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dolphin/docs/codehandler.s

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#MIT License
#Copyright (c) 2010-2017 Nuke, brkirch, Y.S, Kenobi, gamemasterplc
#Permission is hereby granted, free of charge, to any person obtaining a copy
#of this software and associated documentation files (the "Software"), to deal
#in the Software without restriction, including without limitation the rights
#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#copies of the Software, and to permit persons to whom the Software is
#furnished to do so, subject to the following conditions:
#The above copyright notice and this permission notice shall be included in all
#copies or substantial portions of the Software.
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
#SOFTWARE.
# Based off of codehandleronly.s from Gecko OS source code.
# Example command to build:
# powerpc-elf-gcc -mpowerpc -mpaired -mbig codehandler.s -nostartfiles -nodefaultlibs -nostdlib -T codehandler.ld -o codehandler.bin
.text
#Register Defines
.set r0,0; .set r1,1; .set r2,2; .set r3,3; .set r4,4
.set r5,5; .set r6,6; .set r7,7; .set r8,8; .set r9,9
.set r10,10; .set r11,11; .set r12,12; .set r13,13; .set r14,14
.set r15,15; .set r16,16; .set r17,17; .set r18,18; .set r19,19
.set r20,20; .set r21,21; .set r22,22; .set r23,23; .set r24,24
.set r25,25; .set r26,26; .set r27,27; .set r28,28; .set r29,29
.set r30,30; .set r31,31; .set f0,0; .set f2,2; .set f3,3
.globl _start
gameid:
.long 0,0
cheatdata:
.long frozenvalue
.space 39*4
# Warning, _strip_and_align expects cheat codes to start on 0x0 or 0x8.
# Properly compiling it will add a nop if needed.
_start:
stwu r1,-172(r1) # stores sp
stw r0,8(r1) # stores r0
mflr r0
stw r0,176(r1) # stores lr
mfcr r0
stw r0,12(r1) # stores cr
mfctr r0
stw r0,16(r1) # stores ctr
mfxer r0
stw r0,20(r1) # stores xer
stmw r3,24(r1) # saves r3-r31
mfmsr r25
stw r25,168(r1) # save msr
ori r26,r25,0x2000 #enable floating point ?
andi. r26,r26,0xF9FF
mtmsr r26
stfd f2,152(r1) # stores f2
stfd f3,160(r1) # stores f3
lis r31,cheatdata@h #0x8000
lis r20, 0xCC00
lhz r28, 0x4010(r20)
ori r21, r28, 0xFF
sth r21, 0x4010(r20) # disable MP3 memory protection
lis r15, codelist@h
ori r15, r15, codelist@l
ori r7, r31, cheatdata@l # set pointer for storing data (before the codelist)
lis r6,0x8000 # default base address = 0x80000000 (code handler)
mr r16,r6 # default pointer =0x80000000 (code handler)
li r8,0 # code execution status set to true (code handler)
lis r3,0x00D0
ori r3,r3,0xC0DE
lwz r4,0(r15)
cmpw r3,r4
bne- _exitcodehandler
lwz r4,4(r15)
cmpw r3,r4
bne- _exitcodehandler # lf no code list skip code handler
addi r15,r15,8
b _readcodes
_exitcodehandler:
sth r28,0x4010(r20) # restore memory protection value
lfd f2,152(r1) # loads f2
lfd f3,160(r1) # loads f3
lwz r25,168(r1)
mtmsr r25
lwz r0,176(r1)
mtlr r0 # restores lr
lwz r0,12(r1)
mtcr r0 # restores cr
lwz r0,16(r1)
mtctr r0 # restores ctr
lwz r0,20(r1)
mtxer r0 # restores xer
lmw r3,24(r1) # restores r3-r31
lwz r0,8(r1) # loads r0
addi r1,r1,172
isync
blr # return back to game
_readcodes:
lwz r3,0(r15) #load code address
lwz r4,4(r15) #load code value
addi r15,r15,8 #r15 points to next code
andi. r9,r8,1
cmpwi cr7,r9,0 #check code execution status in cr7. eq = true, ne = false
li r9,0 #Clears r9
rlwinm r10,r3,3,29,31 #r10 = extract code type, 3 bits
rlwinm r5,r3,7,29,31 #r5 = extract sub code type 3 bits
andis. r11,r3,0x1000 #test pointer
rlwinm r3,r3,0,7,31 #r3 = extract address in r3 (code type 0/1/2) #0x01FFFFFF
bne +12 #jump lf the pointer is used
rlwinm r12,r6,0,0,6 #lf pointer is not used, address = base address
b +8
mr r12,r16 #lf pointer is used, address = pointer
cmpwi cr4,r5,0 #compares sub code type with 0 in cr4
cmpwi r10,1
blt+ _write #code type 0 : write
beq+ _conditional #code type 1 : conditional
cmpwi r10,3
blt+ _ba_pointer #Code type 2 : base address operation
beq- _repeat_goto #Code type 3 : Repeat & goto
cmpwi r10,5
blt- _operation_rN #Code type 4 : rN Operation
beq+ _compare16_NM_counter #Code type 5 : compare [rN] with [rM]
cmpwi r10,7
blt+ _hook_execute #Code type 6 : hook, execute code
b _terminator_onoff_ #code type 7 : End of code list
_Write_32:
lwz r18, 0(r12) #Load data from registry that will be written to
cmpw r18, r5 #Is data to be written equal to the data in memory
beq+ +72 #Skip if yes
stw r5, 0(r12) #store opcode
li r9, 0 #safe, check r9 if more write_32's are linked.
