$($c$)$ Listing Q$3$a is the assembly language code for a version of the memcpy function commonly used in C programs. The function copies $$n$$ bytes from the source location $($src$)$ to the destination location $($dest$).$

a$.$ What happens when each line of this function is executed?

$[10$ marks$]$

b$.$ Identify an example of each of the following addressing modes in this function:

i$.$ Immediate

ii$.$ Register indirect

$[4$ marks$]$

c$.$ If the stack pointer contains $0$x$20002000$ on entry to this function, what address will the PUSH instruction save a copy of the link register to$?$

$[2$ marks$]$

d$.$ You have a $32$ byte block of data at memory address $0$x$20000100$ that you would like to copy to address $0$x$20000200.$ How would you set up the registers and call upon this function to do this for you.

$[6$ marks$]$

e$.$ How would you modify this function so that it returns the address of the destination buffer in R$0.$

$[5$ marks$]$