我使用 Eclipse 和 Yagarto 工具链（非 eabi，GCC 4.7.1）对 ARM 7 芯片（Atmel 的 AT91SAM7X256）进行编程，该项目的目标是将引导加载程序放置在定义的 ROM 范围内，稍后将其复制到 RAM 中（见下图，用于应用程序代码启动的 ROM 地址 0x104000 已修复）。按预期工作......直到您调试程序（SEGGER J-Link 和 GDB）。
内存结构图片显示在这里：http: //i47.tinypic.com/2vb6f7o.jpg（抱歉，不能在这里发布图片）。
问题从链接的 .text 部分开始，主要使用以下方法，该方法启动整个 .text 部分（正确）：（通过objdump -e -h common/exhandler.o > exhandler.lst反汇编 C 代码）
00000000 <EXHANDLER_printHex>:
0: e92d4038 push {r3, r4, r5, lr}
4: e1a05000 mov r5, r0
8: e3a0401c mov r4, #28
c: e1a03435 lsr r3, r5, r4
10: e203000f and r0, r3, #15
14: e3500009 cmp r0, #9
18: c2800027 addgt r0, r0, #39 ; 0x27
1c: e2800030 add r0, r0, #48 ; 0x30
20: ebfffffe bl 0 <DBGUNIT_sendCharacter>
24: e2444004 sub r4, r4, #4
28: e3740004 cmn r4, #4
2c: 1afffff6 bne c <EXHANDLER_printHex+0xc>
30: e8bd4038 pop {r3, r4, r5, lr}
34: e12fff1e bx lr
反汇编链接的ELF文件时，代码输出为：（错误）
00104000 <EXHANDLER_printHex>:
104000: e92d4038 push {r3, r4, r5, lr}
104004: 5000 str r0, [r0, r0]
104006: 401ce1a0 andsmi lr, ip, r0, lsr #3
10400a: e3a0 b.n 10474e <ADCDAC_get16BitChannel+0x82>
10400c: e1a03435 .word 0xe1a03435
104010: e203000f and r0, r3, #15
104014: e3500009 cmp r0, #9
104018: 0027 movs r7, r4
10401a: 0030c280 eorseq ip, r0, r0, lsl #5
10401e: e280 b.n 104522 <CSTARTUP_lowLevelInit+0xfa>
104020: eb003367 bl 110dc4 <__DBGUNIT_sendCharacter_from_arm>
104024: 4004 ands r4, r0
104026: e244 .short 0xe244
104028: e3740004 cmn r4, #4
10402c: 1afffff6 .word 0x1afffff6
104030: e8bd4038 pop {r3, r4, r5, lr}
104034: e12fff1e .word 0xe12fff1e
虽然字节序列保持不变，但这些 ASM 命令的解释不同。我的假设是 Thumb 和 ARM 代码在链接过程中出现问题。
我的链接器文件：
/*
* Linker script for AT91SAM7X256 with internal bootloader.
*
* Bootloader is put into first 16 kB of Flash, then loaded to RAM and will connect by DBGU UART interface
* (115 kBaud, no parity bit).
*/
OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
OUTPUT_ARCH(arm)
MEMORY
{
flash-boot (rx) : ORIGIN = 0x00100000, LENGTH = 16K /* read-only flash memory for boot-loader and startup sequence */
flash-app (rx) : ORIGIN = 0x00104000, LENGTH = 240K /* read-only flash memory for application */
ram (rwx) : ORIGIN = 0x00200000, LENGTH = 64K /* read/write S-RAM memory */
}
/* Stack is growing backwards, starting at end of RAM and is aligned at 4 byte. First entry in stack will
use RAM address 0x20fffc to 0x20ffff. */
_estack = 0x20fffc;
SECTIONS
{
. = 0;
/* Elements required during start-up sequence. Must be first elements in ROM. */
.startup : {
obj/sys/startup.o(.text .rodata)
. = ALIGN(4);
obj/sys/swi_handler.o(.text .rodata)
. = ALIGN(4);
_estartup = .; /* end of startup segment */
} >flash-boot
.ramvect : { /* used for vectors remapped to RAM */
__ram_start = .;
. = 0x40;
} >ram
/* Further elements for bootloader, which are placed into RAM for allowing chip flash. */
.bootloader : {
_bootloader = .; /* RAM */
obj/comm/dbgunit.o(.text .rodata)
. = ALIGN(4);
_ebootloader = .; /* RAM */
} >ram AT>flash-boot
/* Code starts at fixed address in flash (application start) and is kept there. */
.text : {
CREATE_OBJECT_SYMBOLS
*(.text .text.* .gnu.linkonce.t.*) /* remaining code */
*(.plt)
*(.gnu.warning)
*(.glue_7) *(.glue_7t) /* stub for code which glues together ARM7 and Thumb code */
. = ALIGN(4);
*(.rodata .rodata.* .gnu.linkonce.r.*) /* read-only data (constants) */
