss_size = bsp_section_bss_end - bsp_section_bss_start;> > bsp_section_stack_size = bsp_section_stack_end - bsp_section_stack_start;> > bsp_work_area_size = bsp_work_area_end - bsp_work_area_start;> > /* Stabs debugging sections. */> .stab 0 : { *(.stab) }> .stabstr 0 : { *(.stabstr) }> .stab.excl 0 : { *(.stab.excl) }> .stab.exclstr 0 : { *(.stab.exclstr) }> .stab.index 0 : { *(.stab.index) }> .stab.indexstr 0 : { *(.stab.indexstr) }> .comment 0 : { *(.comment) }> /* DWARF debug sections.> Symbols in the DWARF debugging sections are relative to the beginning> of the section so we begin them at 0. */> /* DWARF 1 */> .debug 0 : { *(.debug) }> .line 0 : { *(.line) }> /* GNU DWARF 1 extensions */> .debug_srcinfo 0 : { *(.debug_srcinfo) }> .debug_sfnames 0 : { *(.debug_sfnames) }> /* DWARF 1.1 and DWARF 2 */> .debug_aranges 0 : { *(.debug_aranges) }> .debug_pubnames 0 : { *(.debug_pubnames) }> /* DWARF 2 */> .debug_info 0 : { *(.debug_info .gnu.linkonce.wi.*) }> .debug_abbrev 0 : { *(.debug_abbrev) }> .debug_line 0 : { *(.debug_line) }> .debug_frame 0 : { *(.debug_frame) }> .debug_str 0 : { *(.debug_str) }> .debug_loc 0 : { *(.debug_loc) }> .debug_macinfo 0 : { *(.debug_macinfo) }> /* SGI/MIPS DWARF 2 extensions */> .debug_weaknames 0 : { *(.debug_weaknames) }> .debug_funcnames 0 : { *(.debug_funcnames) }> .debug_typenames 0 : { *(.debug_typenames) }> .debug_varnames 0 : { *(.debug_varnames) }> /* DWARF 3 */> .debug_pubtypes 0 : { *(.debug_pubtypes) }> .debug_ranges 0 : { *(.debug_ranges) }> .gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }> > /DISCARD/ : {> *(.note.GNU-stack) *(.gnu_debuglink)> }> > /*> * BSP: Catch all unknown sections> */> .nirvana : {> *(*)> } > NIRVANA> }> > -- > Sebastian Huber, Embedded Brains GmbH> > Address : Obere Lagerstr. 30, D-82178 Puchheim, Germany> Phone : +49 89 18 90 80 79-6> Fax : +49 89 18 90 80 79-9> E-Mail : sebastian.huber at embedded-brains.de> PGP : Public key available on request> > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.> _______________________________________________> rtems-users mailing list> rtems-users at rtems.com> http://rtems.rtems.org/mailman/listinfo/rtems-users
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