Gcc Gdb在调试ARM7微控制器的汇编程序时跳过源代码行

我在调试用汇编语言为ARM7微控制器（AT91SAM7S64）编写的简单程序时遇到问题。我使用gcc、gdb和OpenOCD。 我的程序已正确加载到目标，工作正常（led闪烁）。但当我调用“next”命令时，gdb跳过了某些源代码行

以下是一段源代码：

    Reset_Handler:

                LDR     R0, =0x0100
                LDR     R1, =PIOA_PER
                STR     R0, [R1]

                LDR     R1, =PIOA_OER
                STR     R0, [R1]
uuu:
                bl      wait;
                LDR     R1, =PIOA_SODR
                STR     R0, [R1]
uuu1:
                bl      wait;
                LDR     R2, =PIOA_CODR
                STR     R0, [R2]
                b       uuu;
@ one second delay
wait:
    .............
    .............

        .end

为了获得gdb输出（见下文），我使用了“目标sim”而不是真实目标，但结果完全相同

(gdb) target sim
Connected to the simulator.
(gdb) load
Loading section .text, size 0xc8 vma 0x100000
Start address 0x100000
Transfer rate: 1600 bits in <1 sec.
(gdb) b Reset_Handler
Breakpoint 1 at 0x100064: file main.s, line 59.
(gdb) run
Starting program: C:\Arm\Projects\Asm/./main.elf

Breakpoint 1, Reset_Handler () at main.s:60
60                                      LDR             R1, =PIOA_PER
(gdb) n
61                                      STR             R0, [R1]
(gdb) n
63                                      LDR             R1, =PIOA_OER
(gdb) n
64                                      STR             R0, [R1]
(gdb) n
uuu () at main.s:66
66                                      bl              wait;
(gdb) n
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) n     <<<<<--------- Here the problem begins
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) n
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) stepi <<<<<------ Doing a 'stepi' command allows to pass below 'uuu1' label
uuu1 () at main.s:70
70                                      bl              wait;
(gdb) n
71                                      LDR             R2, =PIOA_CODR
(gdb) n
72                                      STR             R0, [R2]
(gdb) n
73                                      b               uuu;
(gdb) n     <<<<<--------- Here the problem begins again
71                                      LDR             R2, =PIOA_CODR
(gdb) n
72                                      STR             R0, [R2]
(gdb) n
73                                      b               uuu;
(gdb) n
71                                      LDR             R2, =PIOA_CODR
(gdb) where
#0  uuu1 () at main.s:71
#1  0x00100084 in uuu1 () at main.s:70
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)

我的生成文件：

TRGT = arm-none-eabi-
CC   = $(TRGT)gcc
CP   = $(TRGT)objcopy
AS   = $(TRGT)gcc -x assembler-with-cpp
#AS   = $(TRGT)as
LD   = $(TRGT)ld
OBJDUMP = $(TRGT)objdump
LD_SCRIPT = main.ld
MCU      = arm7tdmi

#DEBUG = stabs
DEBUG = dwarf-2
ASFLAGS = -mcpu=$(MCU) -g$(DEBUG)
LDFLAGS = -T $(LD_SCRIPT)

all: main.elf main.lss
    @echo Done!

main.elf : main.o 
    @echo Linking $<
    $(CC) -nostartfiles $(LDFLAGS) $< -o $@

main.o : main.s
    @echo Compiling $<
    $(AS) -c $(ASFLAGS) $< -o $@

TRGT=arm none eabi-
CC=$（TRGT）gcc
CP=$（TRGT）对象复制
AS=$（TRGT）带cpp的gcc-x汇编程序
#AS=$（TRGT）AS
LD=$（TRGT）LD
OBJDUMP=$（TRGT）OBJDUMP
LD_SCRIPT=main.LD
MCU=arm7tdmi
#调试=插入
调试=dwarf-2
ASFLAGS=-mcpu=$（MCU）-g$（调试）
LDFLAGS=-T$（LD_脚本）
全部：main.elf main.lss
@回音完毕！
main.elf:main.o
@回音链接$<
$（CC）-nostartfiles$（LDFLAGS）$<-o$@
梅因：梅因
@回声编译$<
$（AS）-c$（ASFLAGS）$<-o$@

提前感谢您的帮助

在有问题的代码段中尝试使用“si”而不是n

“n”或多或少是下一条语句，“si”是下一条asm指令

---

如果asm片段的调试代码不正确，“si”可能仍然允许您单步执行它，利用在本例中的“语句”和“汇编程序”这一事实级别相同。

使用

ni

而不是

next

和

si

而不是通过汇编程序指令执行

step

。

我知道这有点旧，但您应该尝试向编译器添加

-O0

标志。我阻止gcc进行任何优化，这可能会导致您遇到的问题。

是的，它可以工作（请参阅上面gdb日志中的我的评论）。但is的作用是“跨入”而不是“跨过”。我希望gdb能像在第66行那样跳过“等待”过程。我计划在Eclipse中使用gdb，这对我来说是非常恼人的效果。为什么“针对asm的调试代码”可能不正确？也许gdb或gcc有什么“神奇”的兼容性争论？我猜gcc中有bug。调试信息不与行同步。也许你可以试着强迫侏儒

(gdb) target sim
Connected to the simulator.
(gdb) load
Loading section .text, size 0xc8 vma 0x100000
Start address 0x100000
Transfer rate: 1600 bits in <1 sec.
(gdb) b Reset_Handler
Breakpoint 1 at 0x100064: file main.s, line 59.
(gdb) run
Starting program: C:\Arm\Projects\Asm/./main.elf

Breakpoint 1, Reset_Handler () at main.s:60
60                                      LDR             R1, =PIOA_PER
(gdb) n
61                                      STR             R0, [R1]
(gdb) n
63                                      LDR             R1, =PIOA_OER
(gdb) n
64                                      STR             R0, [R1]
(gdb) n
uuu () at main.s:66
66                                      bl              wait;
(gdb) n
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) n     <<<<<--------- Here the problem begins
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) n
67                                      LDR             R1, =PIOA_SODR
(gdb) n
68                                      STR             R0, [R1]
(gdb) stepi <<<<<------ Doing a 'stepi' command allows to pass below 'uuu1' label
uuu1 () at main.s:70
70                                      bl              wait;
(gdb) n
71                                      LDR             R2, =PIOA_CODR
(gdb) n
72                                      STR             R0, [R2]
(gdb) n
73                                      b               uuu;
(gdb) n     <<<<<--------- Here the problem begins again
71                                      LDR             R2, =PIOA_CODR
(gdb) n
72                                      STR             R0, [R2]
(gdb) n
73                                      b               uuu;
(gdb) n
71                                      LDR             R2, =PIOA_CODR
(gdb) where
#0  uuu1 () at main.s:71
#1  0x00100084 in uuu1 () at main.s:70
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)