Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 168

AGB Programming Manual
7) Monitor ROM does the system call operation (1), and loads to the
system call stack.
USR Stack
03007F00
LR_usr
R2
Save with each
System Call
User Interrupt
Processing
8) Switch the CPU Mode to System Mode (privileged user mode).
9) Monitor ROM does the same operation as (3), and loads to the user
stack.
USR Stack
03007F00
LR_usr
R2
Save with each
System Call
User Interrupt
Processing
LR_usr
R2
Save with each
System Call
10) Complete processing with each system call.
USR Stack
03007F00
LR_usr
R2
Save with each
System Call
User Interrupt
Processing
11) Return value to registers R0, R1, and R3, in cases where a system
call provides a return value, and then return to the user interrupt
processing.
USR Stack
03007F00
LR_usr
R2
Save with each
System Call
User Interrupt
Processing
©1999 - 2001 Nintendo of America Inc.
IRQ Stack
03007FA0
6 WORDS
03007F00
SP_usr
IRQ Stack
03007FA0
6 WORDS
SP_usr
03007F00
IRQ Stack
03007FA0
6 WORDS
03007F00
SP_usr
IRQ Stack
03007FA0
6 WORDS
03007F00
SP_usr
168
SVC Stack
03007FE0
4 WORDS
SP_irq
4 WORDS
03007FA0
SVC Stack
03007FE0
4 WORDS
SP_irq
4 WORDS
03007FA0
SVC Stack
03007FE0
4 WORDS
SP_irq
4 WORDS
03007FA0
SVC Stack
03007FE0
4 WORDS
SP_irq
03007FA0
D.C.N. AGB-06-0001-002B4
AGB System Calls
SP_svc
SP_svc
SP_svc
SP_svc