Assistance Required for QEMU Hardfault Error with Cortex-M33 on MPS2AN505

[sanjana gogte]

I hope this message finds you well. I am reaching out to seek your expertise regarding a persistent issue I have encountered while working with QEMU, specifically a hardfault error when emulating the MPS2AN505 with a Cortex-M33 core. 

I have been grappling with this issue for some time and am unsure of the next steps to take. Could you please advise on potential areas to investigate or adjustments that might resolve this error? I am particularly curious if the issue lies with the vector table placement or the configuration in my linker script.

The error I am facing is as follows:
qemu: fatal: Lockup: can't escalate 3 to HardFault (current priority -1)

This occurs when I attempt to run my kernel.elf file using the following QEMU command:

qemu-system-arm -machine mps2-an505 -cpu cortex-m33 \
                -m 16M \
                -nographic -serial mon:stdio \
                -device loader,file=kernel.elf

For your reference, here are the relevant details of my setup:

Startup File (Boot.s)

.thumb
.section .isr_vector
    .long    __StackTop         /* Initial Top of Stack */
    .long    Reset_Handler      /* Reset Handler */

.text
.global Reset_Handler
Reset_Handler:  
    ldr     R0, = main

bx      R0

Linker Script (Kernel.ld)

MEMORY
{
   NS_CODE (rx)     : ORIGIN = 0x00000000, LENGTH = 512K
   S_CODE_BOOT (rx) : ORIGIN = 0x10000000, LENGTH = 512k
   RAM   (rwx) : ORIGIN = 0x20000000, LENGTH = 512k
}

/* Entry Point */
ENTRY(Reset_Handler)

SECTIONS
{
    .text :
    {
        KEEP(*(.isr_vector))
        *(.text)
        *(.data)
        *(.bss)
    } > S_CODE_BOOT
    /* Set stack top to end of S_CODE_BOOT. */
    __StackTop = ORIGIN(S_CODE_BOOT) + LENGTH(S_CODE_BOOT);
}

Toolchain Used:

arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi

Compilation Commands to generate my elf file:

arm-none-eabi-gcc -mcpu=cortex-m33 -g -c boot.s -o boot.o
arm-none-eabi-ld boot.o main.o -T kernel.ld -o kernel.elf
arm-none-eabi-objdump -d kernel.elf > kernel.list
arm-none-eabi-objdump -t kernel.elf | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$/d' > kernel.sym
arm-none-eabi-readelf -A kernel.elf

Main Function (main.c):

void main(void)
{
    while (1);
}

Output of readelf -wl Command:

Elf file type is EXEC (Executable file)
Entry point 0x10000008
There is 1 program header, starting at offset 52

Program Headers:
  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x001000 0x10000000 0x10000000 0x00016 0x00016 R E 0x1000

 Section to Segment mapping:
  Segment Sections...
   00     .text

Guest Errors Observed:

Invalid read at addr 0x10000000, size 4, region '(null)', reason: rejected
Invalid read at addr 0x10000004, size 4, region '(null)', reason: rejected

Your guidance on this matter would be greatly appreciated. I am eager to understand and resolve this issue, and I believe your expertise could be invaluable in this context.

Thank you for your time and consideration. I look forward to any insights or suggestions you might have.

Best regards,
Sanjana Gogte