can you explain this assembly code
.string "Hello world\n"
.type _start, @function
mov x8, #64
mov x0, #1
adr x1, .hello
mov x2, #12
mov x8, #93
This assembly code appears to be for a 64-bit ARM processor and uses the Linux ABI. It is defining a string called “.hello” containing the text “Hello world\n”. It is then aligning the string on a 4-byte boundary.
The code then defines a global function called “_start” and specifies its type as a function.
In the _start function, the code performs the following actions:
- It moves the value 64 into register x8.
- It moves the value 1 into register x0.
- It loads the address of the .hello string into register x1.
- It moves the value 12 into register x2.
- It performs a system call with the number 0. This is likely the write system call, which writes data to a file descriptor. The values in registers x0, x1, and x2 are likely the file descriptor, the address of the data to write, and the length of the data, respectively.
- It moves the value 93 into register x8.
- It performs another system call with the number 0. This is likely the exit system call, which terminates the process with the specified exit code. The value in register x8 is likely the exit code.