b +48
_Write_08x:
lbzx r18, r9, r12
rlwinm r0, r4, 0, 24,31 #Clears any other data with r4's byte, for compare
cmpw r0, r18
beq+ +44
stbx r4,r9,r12
b +24
_Write_16x:
lhzx r18, r9, r12
rlwinm r0, r4, 0, 16,31 #Makes sure r4 is just a halfword for compare
cmpw r0, r18
beq+ +20
sthx r4,r9,r12
icbi r9, r12 #branch target. Clears cache. Need dcbf?
sync
isync
blr
#CT0=============================================================================
#write 8bits (0): 00XXXXXX YYYY00ZZ
#write 16bits (1): 02XXXXXX YYYYZZZZ
#write 32bits (2): 04XXXXXX ZZZZZZZZ
#string code (3): 06XXXXXX YYYYYYYY, d1d1d1d1 d2d2d2d2, d3d3d3d3 ....
#Serial Code (4): 08XXXXXX YYYYYYYY TNNNZZZZ VVVVVVVV
_write:
add r12,r12,r3 #address = (ba/po)+(XXXXXX)
cmpwi r5,3
beq- _write_string #r5 == 3, goto string code
bgt- _write_serial #r5 >= 4, goto serial code
bne- cr7,_readcodes #lf code execution set to false skip code
cmpwi cr4,r5,1 #compares sub code type and 1 in cr4
bgt- cr4,_write32 #lf sub code type == 2, goto write32
#lf sub code type = 0 or 1 (8/16bits)
rlwinm r10,r4,16,16,31 #r10 = extract number of times to write (16bits value)
_write816:
beq cr4,+16 #lf r5 = 1 then 16 bits write
bl _Write_08x
addi r9,r9,1
b +12
bl _Write_16x
addi r9, r9, 2
subic. r10,r10,1 #number of times to write -1
bge- _write816
b _readcodes
_write32:
rlwinm r12,r12,0,0,29 #32bits align adress
mr r5, r4
bl _Write_32
b _readcodes
_write_string: #endianess ?
mr r9,r4
mr r22, r4
bne- cr7,_skip_and_align #lf code execution is false, skip string code data
_stb:
subic. r9,r9,1 #r9 -= 1 (and compares r9 with 0)
blt- _skip_and_align #lf r9 < 0 then exit
lbzx r5,r9,r15
mr r4, r5
bl _Write_08x #loop until all the data has been written
mr r4, r22
b _stb
_write_serial:
addi r15,r15,8 #r15 points to the code after the serial code
bne- cr7,_readcodes #lf code execution is false, skip serial code
lwz r5,-8(r15) #load TNNNZZZZ
lwz r11,-4(r15) #r11 = load VVVVVVVV
rlwinm r17,r5,0,16,31 #r17 = ZZZZ
rlwinm r10,r5,16,20,31 #r10 = NNN (# of times to write -1)
rlwinm r5,r5,4,28,31 #r5 = T (0:8bits/1:16bits/2:32bits)
_loop_serial:
cmpwi cr5,r5,1
beq- cr5,+16 #lf 16bits
bgt+ cr5,+20 #lf 32bits
bl _Write_08x
b +40
bl _Write_16x #write serial halfword (CT04,T=1)
b +32
lwzx r18, r9, r12
cmpw r4, r18
beq+ +20
stwx r4,r9,r12 #write serial word (CT04,T>=2)
icbi r9, r12 #Invalidate Icache around real memory offset
sync
isync
add r4,r4,r11 #value +=VVVVVVVV
add r9,r9,r17 #address +=ZZZZ
subic. r10,r10,1
bge+ _loop_serial #loop until all the data has been written
b _readcodes
#CT1=============================================================================
#32bits conditional (0,1,2,3): 20XXXXXX YYYYYYYY
#16bits conditional (4,5,6,7): 28XXXXXX ZZZZYYYY
#PS : 31 bit of address = endlf.
