Annotation of gforth/arch/mips/disasm.fs, revision 1.8

1.1       anton       1: \ disasm.fs    disassembler file (for MIPS R3000)
                      2: \
                      3: \ Copyright (C) 1995-97 Martin Anton Ertl, Christian Pirker
                      4: \
                      5: \ This file is part of RAFTS.
                      6: \
                      7: \      RAFTS is free software; you can redistribute it and/or
                      8: \      modify it under the terms of the GNU General Public License
                      9: \      as published by the Free Software Foundation; either version 2
                     10: \      of the License, or (at your option) any later version.
                     11: \
                     12: \      This program is distributed in the hope that it will be useful,
                     13: \      but WITHOUT ANY WARRANTY; without even the implied warranty of
                     14: \      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     15: \      GNU General Public License for more details.
                     16: \
                     17: \      You should have received a copy of the GNU General Public License
                     18: \      along with this program; if not, write to the Free Software
                     19: \      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
                     20: 
1.4       anton      21: \ this disassembler is based on data from the R4400 manual
                     22: \ http://www.mips.com/Documentation/R4400_Uman_book_Ed2.pdf, in
1.6       anton      23: \ particular pages A3, A181, A182 (p. 471, 649, 650 in xpdf).
1.4       anton      24: \ it is limited to the R3000 (MIPS-I) architecture, though.
1.2       anton      25: 
1.7       anton      26: \ test this with
                     27: \ gforth arch/mips/disasm.fs -e "here" arch/mips/testdisasm.fs -e "here over - disasm-dump bye" |sed 's/([^)]*) //'|diff -u - arch/mips/testasm.fs
                     28: 
1.8     ! anton      29: get-current
        !            30: vocabulary disassembler
        !            31: also disassembler definitions
        !            32: 
1.4       anton      33: \ instruction fields
1.3       anton      34: 
                     35: : disasm-op ( w -- u )
                     36:     26 rshift ;
                     37: 
                     38: : disasm-rs ( w -- u )
                     39:     21 rshift $1F and ;
                     40: 
                     41: : disasm-rt ( w -- u )
                     42:     16 rshift $1f and ;
                     43: 
                     44: : disasm-rd ( w -- u )
                     45:     11 rshift $1f and ;
                     46: 
                     47: : disasm-shamt ( w -- u )
                     48:     \ shift amount field
                     49:     6 rshift $1f and ;
                     50: 
                     51: : disasm-funct ( w -- u )
                     52:     $3f and ;
                     53: 
                     54: : disasm-copz ( w -- u )
                     55:     disasm-op 3 and ;
                     56: 
1.5       anton      57: : disasm-uimm ( w -- u )
                     58:     $ffff and ;
                     59: 
1.3       anton      60: : disasm-imm ( w -- n )
1.5       anton      61:     disasm-uimm dup 15 rshift negate 15 lshift or ;
1.3       anton      62: 
                     63: : disasm-relative ( addr n -- w )
                     64:     \ compute printable form of relative address n relative to addr
1.6       anton      65:     2 lshift nip ( + ) ;
1.3       anton      66: 
1.4       anton      67: \ decode tables
                     68: 
                     69: : disasm-illegal ( addr w -- )
                     70:     \ disassemble illegal/unknown instruction w at addr
                     71:     hex. ." , ( illegal inst ) " drop ;
                     72: 
                     73: : disasm-table ( n "name" -- )
                     74:     \ initialize table with n entries with disasm-illegal
                     75:     create 0 ?do
                     76:        ['] disasm-illegal ,
                     77:     loop
                     78: does> ( u -- addr )
                     79:     swap cells + ;
                     80: 
                     81: $40 disasm-table opc-tab-entry     \ top-level decode table
                     82: $40 disasm-table funct-tab-entry   \ special function table
                     83: $20 disasm-table regimm-tab-entry  \ regim instructions rt table
                     84: $20 disasm-table copz-rs-tab-entry \ COPz instructions rs table
                     85: $20 disasm-table copz-rt-tab-entry \ COPz BC instructions rt table
                     86: $40 disasm-table cp0-tab-entry     \ COP0 CO instructions funct table
                     87: 
1.3       anton      88: \ disassembler central decode cascade
                     89: 
1.8     ! anton      90: dup set-current
        !            91: 
1.3       anton      92: : disasm-inst ( addr w -- )
                     93:     \G disassemble instruction w at addr (addr is used for computing
                     94:     \G branch targets)
1.4       anton      95:     dup disasm-op opc-tab-entry @ execute ;
1.3       anton      96: 
                     97: : disasm-dump ( addr u -- ) \ gforth
                     98:     \G disassemble u aus starting at addr
                     99:     bounds u+do
                    100:        cr ." ( " i hex. ." ) " i i @ disasm-inst
                    101:        1 cells +loop ;
                    102: 
1.8     ! anton     103: definitions
        !           104: 
1.3       anton     105: : disasm-special ( addr w -- )
                    106:     \ disassemble inst with opcode special
1.4       anton     107:     dup disasm-funct funct-tab-entry @ execute ;
                    108: ' disasm-special 0 opc-tab-entry ! \ enter it for opcode special
1.3       anton     109: 
                    110: : disasm-regimm ( addr w -- )
                    111:     \ disassemble regimm inst
1.4       anton     112:     dup disasm-rt regimm-tab-entry @ execute ;
                    113: ' disasm-regimm 1 opc-tab-entry ! \ enter it for opcode regimm
1.3       anton     114: 
                    115: : disasm-copz-rs ( addr w -- )
                    116:     \ disassemble inst with opcode COPz
1.4       anton     117:     dup disasm-rs copz-rs-tab-entry @ execute ;
                    118: ' disasm-copz-rs $10 opc-tab-entry ! \ enter it for opcodes COPz
                    119: ' disasm-copz-rs $11 opc-tab-entry !
