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Code: Select all

%macro isr 2
align 8
global _isr_%1
_isr_%1:
        push 0
        pushaq
        mov rdi, %2
        mov rsi, rsp
        call fault_handler
        popaq
        add rsp,8
        iretq
%endmacro

section .text

extern fault_handler;

isr         divide_error, 0
isr         debug, 1
isr         nmi_interrupt, 2
isr         breakpoint, 3

Code: Select all

struct interrupt_state {
    uint64_t r15,r14,r13,r12,r11,r10;
    uint64_t r9,r8,rsi,rdi,rdx,rcx;
    uint64_t rbx,rax,rbp,errorCode;
    uint64_t rip, cs, rflags, rsp;
} __attribute__((packed));

void fault_handler(int num, struct interrupt_state* state) {
    if(gdbDebugInitialized) {
        gdbHandleException(num, state);
        return;
    }
//Left out some code here since it will never be called while the stub is active
}

Code: Select all

void gdbHandleException(int num, struct interrupt_state* state) {
    if(gdbInMemoryRoutine) {
        gdbErrorOccurred = true;
        return;
    }

    int sigval = computeSignal(num);
...
//Left out all code starting the loop and reading packages since the debug packages themselves are being read correctly
...

        case 's':
            stepping = true;
        case 'c':
            /* try to read optional parameter, pc unchanged if no parm */
            if (hexToInt (&ptr, &addr)) {
                state->rip = addr;
            }

            /* clear the trace bit */
            state->rflags &= 0xfffffeff;

            /* set the trace bit if we're stepping */
            //if (stepping) //Commented out so that we are always setting the flag after breakpoint (To see whether it still stops after each instruction)
                state->rflags |= 0x100;

            return;