_conditional:
rlwinm. r9,r3,0,31,31 #r10 = (bit31 & 1) (endlf enabled?)
beq +16 #jump lf endlf is not enabled
rlwinm r8,r8,31,1,31 #Endlf (r8>>1)
andi. r9,r8,1 #r9=code execution status
cmpwi cr7,r9,0 #check code execution status in cr7
cmpwi cr5,r5,4 #compares sub code type and 4 in cr5
cmpwi cr3,r10,5 #compares code type and 5 in cr3
rlwimi r8,r8,1,0,30 #r8<<1 and current execution status = old execution status
bne- cr7,_true_end #lf code execution is set to false -> exit
bgt cr3,_addresscheck2 #lf code type==6 -> address check
add r12,r12,r3 #address = (ba/po)+(XXXXXX)
blt cr3,+12 #jump lf code type <5 (==1)
blt cr5,_condition_sub #compare [rN][rM]
b _conditional16_2 #counter compare
bge cr5,_conditional16 #lf sub code type>=4 -> 16 bits conditional
_conditional32:
rlwinm r12,r12,0,0,29 #32bits align
lwz r11,0(r12)
b _condition_sub
_conditional16:
rlwinm r12,r12,0,0,30 #16bits align
lhz r11,0(r12)
_conditional16_2:
nor r9,r4,r4
rlwinm r9,r9,16,16,31 #r9 = extract mask
and r11,r11,r9 #r11 &= r9
rlwinm r4,r4,0,16,31 #r4 = extract data to check against
_condition_sub:
cmpl cr6,r11,r4 #Unsigned compare. r11=data at address, r4=YYYYYYYY
andi. r9,r5,3
beq _skip_NE #lf sub code (type & 3) == 0
cmpwi r9,2
beq _skip_LE #lf sub code (type & 3) == 2
bgt _skip_GE #lf sub code (type & 3) == 3
_skip_EQ:#1
bne- cr6,_true_end #CT21, CT25, CT29 or CT2D (lf !=)
b _skip
_skip_NE:#0
beq- cr6,_true_end #CT20, CT24, CT28 or CT2C (lf==)
b _skip
_skip_LE:#2
bgt- cr6,_true_end #CT22, CT26, CT2A or CT2E (lf r4>[])
b _skip
_skip_GE:#3
blt- cr6,_true_end #CT23, CT27, CT2B or CT2F (lf r4<r4)
_skip:
ori r8,r8,1 #r8|=1 (execution status set to false)
_true_end:
bne+ cr3,_readcodes #lf code type <> 5
blt cr5,_readcodes
lwz r11,-8(r15) #load counter
bne cr7,_clearcounter #lf previous code execution false clear counter
andi. r12,r3,0x8 #else lf clear counter bit not set increase counter
beq _increase_counter
andi. r12,r8,0x1 #else lf.. code result true clear counter
beq _clearcounter
_increase_counter:
addi r12,r11,0x10 #else increase the counter
rlwimi r11,r12,0,12,27 #update counter
b _savecounter
_clearcounter:
rlwinm r11,r11,0,28,11 #clear the counter
_savecounter:
stw r11,-8(r15) #save counter
b _readcodes
#CT2============================================================================
#load base address (0): 40TYZ00N XXXXXXXX = (load/add:T) ba from [(ba/po:Y)+XXXXXXXX(+rN:Z)]
#set base address (1): 42TYZ00N XXXXXXXX = (set/add:T) ba to (ba/po:Y)+XXXXXXXX(+rN:Z)
#store base address (2): 440Y0000 XXXXXXXX = store base address to [(ba/po)+XXXXXXXX]
#set base address to (3): 4600XXXX 00000000 = set base address to code address+XXXXXXXX
#load pointer (4): 48TYZ00N XXXXXXXX = (load/add:T) po from [(ba/po:Y)+XXXXXXXX(+rN:Z)]
#set pointer (5): 4ATYZ00N XXXXXXXX = (set/add:T) po to (ba/po:Y)+XXXXXXXX(+rN:Y)
#store pointer (6): 4C0Y0000 XXXXXXXX = store pointer to [(ba/po)+XXXXXXXX]