                    120: ' disasm-copz-rs $12 opc-tab-entry !
1.3       anton     121: 
                    122: : disasm-copz-rt ( addr w -- )
                    123:     \ disassemble inst with opcode COPz, rs=BC
1.4       anton     124:     dup disasm-rt copz-rt-tab-entry @ execute ;
                    125: ' disasm-copz-rt $08 copz-rs-tab-entry ! \ into COPz-table for rs=BC
1.3       anton     126: 
                    127: : disasm-cp0 ( addr w -- )
                    128:     \ disassemble inst with opcode COPz, rs=CO
1.4       anton     129:     dup disasm-funct cp0-tab-entry @ execute ;
                    130: ' disasm-cp0 $10 copz-rs-tab-entry ! \ into COPz-table for rs=CO
1.3       anton     131: 
1.4       anton     132: \ dummy words for insts.fs (words with these names are needed by asm.fs)
1.3       anton     133: 
                    134: : asm-op ( -- ) ;
1.4       anton     135: : asm-rs ( -- ) ;
                    136: : asm-rt ( -- ) ;
                    137: 
                    138: \ disassemble various formats
1.3       anton     139: 
                    140: : disasm-J-target ( addr w -- )
                    141:     \ print jump target
1.7       anton     142:     2 lshift $0fffffff and swap $f0000000 and or hex. ;
1.3       anton     143: 
                    144: : disasm-I-rs,rt,imm ( addr w -- )
                    145:     dup disasm-rs .
                    146:     dup disasm-rt .
                    147:     disasm-imm disasm-relative . ;
                    148: 
                    149: : disasm-I-rs,imm ( addr w -- )
                    150:     dup disasm-rs .
                    151:     disasm-imm disasm-relative . ;
                    152: 
                    153: : disasm-rt,rs,imm ( addr w -- )
                    154:     dup disasm-rt .
                    155:     dup disasm-rs .
                    156:     disasm-imm .
                    157:     drop ;
1.1       anton     158: 
1.5       anton     159: : disasm-rt,rs,uimm ( addr w -- )
1.3       anton     160:     dup disasm-rt .
1.5       anton     161:     dup disasm-rs .
                    162:     disasm-uimm hex.
                    163:     drop ;
                    164: 
                    165: : disasm-rt,uimm ( addr w -- )
                    166:     dup disasm-rt .
                    167:     disasm-uimm hex.
1.1       anton     168:     drop ;
                    169: 
1.3       anton     170: : disasm-rt,imm,rs ( addr w -- )
                    171:     dup disasm-rt .
                    172:     dup disasm-imm .
                    173:     dup disasm-rs .
                    174:     2drop ;
                    175: 
                    176: : disasm-rd,rt,sa ( addr w -- )
                    177:     dup disasm-rd .
                    178:     dup disasm-rt .
                    179:     dup disasm-shamt .
                    180:     2drop ;
                    181: 
                    182: : disasm-rd,rt,rs ( addr w -- )
                    183:     dup disasm-rd .
                    184:     dup disasm-rt .
                    185:     dup disasm-rs .
                    186:     2drop ;
                    187: 
                    188: : disasm-rs. ( addr w -- )
                    189:     dup disasm-rs .
                    190:     2drop ;
                    191: 
                    192: : disasm-rd,rs ( addr w -- )
                    193:     dup disasm-rd .
                    194:     dup disasm-rs .
                    195:     2drop ;
                    196: 
                    197: : disasm-rd. ( addr w -- )
                    198:     dup disasm-rd .
                    199:     2drop ;
                    200: 
                    201: : disasm-rs,rt ( addr w -- )
                    202:     dup disasm-rs .
                    203:     dup disasm-rt .
                    204:     2drop ;
                    205: 
                    206: : disasm-rd,rs,rt ( addr w -- )
                    207:     dup disasm-rd .
