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t16.decode (9606B)


      1 # Thumb1 instructions
      2 #
      3 #  Copyright (c) 2019 Linaro, Ltd
      4 #
      5 # This library is free software; you can redistribute it and/or
      6 # modify it under the terms of the GNU Lesser General Public
      7 # License as published by the Free Software Foundation; either
      8 # version 2.1 of the License, or (at your option) any later version.
      9 #
     10 # This library is distributed in the hope that it will be useful,
     11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
     12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13 # Lesser General Public License for more details.
     14 #
     15 # You should have received a copy of the GNU Lesser General Public
     16 # License along with this library; if not, see <http://www.gnu.org/licenses/>.
     17 
     18 #
     19 # This file is processed by scripts/decodetree.py
     20 #
     21 
     22 &empty           !extern
     23 &s_rrr_shi       !extern s rd rn rm shim shty
     24 &s_rrr_shr       !extern s rn rd rm rs shty
     25 &s_rri_rot       !extern s rn rd imm rot
     26 &s_rrrr          !extern s rd rn rm ra
     27 &rrr_rot         !extern rd rn rm rot
     28 &rr              !extern rd rm
     29 &ri              !extern rd imm
     30 &r               !extern rm
     31 &i               !extern imm
     32 &ldst_rr         !extern p w u rn rt rm shimm shtype
     33 &ldst_ri         !extern p w u rn rt imm
     34 &ldst_block      !extern rn i b u w list
     35 &setend          !extern E
     36 &cps             !extern mode imod M A I F
     37 &ci              !extern cond imm
     38 
     39 # Set S if the instruction is outside of an IT block.
     40 %s               !function=t16_setflags
     41 
     42 # Data-processing (two low registers)
     43 
     44 %reg_0           0:3
     45 
     46 @lll_noshr       ...... .... rm:3 rd:3 \
     47                  &s_rrr_shi %s rn=%reg_0 shim=0 shty=0
     48 @xll_noshr       ...... .... rm:3 rn:3 \
     49                  &s_rrr_shi s=1 rd=0 shim=0 shty=0
     50 @lxl_shr         ...... .... rs:3 rd:3 \
     51                  &s_rrr_shr %s rm=%reg_0 rn=0
     52 
     53 AND_rrri         010000 0000 ... ...            @lll_noshr
     54 EOR_rrri         010000 0001 ... ...            @lll_noshr
     55 MOV_rxrr         010000 0010 ... ...            @lxl_shr shty=0  # LSL
     56 MOV_rxrr         010000 0011 ... ...            @lxl_shr shty=1  # LSR
     57 MOV_rxrr         010000 0100 ... ...            @lxl_shr shty=2  # ASR
     58 ADC_rrri         010000 0101 ... ...            @lll_noshr
     59 SBC_rrri         010000 0110 ... ...            @lll_noshr
     60 MOV_rxrr         010000 0111 ... ...            @lxl_shr shty=3  # ROR
     61 TST_xrri         010000 1000 ... ...            @xll_noshr
     62 RSB_rri          010000 1001 rn:3 rd:3          &s_rri_rot %s imm=0 rot=0
     63 CMP_xrri         010000 1010 ... ...            @xll_noshr
     64 CMN_xrri         010000 1011 ... ...            @xll_noshr
     65 ORR_rrri         010000 1100 ... ...            @lll_noshr
     66 MUL              010000 1101 rn:3 rd:3          &s_rrrr %s rm=%reg_0 ra=0
     67 BIC_rrri         010000 1110 ... ...            @lll_noshr
     68 MVN_rxri         010000 1111 ... ...            @lll_noshr
     69 
     70 # Load/store (register offset)
     71 
     72 @ldst_rr         ....... rm:3 rn:3 rt:3 \
     73                  &ldst_rr p=1 w=0 u=1 shimm=0 shtype=0
     74 
     75 STR_rr           0101 000 ... ... ...           @ldst_rr
     76 STRH_rr          0101 001 ... ... ...           @ldst_rr
     77 STRB_rr          0101 010 ... ... ...           @ldst_rr
     78 LDRSB_rr         0101 011 ... ... ...           @ldst_rr
     79 LDR_rr           0101 100 ... ... ...           @ldst_rr
     80 LDRH_rr          0101 101 ... ... ...           @ldst_rr