#set pointer to (7): 4E00XXXX 00000000 = set pointer to code address+XXXXXXXX
_ba_pointer:
bne- cr7,_readcodes
rlwinm r9,r3,2,26,29 #r9 = extract N, makes N*4
rlwinm r14,r3,16,31,31 #r3 = add ba/po flag bit (Y)
cmpwi cr3,r14,0
cmpwi cr4,r5,4 #cr4 = compare sub code type with 4 (ba/po)
andi. r14,r5,3 #r14 = sub code type and 3
cmpwi cr5,r14,2 #compares sub code type and 2
blt- cr5,_p01
beq- cr5,_p2 #sub code type 2
_p3:
extsh r4,r3
add r4,r4,r15 #r4=XXXXXXXX+r15 (code location in memory)
b _pend
_p01:
rlwinm. r5,r3,20,31,31 #r3 = rN use bit (Z)
beq +12 #flag is not set(=0), address = XXXXXXXX
lwzx r9,r7,r9 #r9 = load register N
add r4,r4,r9 #flag is set (=1), address = XXXXXXXX+rN
beq cr3,+8 #(Y) flag is not set(=0), address = XXXXXXXX (+rN)
add r4,r12,r4 #address = XXXXXXXX (+rN) + (ba/po)
cmpwi cr5,r14,1
beq cr5,+8 #address = (ba/po)+XXXXXXXX(+rN)
lwz r4,0(r4) #address = [(ba/po)+XXXXXXXX(+rN)]
rlwinm. r3,r3,12,31,31 #r5 = add/replace flag (T)
beq _pend #flag is not set (=0), (ba/po)= XXXXXXXX (+rN) + (ba/po)
bge cr4,+12
add r4,r4,r6 #ba += XXXXXXXX (+rN) + (ba/po)
b _pend
add r4,r4,r16 #po += XXXXXXXX (+rN) + (ba/po)
b _pend
_p2:
rlwinm. r5,r3,20,31,31 #r3 = rN use bit (Z)
beq +12 #flag is not set(=0), address = XXXXXXXX
lwzx r9,r7,r9 #r9 = load register N
add r4,r4,r9 #flag is set (=1), address = XXXXXXXX+rN
bge cr4,+12
stwx r6,r12,r4 #[(ba/po)+XXXXXXXX] = base address
b _readcodes
stwx r16,r12,r4 #[(ba/po)+XXXXXXXX] = pointer
b _readcodes
_pend:
bge cr4,+12
mr r6,r4 #store result to base address
b _readcodes
mr r16,r4 #store result to pointer
b _readcodes
#CT3============================================================================
#set repeat (0): 6000ZZZZ 0000000P = set repeat
#execute repeat (1): 62000000 0000000P = execute repeat
#return (2): 64S00000 0000000P = return (lf true/false/always)
#goto (3): 66S0XXXX 00000000 = goto (lf true/false/always)
#gosub (4): 68S0XXXX 0000000P = gosub (lf true/false/always)
_repeat_goto:
rlwinm r9,r4,3,25,28 #r9 = extract P, makes P*8
addi r9,r9,0x40 #offset that points to block P's
cmpwi r5,2 #compares sub code type with 2
blt- _repeat
rlwinm. r11,r3,10,0,1 #extract (S&3)
beq +20 #S=0, skip lf true, don't skip lf false
bgt +8
b _b_bl_blr_nocheck #S=2/3, always skip (code exec status turned to true)
beq- cr7,_readcodes #S=1, skip lf false, don't skip lf true
b _b_bl_blr_nocheck
_b_bl_blr:
bne- cr7,_readcodes #lf code execution set to false skip code
_b_bl_blr_nocheck:
cmpwi r5,3
bgt- _bl #sub code type >=4, bl
beq+ _b #sub code type ==3, b
_blr:
lwzx r15,r7,r9 #loads the next code address
b _readcodes
_bl:
stwx r15,r7,r9 #stores the next code address in block P's address
_b:
extsh r4,r3 #XXXX becomes signed
rlwinm r4,r4,3,9,28
add r15,r15,r4 #next code address +/-=line XXXX
b _readcodes
_repeat:
bne- cr7,_readcodes #lf code execution set to false skip code
