PAD dr

#   PSX kernel/bios function: PAD_dr 
#   Gets controller button state
#       Returns:
#           r2 = (Button state)
#           *0x80032a78 = (Button state)
#           Button state definition: Halfword (2-byte) value; for each bit, 1 means button is not pressed, 0 means it is pressed
#               0x8000  Left
#               0x4000  Down
#               0x2000  Right
#               0x1000  Up
#               0x0800  Start
#               0x0400  R3
#               0x0200  L3
#               0x0100  Select
#               0x0080  Square
#               0x0040  X
#               0x0020  Circle
#               0x0010  Triangle
#               0x0008  R1
#               0x0004  L1
#               0x0002  R2
#               0x0001  L2

80021ff4: 240a00b0 addiu r10,r0,0x00b0
80021ff8: 01400008 jr r10
80021ffc: 24090016 addiu r9,r0,0x0016