     81 LDRB_rr          0101 110 ... ... ...           @ldst_rr
     82 LDRSH_rr         0101 111 ... ... ...           @ldst_rr
     83 
     84 # Load/store word/byte (immediate offset)
     85 
     86 %imm5_6x4       6:5 !function=times_4
     87 
     88 @ldst_ri_1      ..... imm:5 rn:3 rt:3 \
     89                 &ldst_ri p=1 w=0 u=1
     90 @ldst_ri_4      ..... ..... rn:3 rt:3 \
     91                 &ldst_ri p=1 w=0 u=1 imm=%imm5_6x4
     92 
     93 STR_ri          01100 ..... ... ...             @ldst_ri_4
     94 LDR_ri          01101 ..... ... ...             @ldst_ri_4
     95 STRB_ri         01110 ..... ... ...             @ldst_ri_1
     96 LDRB_ri         01111 ..... ... ...             @ldst_ri_1
     97 
     98 # Load/store halfword (immediate offset)
     99 
    100 %imm5_6x2       6:5 !function=times_2
    101 @ldst_ri_2      ..... ..... rn:3 rt:3 \
    102                 &ldst_ri p=1 w=0 u=1 imm=%imm5_6x2
    103 
    104 STRH_ri         10000 ..... ... ...             @ldst_ri_2
    105 LDRH_ri         10001 ..... ... ...             @ldst_ri_2
    106 
    107 # Load/store (SP-relative)
    108 
    109 %imm8_0x4       0:8 !function=times_4
    110 @ldst_spec_i    ..... rt:3 ........ \
    111                 &ldst_ri p=1 w=0 u=1 imm=%imm8_0x4
    112 
    113 STR_ri          10010 ... ........              @ldst_spec_i rn=13
    114 LDR_ri          10011 ... ........              @ldst_spec_i rn=13
    115 
    116 # Load (PC-relative)
    117 
    118 LDR_ri          01001 ... ........              @ldst_spec_i rn=15
    119 
    120 # Add PC/SP (immediate)
    121 
    122 ADR             10100 rd:3 ........             imm=%imm8_0x4
    123 ADD_rri         10101 rd:3 ........ \
    124                 &s_rri_rot rn=13 s=0 rot=0 imm=%imm8_0x4  # SP
    125 
    126 # Load/store multiple
    127 
    128 @ldstm          ..... rn:3 list:8               &ldst_block i=1 b=0 u=0 w=1
    129 
    130 STM             11000 ... ........              @ldstm
    131 LDM_t16         11001 ... ........              @ldstm
    132 
    133 # Shift (immediate)
    134 
    135 @shift_i        ..... shim:5 rm:3 rd:3          &s_rrr_shi %s rn=%reg_0
    136 
    137 MOV_rxri        000 00 ..... ... ...            @shift_i shty=0  # LSL
    138 MOV_rxri        000 01 ..... ... ...            @shift_i shty=1  # LSR
    139 MOV_rxri        000 10 ..... ... ...            @shift_i shty=2  # ASR
    140 
    141 # Add/subtract (three low registers)
    142 
    143 @addsub_3       ....... rm:3 rn:3 rd:3 \
    144                 &s_rrr_shi %s shim=0 shty=0
    145 
    146 ADD_rrri        0001100 ... ... ...             @addsub_3
    147 SUB_rrri        0001101 ... ... ...             @addsub_3
    148 
    149 # Add/subtract (two low registers and immediate)
    150 
    151 @addsub_2i      ....... imm:3 rn:3 rd:3 \
    152                 &s_rri_rot %s rot=0
    153 
    154 ADD_rri         0001 110 ... ... ...            @addsub_2i
    155 SUB_rri         0001 111 ... ... ...            @addsub_2i
    156 
    157 # Add, subtract, compare, move (one low register and immediate)
    158 
    159 %reg_8          8:3
    160 @arith_1i       ..... rd:3 imm:8 \
    161                 &s_rri_rot rot=0 rn=%reg_8
    162 
    163 MOV_rxi         00100 ... ........              @arith_1i %s
    164 CMP_xri         00101 ... ........              @arith_1i s=1
    165 ADD_rri         00110 ... ........              @arith_1i %s
    166 SUB_rri         00111 ... ........              @arith_1i %s
    167 
    168 # Add, compare, move (two high registers)
    169 
    170 %reg_0_7        7:1 0:3
    171 @addsub_2h      .... .... . rm:4 ... \
    172                 &s_rrr_shi rd=%reg_0_7 rn=%reg_0_7 shim=0 shty=0
    173 
    174 ADD_rrri        0100 0100 . .... ...            @addsub_2h s=0
    175 CMP_xrri        0100 0101 . .... ...            @addsub_2h s=1