add r5,r7,r9 #r5 points to P address
bne- cr4,_execute_repeat #branch lf sub code type == 1
_set_repeat:
rlwinm r4,r3,0,16,31 #r4 = extract NNNNN
stw r15,0(r5) #store current code address to [bP's address]
stw r4,4(r5) #store NNNN to [bP's address+4]
b _readcodes
_execute_repeat:
lwz r9,4(r5) #load NNNN from [M+4]
cmpwi r9,0
beq- _readcodes
subi r9,r9,1
stw r9,4(r5) #saves (NNNN-1) to [bP's address+4]
lwz r15,0(r5) #load next code address from [bP's address]
b _readcodes
#CT4============================================================================
#set/add to rN(0) : 80SY000N XXXXXXXX = rN = (ba/po) + XXXXXXXX
#load rN (1) : 82UY000N XXXXXXXX = rN = [XXXXXXXX] (offset support) (U:8/16/32)
#store rN (2) : 84UYZZZN XXXXXXXX = store rN in [XXXXXXXX] (offset support) (8/16/32)
#operation 1 (3) : 86TY000N XXXXXXXX = operation rN?XXXXXXXX ([rN]?XXXXXXXX)
#operation 2 (4) : 88TY000N 0000000M = operation rN?rM ([rN]?rM, rN?[rM], [rN]?[rM])
#copy1 (5) : 8AYYYYNM XXXXXXXX = copy YYYY bytes from [rN] to ([rM]+)XXXXXXXX
#copy2 (6) : 8CYYYYNM XXXXXXXX = copy YYYY bytes from ([rN]+)XXXXXX to [rM]
#for copy1/copy2, lf register == 0xF, base address is used.
#of course, sub codes types 0/1, 2/3 and 4/5 can be put together lf we need more subtypes.
_operation_rN:
bne- cr7,_readcodes
rlwinm r11,r3,2,26,29 #r11 = extract N, makes N*4
add r26,r7,r11 #1st value address = rN's address
lwz r9,0(r26) #r9 = rN
rlwinm r14,r3,12,30,31 #extracts S, U, T (3bits)
beq- cr4,_op0 #lf sub code type = 0
cmpwi cr4,r5,5
bge- cr4,_op56 #lf sub code type = 5/6
cmpwi cr4,r5,3
bge- cr4,_op34 #lf sub code type = 3/4
cmpwi cr4,r5,1
_op12: #load/store
rlwinm. r5,r3,16,31,31 #+(ba/po) flag : Y
beq +8 #address = XXXXXXXX
add r4,r12,r4
cmpwi cr6,r14,1
bne- cr4,_store
_load:
bgt+ cr6,+24
beq- cr6,+12
lbz r4,0(r4) #load byte at address
b _store_reg
lhz r4,0(r4) #load halfword at address
b _store_reg
lwz r4,0(r4) #load word at address
b _store_reg
_store:
rlwinm r19,r3,28,20,31 #r9=r3 ror 12 (N84UYZZZ)
mr r12, r4
mr r4, r9
mr r5, r9
li r9, 0
_storeloop:
bgt+ cr6,+32
beq- cr6,+16
bl _Write_08x #store byte at address
addi r12,r12,1
b _storeloopend
bl _Write_16x #store byte at address
addi r12,r12,2
b _storeloopend
bl _Write_32
addi r12,r12,4
_storeloopend:
subic. r19,r19,1
bge _storeloop
b _readcodes
_op0:
rlwinm. r5,r3,16,31,31 #+(ba/po) flag : Y
beq +8 #value = XXXXXXXX
add r4,r4,r12 #value = XXXXXXXX+(ba/po)
andi. r5,r14,1 #add flag : S
beq _store_reg #add flag not set (=0), rN=value
add r4,r4,r9 #add flag set (=1), rN=rN+value
b _store_reg
_op34: #operation 1 & 2
rlwinm r10,r3,16,30,31 #extracts Y
rlwinm r14,r4,2,26,29 #r14 = extract M (in r4), makes M*=4
add r19,r7,r14 #2nd value address = rM's address
bne cr4,+8
subi r19,r15,4 #lf CT3, 2nd value address = XXXXXXXX's address
lwz r4,0(r26) #1st value = rN
lwz r9,0(r19) #2nd value = rM/XXXXXXXX
