ARM Function Call in Assembly

Quotation:
This calling convention causes a "typical" ARM subroutine to:
- In the prolog, push r4 to r11 to the stack, and push the return address in r14, to the stack. (This can be done with a single STM instruction).
- copy any passed arguments (in r0 to r3) to the local scratch registers (r4 to r11).
- allocate other local variables to the remaining local scratch registers (r4 to r11).
- do calculations and call other subroutines as necessary using BL, assuming r0 to r3, r12 and r14 will not be preserved.
- put the result in r0
- In the epilog, pull r4 to r11 from the stack, and pulls the return address to the program counter r15. (This can be done with a single LDM instruction).


Reference:
http://en.wikipedia.org/wiki/Calling_convention#ARM
http://omappedia.org/wiki/Writing_ARM_Assembly#EABI_Calling_conventions
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042e/IHI0042E_aapcs.pdf