A small setup that I used to learn X86_x64 shellcode generation using ASM and compiled C code.

Please ensure you have the following installed before starting to build.

- Install XCode: `xcode-select --install`

- Install Brew: `/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"`

- Install Brew GCC: `brew install gcc`

static volatile int myexec(char * arg1, long arg2, long arg3) {

/*

// int a=10, b;

// asm ("movl %1, %%eax;

// movl %%eax, %0;"

// :"=r"(b) /* output */

// :"r"(a) /* input */

// :"%eax" /* clobbered register */

// );

volatile int x = 0;

int y = 0x200003b;

asm volatile( "movq %4,%%rax;\n\t"

"movq %1,%%rdi;\n\t"

"mov %2,%%rsi;\n\t"

"mov %3,%%rdx;\n\t"

"syscall"

:"=g"(x)

:"g"(arg1),"g"(arg2),"g"(arg3),"g"(y)

:"%rcx", "%r11", "%rax", "%rdi", "%rsi", "%rdx"

);

return x;

}

int main1(char* mystring) {

// char mystring[] = {'/','b','i','n','/','s','h',0};

//seteuid(0);

//fork();

// write(1,mystring,8); //size_t write(int fildes, const void *buf, size_t nbytes);

//system ("ls");

// char* command="/bin/sh"

myexec(mystring, 0, 0);

return 0;

}