    176 MOV_rxri        0100 0110 . .... ...            @addsub_2h s=0
    177 
    178 # Adjust SP (immediate)
    179 
    180 %imm7_0x4       0:7 !function=times_4
    181 @addsub_sp_i    .... .... . ....... \
    182                 &s_rri_rot s=0 rd=13 rn=13 rot=0 imm=%imm7_0x4
    183 
    184 ADD_rri         1011 0000 0 .......             @addsub_sp_i
    185 SUB_rri         1011 0000 1 .......             @addsub_sp_i
    186 
    187 # Branch and exchange
    188 
    189 @branchr        .... .... . rm:4 ...            &r
    190 
    191 BX              0100 0111 0 .... 000            @branchr
    192 BLX_r           0100 0111 1 .... 000            @branchr
    193 BXNS            0100 0111 0 .... 100            @branchr
    194 BLXNS           0100 0111 1 .... 100            @branchr
    195 
    196 # Extend
    197 
    198 @extend         .... .... .. rm:3 rd:3          &rrr_rot rn=15 rot=0
    199 
    200 SXTAH           1011 0010 00 ... ...            @extend
    201 SXTAB           1011 0010 01 ... ...            @extend
    202 UXTAH           1011 0010 10 ... ...            @extend
    203 UXTAB           1011 0010 11 ... ...            @extend
    204 
    205 # Change processor state
    206 
    207 %imod           4:1 !function=plus_2
    208 
    209 SETEND          1011 0110 010 1 E:1 000         &setend
    210 {
    211   CPS           1011 0110 011 . 0 A:1 I:1 F:1   &cps mode=0 M=0 %imod
    212   CPS_v7m       1011 0110 011 im:1 00 I:1 F:1
    213 }
    214 
    215 # Reverse bytes
    216 
    217 @rdm            .... .... .. rm:3 rd:3          &rr
    218 
    219 REV             1011 1010 00 ... ...            @rdm
    220 REV16           1011 1010 01 ... ...            @rdm
    221 REVSH           1011 1010 11 ... ...            @rdm
    222 
    223 # Hints
    224 
    225 {
    226   {
    227     YIELD       1011 1111 0001 0000
    228     WFE         1011 1111 0010 0000
    229     WFI         1011 1111 0011 0000
    230 
    231     # TODO: Implement SEV, SEVL; may help SMP performance.
    232     # SEV       1011 1111 0100 0000
    233     # SEVL      1011 1111 0101 0000
    234 
    235     # The canonical nop has the second nibble as 0000, but the whole of the
    236     # rest of the space is a reserved hint, behaves as nop.
    237     NOP         1011 1111 ---- 0000
    238   }
    239   IT            1011 1111 cond_mask:8
    240 }
    241 
    242 # Miscellaneous 16-bit instructions
    243 
    244 %imm6_9_3       9:1 3:5 !function=times_2
    245 
    246 HLT             1011 1010 10 imm:6              &i
    247 BKPT            1011 1110 imm:8                 &i
    248 CBZ             1011 nz:1 0.1 ..... rn:3        imm=%imm6_9_3
    249 
    250 # Push and Pop
    251 
    252 %push_list      0:9 !function=t16_push_list
    253 %pop_list       0:9 !function=t16_pop_list
    254 
    255 STM             1011 010 ......... \
    256                 &ldst_block i=0 b=1 u=0 w=1 rn=13 list=%push_list
    257 LDM_t16         1011 110 ......... \
    258                 &ldst_block i=1 b=0 u=0 w=1 rn=13 list=%pop_list
    259 
    260 # Conditional branches, Supervisor call
    261 
    262 %imm8_0x2       0:s8 !function=times_2
    263 
    264 {
    265   UDF           1101 1110 ---- ----
    266   SVC           1101 1111 imm:8                 &i
    267   B_cond_thumb  1101 cond:4 ........            &ci imm=%imm8_0x2
    268 }
    269 
    270 # Unconditional Branch
    271 
    272 %imm11_0x2      0:s11 !function=times_2
    273 
    274 B               11100 ...........               &i imm=%imm11_0x2
    275 
    276 # thumb_insn_is_16bit() ensures we won't be decoding these as
    277 # T16 instructions for a Thumb2 CPU, so these patterns must be
    278 # a Thumb1 split BL/BLX.
    279 BLX_suffix      11101 imm:11                    &i
    280 BL_BLX_prefix   11110 imm:s11                   &i
    281 BL_suffix       11111 imm:11                    &i