Yes this instruction should move absolute hardcoded data embedded into instruction itself into register, or data from absolute address. But I got into this instruction only recently when I wanted to know where constant data for initialization of local variables are because I didnt find them in .rodata ELF section.

So basically GCC uses this instruction to initialize automatic variables on stack!

Lets dive into code to find out how this instruction is used. As we see in this code example we have local variable test initialized:

We know that local variables are put in stack and I was interested to know where and how local variables get initialized.

When we dump .text section with objdump we see that this constant 0x41414141414141 is realy embedded in the code itself:

As we see disassembled function and register content from GDB:

So when we look at code we see that this string test, in HEX notation 0x0x41414141414141 is hardcoded in movabs instruction, and is put in rax register, and then content of rax register is put on address in rbp minus offset 0x10:

So this local string will be placed on address 0x7fffffffdde0 - 0x10 We see that this local string is placed in stack frame of function on address 0x7fffffffddd0, and this we see when we dump the stack:

So we ended with initialized local string on a stack just as we expected.