andi. r11,r10,1 #lf [] for 1st value
beq +8
mr r26,r4
andi. r11,r10,2 #lf [] for 2nd value
beq +16
mr r19,r9
bne+ cr4,+8
add r19,r12,r19 #lf CT3, 2nd value address = XXXXXXXX+(ba/op)
rlwinm. r5,r3,12,28,31 #operation # flag : T
cmpwi r5,9
bge _op_float
_operation_bl:
bl _operation_bl_return
_op450:
add r4,r9,r4 #N + M
b _store_reg
_op451:
mullw r4,r9,r4 #N * M
b _store_reg
_op452:
or r4,r9,r4 #N | M
b _store_reg
_op453:
and r4,r9,r4 #N & M
b _store_reg
_op454:
xor r4,r9,r4 #N ^ M
b _store_reg
_op455:
slw r4,r9,r4 #N << M
b _store_reg
_op456:
srw r4,r9,r4 #N >> M
b _store_reg
_op457:
rlwnm r4,r9,r4,0,31 #N rol M
b _store_reg
_op458:
sraw r4,r9,r4 #N asr M
_store_reg:
stw r4,0(r26) #Store result in rN/[rN]
b _readcodes
_op_float:
cmpwi r5,0xA
bgt _readcodes
lfs f2,0(r26) #f2 = load 1st value
lfs f3,0(r19) #f3 = load 2nd value
beq- _op45A
_op459:
fadds f2,f3,f2 #N = N + M (float)
b _store_float
_op45A:
fmuls f2,f3,f2 #N = N * M (float)
_store_float:
stfs f2,0(r26) #Store result in rN/[rN]
b _readcodes
_operation_bl_return:
mflr r10
rlwinm r5,r5,3,25,28 #r5 = T*8
add r10,r10,r5 #jumps to _op5: + r5
lwz r4,0(r26) #load [rN]
lwz r9,0(r19) #2nd value address = rM/XXXXXXXX
mtlr r10
blr
#copy1 (5) : 8AYYYYNM XXXXXXXX = copy YYYY bytes from [rN] to ([rM]+)XXXXXXXX
#copy2 (6) : 8CYYYYNM XXXXXXXX = copy YYYY bytes from ([rN]+)XXXXXX to [rM]
_op56:
bne- cr7,_readcodes #lf code execution set to false skip code
rlwinm r9,r3,24,0,31 #r9=r3 ror 8 (NM8AYYYY, NM8CYYYY)
mr r14,r12 #r14=(ba/po)
bl _load_NM
beq- cr4,+12
add r17,r17,r4 #lf sub code type==0 then source+=XXXXXXXX
b +8
add r9,r9,r4 #lf sub code type==1 then destination+=XXXXXXXX
rlwinm. r4,r3,24,16,31 #Extracts YYYY, compares it with 0
li r5,0
_copy_loop:
beq _readcodes #Loop until all bytes have been copied.
lbzx r10,r5,r17
stbx r10,r5,r9
addi r5,r5,1
cmpw r5,r4
b _copy_loop
#===============================================================================
#This is a routine called by _memory_copy and _compare_NM_16
_load_NM:
cmpwi cr5,r10,4 #compare code type and 4(rn Operations) in cr5
rlwinm r17,r9,6,26,29 #Extracts N*4
cmpwi r17,0x3C
lwzx r17,r7,r17 #Loads rN value in r17
bne +8
mr r17,r14 #lf N==0xF then source address=(ba/po)(+XXXXXXXX, CT5)
beq cr5,+8
lhz r17,0(r17) #...and lf CT5 then N = 16 bits at [XXXXXX+base address]
rlwinm r9,r9,10,26,29 #Extracts M*4
cmpwi r9,0x3C
lwzx r9,r7,r9 #Loads rM value in r9
bne +8
mr r9,r14 #lf M==0xF then dest address=(ba/po)(+XXXXXXXX, CT5)
beq cr5,+8
lhz r9,0(r9) #...and lf CT5 then M = 16 bits at [XXXXXX+base address]
blr
#CT5============================================================================
#16bits conditional (0,1,2,3): A0XXXXXX NM00YYYY (unknown values)
#16bits conditional (4,5,6,7): A8XXXXXX ZZZZYYYY (counter)
#sub codes types 0,1,2,3 compare [rN] with [rM] (both 16bits values)
#lf register == 0xF, the value at [base address+XXXXXXXX] is used.