                    208:     dup disasm-rs .
                    209:     dup disasm-rt .
                    210:     2drop ;
                    211: 
                    212: : disasm-rt,rd,z ( addr w -- )
                    213:     dup disasm-rt .
                    214:     dup disasm-rd .
                    215:     dup disasm-copz .
                    216:     2drop ;
                    217: 
1.5       anton     218: : disasm-I-imm,z ( addr w -- )
                    219:     tuck disasm-imm disasm-relative .
                    220:     disasm-copz . ;
1.4       anton     221: 
                    222: \ meta-defining word for instruction format disassembling definitions
                    223: 
                    224: \ The following word defines instruction-format words, which in turn
                    225: \ define anonymous words for disassembling specific instructions and
                    226: \ put them in the appropriate decode table.
                    227: 
                    228: : define-format ( disasm-xt table-xt -- )
                    229:     \ define an instruction format that uses disasm-xt for
                    230:     \ disassembling and enters the defined instructions into table
                    231:     \ table-xt
                    232:     create 2,
                    233: does> ( u "inst" -- )
                    234:     \ defines an anonymous word for disassembling instruction inst,
                    235:     \ and enters it as u-th entry into table-xt
                    236:     2@ swap here name string, ( u table-xt disasm-xt c-addr ) \ remember string
                    237:     noname create 2,      \ define anonymous word
                    238:     execute lastxt swap ! \ enter xt of defined word into table-xt
                    239: does> ( addr w -- )
                    240:     \ disassemble instruction w at addr
                    241:     2@ >r ( addr w disasm-xt R: c-addr )
                    242:     execute ( R: c-addr ) \ disassemble operands
                    243:     r> count type ; \ print name 
                    244: 
                    245: \ all the following words have the stack effect ( u "name" )
                    246: ' disasm-J-target    ' opc-tab-entry    define-format asm-J-target
                    247: ' disasm-I-rs,rt,imm ' opc-tab-entry    define-format asm-I-rs,rt,imm
                    248: ' disasm-I-rs,imm    ' opc-tab-entry    define-format asm-I-rs,imm1
                    249: ' disasm-rt,rs,imm   ' opc-tab-entry    define-format asm-I-rt,rs,imm
1.5       anton     250: ' disasm-rt,rs,uimm   ' opc-tab-entry   define-format asm-I-rt,rs,uimm
                    251: ' disasm-rt,uimm      ' opc-tab-entry   define-format asm-I-rt,uimm
1.4       anton     252: ' disasm-rt,imm,rs   ' opc-tab-entry    define-format asm-I-rt,offset,rs
                    253: ' disasm-rd,rt,sa    ' funct-tab-entry          define-format asm-special-rd,rt,sa
                    254: ' disasm-rd,rt,rs    ' funct-tab-entry          define-format asm-special-rd,rt,rs
                    255: ' disasm-rs.         ' funct-tab-entry          define-format asm-special-rs
                    256: ' disasm-rd,rs       ' funct-tab-entry          define-format asm-special-rd,rs
                    257: ' 2drop              ' funct-tab-entry          define-format asm-special-nothing
                    258: ' disasm-rd.         ' funct-tab-entry          define-format asm-special-rd
                    259: ' disasm-rs,rt       ' funct-tab-entry          define-format asm-special-rs,rt
                    260: ' disasm-rd,rs,rt    ' funct-tab-entry          define-format asm-special-rd,rs,rt
                    261: ' disasm-I-rs,imm    ' regimm-tab-entry  define-format asm-regimm-rs,imm
                    262: ' 2drop              ' cp0-tab-entry     define-format asm-copz0
                    263: ' disasm-rt,rd,z     ' copz-rs-tab-entry define-format asm-copz-rt,rd1
1.5       anton     264: ' disasm-I-imm,z     ' copz-rt-tab-entry define-format asm-copz-imm1
1.4       anton     265: 
                    266: : asm-I-rs,imm ( u1 u2 "name" -- ; compiled code: addr w -- )
                    267:     nip asm-I-rs,imm1 ;
                    268: 
1.3       anton     269: : asm-copz-rt,rd ( u1 u2 "name" -- )
1.4       anton     270:     drop asm-copz-rt,rd1 ;
1.3       anton     271: 
1.4       anton     272: : asm-copz-rt,offset,rs ( u "name" -- )
                    273:     \ ignore these insts, we disassemble using  asm-I-rt,offset,rs
                    274:     drop name 2drop ;
1.3       anton     275: 
                    276: : asm-copz-imm ( u1 u2 u3 "name" -- )
1.4       anton     277:     drop nip asm-copz-imm1 ;
1.1       anton     278: 
1.3       anton     279: include ./insts.fs
1.8     ! anton     280: 
        !           281: previous set-current

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