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I'm working through an example in the book Embedded Programming with Android:

/*****************************************************************************/
    .syntax unified
    .cpu arm7tdmi
    .fpu softvfp

/******************************************************************************
 *
 * This is the code that gets called when the processor first starts execution
 * following a reset event.
 *
*******************************************************************************/
    .section    .text.ResetISR,"ax",%progbits
    .align  2
    .global ResetISR
    .type   ResetISR, %function
ResetISR:
    mov   r0, #5         @ Load register r0 with the value 5
    mov   r1, #4         @ Load register r1 with the value 4
    add   r2, r1, r0     @ Add r0 and r1 and store in r2
ResetISR_STOP:
    b   ResetISR_STOP    @ Infinite loop to stop execution
    .size   ResetISR, .-ResetISR

Source: https://github.com/shugaoye/bo/blob/master/c03/c03e1/c03e1.S

The output from building is as follows:

$ make DEBUG=1 VERBOSE=1
arm-none-eabi-gcc -marm -mno-thumb-interwork -mabi=aapcs-linux 
   -march=armv5te -fno-common -ffixed-r8 -msoft-float -fno-builtin 
   -ffreestanding -MD -g -D DEBUG -Dgcc -o gcc/c03e1.o -c c03e1.S

arm-none-eabi-ld -T c03e1.ld --entry ResetISR 
   -o gcc/c03e1.axf gcc/c03e1.o /opt/ 
   arm-2012.03/bin/../lib/gcc/arm-none-eabi/4.6.3/../../../../arm-none-eabi/lib/  libm.a 
   /opt/arm-2012.03/bin/../lib/gcc/arm-none-eabi/4.6.3/../../../../arm-none- eabi/lib/libc.a
   /opt/arm-2012.03/bin/../lib/gcc/arm-none-eabi/4.6.3/libgcc.a

I then run the android emulator as follows:

 emulator -verbose -show-kernel -netfast -avd hd2 -shell -qemu -s -S –kernel gcc/c03e1.axf

Next I connect with ddd:

 ddd --debugger arm-none-eabi-gdb gcc/c03e1.axf

When I open the the machine code window view in ddd I see the following error:

Dump of assembler code from 0x10000 to 0x10100:
0x00010000 <ResetISR+0>:     mov     r0, #5
0x00010004 <ResetISR+4>:     mov     r1, #4
0x00010008 <ResetISR+8>:     add     r2, r1, r0
0x0001000c <ResetISR_STOP+0>:        b       0x1000c <ResetISR_STOP>
0x00010010:  Cannot access memory at address 0x10010

I've seen similar posts (e.g. android gdb error,"Cannot access memory at address"), but no posts using the same code or environment as me.

Any ideas?

NOTE: The avd is setup with:

  • Target: Android 4.03
  • CPU/API: armeabi-v7a
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Chris Snow
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  • Note that there isn't anything meaningful to disassemble at that address anyway (it's past the end of your actual code), so you're not missing much in this particular case. Unrelatedly, it raises an eyebrow to see apparently three different CPU settings in play here - that's the kind of thing which could lead to problems with real non-trivial code; it would be wise to work out what you're _actually_ targeting - ARM7TDMI (ARMv4t architecture), ARMv5te architecture (ARM9 and friends), or ARMv7-A architecture (Cortex-A and friends) - and get all the relevant settings aligned appropriately. – Notlikethat Oct 09 '15 at 11:28
  • The android emulator CPU/API is defined in the book to use armeabi-v7a, so is that ARMv7-A? – Chris Snow Oct 09 '15 at 12:29

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