_compare16_NM_counter:
cmpwi r5,4
bge _compare16_counter
_compare16_NM:
mr r9,r4 #r9=NM00YYYY
add r14,r3,r12 #r14 = XXXXXXXX+(ba/po)
rlwinm r14,r14,0,0,30 #16bits align (base address+XXXXXXXX)
bl _load_NM #r17 = N's value, r9 = M's value
nor r4,r4,r4 #r4=!r4
rlwinm r4,r4,0,16,31 #Extracts !YYYY
and r11,r9,r4 #r3 = (M AND !YYYY)
and r4,r17,r4 #r4 = (N AND !YYYY)
b _conditional
_compare16_counter:
rlwinm r11,r3,28,16,31 #extract counter value from r3 in r11
b _conditional
#===============================================================================
#execute (0) : C0000000 NNNNNNNN = execute. End with 4E800020 00000000.
#hook1 (2) : C4XXXXXX NNNNNNNN = insert instructions at XXXXXX. Same as C2.
#hook2 (3) : C6XXXXXX YYYYYYYY = branch from XXXXXX to YYYYYY
#on/off (6) : CC000000 00000000 = on/off switch
#range check (7) : CE000000 XXXXYYYY = is ba/po in XXXX0000-YYYY0000
_hook_execute:
mr r26,r4 #r26 = 0YYYYYYY
rlwinm r4,r4,3,0,28 #r4 = NNNNNNNN*8 = number of lines (and not number of bytes)
bne- cr4,_hook_addresscheck #lf sub code type != 0
bne- cr7,_skip_and_align
_execute:
mtlr r15
blrl
_skip_and_align:
add r15,r4,r15
addi r15,r15,7
rlwinm r15,r15,0,0,28 #align 64-bit
b _readcodes
_hook_addresscheck:
cmpwi cr4,r5,3
bgt- cr4,_addresscheck1 #lf sub code type ==6 or 7
lis r5,0x4800
add r12,r3,r12
rlwinm r12,r12,0,0,29 #align address
bne- cr4,_hook1 #lf sub code type ==2
_hook2:
bne- cr7,_readcodes
rlwinm r4,r26,0,0,29 #address &=0x01FFFFFC
sub r4,r4,r12 #r4 = to-from
rlwimi r5,r4,0,6,29 #r5 = (r4 AND 0x03FFFFFC) OR 0x48000000
rlwimi r5,r3,0,31,31 #restore lr bit
bl _Write_32
b _readcodes
_hook1:
bne- cr7,_skip_and_align
sub r9,r15,r12 #r9 = to-from
rlwimi r5,r9,0,6,29 #r5 = (r9 AND 0x03FFFFFC) OR 0x48000000
bl _Write_32
addi r12,r12,4
add r11,r15,r4
subi r11,r11,4 #r11 = address of the last word of the hook1 code
sub r9,r12,r11
rlwimi r5,r9,0,6,29 #r5 = (r9 AND 0x03FFFFFC) OR 0x48000000
mr r12, r11
bl _Write_32
b _skip_and_align
_addresscheck1:
cmpwi cr4,r5,6
beq cr4,_onoff
b _conditional
_addresscheck2:
rlwinm r12,r12,16,16,31
rlwinm r4,r26,16,16,31
rlwinm r26,r26,0,16,31
cmpw r12,r4
blt _skip
cmpw r12,r26
bge _skip
b _readcodes
_onoff:
rlwinm r5,r26,31,31,31 #extracts old exec status (x b a)
xori r5,r5,1
andi. r3,r8,1 #extracts current exec status
cmpw r5,r3
beq _onoff_end
rlwimi r26,r8,1,30,30
xori r26,r26,2
rlwinm. r5,r26,31,31,31 #extracts b
beq +8
xori r26,r26,1
stw r26,-4(r15) #updates the code value in the code list
_onoff_end:
rlwimi r8,r26,0,31,31 #current execution status = a
b _readcodes
#===============================================================================
#Full terminator (0) = E0000000 XXXXXXXX = full terminator
#Endlfs/Else (1) = E2T000VV XXXXXXXX = endlfs (+else)
#End code handler = F0000000 00000000
_terminator_onoff_:
cmpwi r11,0 #lf code type = 0xF
beq _notTerminator
cmpwi r5,1
beq _asmTypeba
cmpwi r5,2
beq _asmTypepo
cmpwi r5,3
beq _patchType
b _exitcodehandler