*(.ARM.extab* .gnu.linkonce.armextab.*)
*(.gcc_except_table)
*(.init)
*(.fini)
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array))
PROVIDE_HIDDEN (__preinit_array_end = .);
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
PROVIDE_HIDDEN (__init_array_end = .);
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(.fini_array))
KEEP (*(SORT(.fini_array.*)))
PROVIDE_HIDDEN (__fini_array_end = .);
. = ALIGN(4);
} >flash-app
/* .ARM.exidx is sorted, so has to go in its own output section. */
.ARM.exidx : {
__exidx_start = .;
*(.ARM.exidx* .gnu.linkonce.armexidx.*)
__exidx_end = .;
} >flash-app
_etext = .;
/* Initialized .data sections go into RAM. */
.data :
{
_data = .; /* create a global symbol marking the start of the .data section (RAM) */
*(.ramsection .ramsection.*)
. = ALIGN(4);
*(.data .data.* .gnu.linkonce.d.*)
. = ALIGN(4);
_edata = .; /* define a global symbol marking the end of the .data section */
} >ram AT>flash-app /* put all the above into RAM */
/* Uninitialized .bss sections go into RAM. */
.bss (NOLOAD):
{
__bss_start__ = .; /* define a global symbol marking the start of the .bss section */
*(.bss .bss.* .gnu.linkonce.b.*)
*(COMMON)
. = ALIGN(4);
} > ram /* put all the above in RAM (it will be cleared in the startup code */
_bss_end = . ;
__bss_end__ = . ; /* define a global symbol marking the end of the .bss section */
. = ALIGN(4); /* advance location counter to the next 32-bit boundary */
_end = .; /* define a global symbol marking the end of application RAM */
PROVIDE (end = .);
/* 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) }
.note.gnu.arm.ident 0 : { KEEP (*(.note.gnu.arm.ident)) }
.ARM.attributes 0 : { KEEP (*(.ARM.attributes)) }
/DISCARD/ : { *(.note.GNU-stack) }
}
谁能发现链接器文件中的错误或给我提示，下一步该去哪里看？
谢谢你的阅读，保尔
PS：这是 ELF 文件部分标题的一些输出，因此很明显没有重叠部分。
Sections:
Idx Name Size VMA LMA File off Algn
0 .startup 0000033c 00100000 00100000 00008000 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .ramvect 00000040 00200000 00200000 00030000 2**0
ALLOC
2 .bootloader 000001cc 00200040 0010033c 00010040 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
3 .text 0000ce08 00104000 00104000 00014000 2**3
CONTENTS, ALLOC, LOAD, READONLY, CODE
4 .ARM.exidx 000000f0 00110e08 00110e08 00020e08 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
5 .data 0000129c 00200210 00110ef8 00028210 2**3
CONTENTS, ALLOC, LOAD, DATA
6 .bss 000008c8 002014ac 00112194 000294ac 2**2
ALLOC
7 .debug_aranges 000009b8 00000000 00000000 000294b0 2**3
CONTENTS, READONLY, DEBUGGING
8 .debug_info 0002166d 00000000 00000000 00029e68 2**0
CONTENTS, READONLY, DEBUGGING
9 .debug_abbrev 00006cb4 00000000 00000000 0004b4d5 2**0
CONTENTS, READONLY, DEBUGGING
10 .debug_line 00007db7 00000000 00000000 00052189 2**0
CONTENTS, READONLY, DEBUGGING
11 .debug_frame 0000232c 00000000 00000000 00059f40 2**2
CONTENTS, READONLY, DEBUGGING
12 .debug_str 0000682a 00000000 00000000 0005c26c 2**0
CONTENTS, READONLY, DEBUGGING
13 .debug_loc 00016421 00000000 00000000 00062a96 2**0
CONTENTS, READONLY, DEBUGGING
14 .comment 00000011 00000000 00000000 00078eb7 2**0
CONTENTS, READONLY
15 .ARM.attributes 0000002e 00000000 00000000 00078ec8 2**0
CONTENTS, READONLY
16 .debug_ranges 00000968 00000000 00000000 00078ef6 2**0
CONTENTS, READONLY, DEBUGGING