_asmTypeba:
rlwinm r12,r6,0,0,6 # use base address
_asmTypepo:
rlwinm r23,r4,8,24,31 # extract number of half words to XOR
rlwinm r24,r4,24,16,31 # extract XOR checksum
rlwinm r4,r4,0,24,31 # set code value to number of ASM lines only
bne cr7,_goBackToHandler #skip code if code execution is set to false
rlwinm. r25,r23,0,24,24 # check for negative number of half words
mr r26,r12 # copy ba/po address
add r26,r3,r26 # add code offset to ba/po code address
rlwinm r26,r26,0,0,29 # clear last two bits to align address to 32-bit
beq _positiveOffset # if number of half words is negative, extra setup needs to be done
extsb r23,r23
neg r23,r23
mulli r25,r23,2
addi r25,r25,4
subf r26,r25,r26
_positiveOffset:
cmpwi r23,0
beq _endXORLoop
li r25,0
mtctr r23
_XORLoop:
lhz r27,4(r26)
xor r25,r27,r25
addi r26,r26,2
bdnz _XORLoop
_endXORLoop:
cmpw r24,r25
bne _goBackToHandler
b _hook_execute
_patchType:
rlwimi r8,r8,1,0,30 #r8<<1 and current execution status = old execution status
bne cr7,_exitpatch #lf code execution is set to false -> exit
rlwinm. r23,r3,22,0,1
bgt _patchfail
blt _copytopo
_runpatch:
rlwinm r30,r3,0,24,31
mulli r30,r30,2
rlwinm r23,r4,0,0,15
xoris r24,r23,0x8000
cmpwi r24,0
bne- _notincodehandler
ori r23,r23,0x3000
_notincodehandler:
rlwinm r24,r4,16,0,15
mulli r25,r30,4
subf r24,r25,r24
_patchloop:
li r25,0
_patchloopnext:
mulli r26,r25,4
lwzx r27,r15,r26
lwzx r26,r23,r26
addi r25,r25,1
cmplw r23,r24
bgt _failpatchloop
cmpw r25,r30
bgt _foundaddress
cmpw r26,r27
beq _patchloopnext
addi r23,r23,4
b _patchloop
_foundaddress:
lwz r3,-8(r15)
ori r3,r3,0x300
stw r3,-8(r15)
stw r23,-4(r15)
mr r16,r23
b _exitpatch
_failpatchloop:
lwz r3,-8(r15)
ori r3,r3,0x100
stw r3,-8(r15)
_patchfail:
ori r8,r8,1 #r8|=1 (execution status set to false)
b _exitpatch
_copytopo:
mr r16,r4
_exitpatch:
rlwinm r4,r3,0,24,31 # set code to number of lines only
_goBackToHandler:
mulli r4,r4,8
add r15,r4,r15 # skip the lines of the code
b _readcodes
_notTerminator:
_terminator:
bne cr4,+12 #check lf sub code type == 0
li r8,0 #clear whole code execution status lf T=0
b +20
rlwinm. r9,r3,0,27,31 #extract VV
# bne +8 #lf VV!=0
# bne- cr7,+16
rlwinm r5,r3,12,31,31 #extract "else" bit
srw r8,r8,r9 #r8>>VV, meaning endlf VV lfs
rlwinm. r23,r8,31,31,31
bne +8 # execution is false if code execution >>, so don't invert code status
xor r8,r8,r5 #lf 'else' is set then invert current code status
_load_baseaddress:
rlwinm. r5,r4,0,0,15
beq +8
mr r6,r5 #base address = r4
rlwinm. r5,r4,16,0,15
beq +8
mr r16,r5 #pointer = r4
b _readcodes
#===============================================================================
frozenvalue: #frozen value, then LR
.long 0,0
dwordbuffer:
.long 0,0
rem:
.long 0
bpbuffer:
.long 0 #int address to bp on
.long 0 #data address to bp on
.long 0 #alignement check
.long 0 #counter for alignement
regbuffer:
.space 72*4
.align 3
codelist:
.space 2*4
.end
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