qemu/target/arm/t16.decode
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   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
  53AND_rrri         010000 0000 ... ...            @lll_noshr
  54EOR_rrri         010000 0001 ... ...            @lll_noshr
  55MOV_rxrr         010000 0010 ... ...            @lxl_shr shty=0  # LSL
  56MOV_rxrr         010000 0011 ... ...            @lxl_shr shty=1  # LSR
  57MOV_rxrr         010000 0100 ... ...            @lxl_shr shty=2  # ASR
  58ADC_rrri         010000 0101 ... ...            @lll_noshr
  59SBC_rrri         010000 0110 ... ...            @lll_noshr
  60MOV_rxrr         010000 0111 ... ...            @lxl_shr shty=3  # ROR
  61TST_xrri         010000 1000 ... ...            @xll_noshr
  62RSB_rri          010000 1001 rn:3 rd:3          &s_rri_rot %s imm=0 rot=0
  63CMP_xrri         010000 1010 ... ...            @xll_noshr
  64CMN_xrri         010000 1011 ... ...            @xll_noshr
  65ORR_rrri         010000 1100 ... ...            @lll_noshr
  66MUL              010000 1101 rn:3 rd:3          &s_rrrr %s rm=%reg_0 ra=0
  67BIC_rrri         010000 1110 ... ...            @lll_noshr
  68MVN_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
  75STR_rr           0101 000 ... ... ...           @ldst_rr
  76STRH_rr          0101 001 ... ... ...           @ldst_rr
  77STRB_rr          0101 010 ... ... ...           @ldst_rr
  78LDRSB_rr         0101 011 ... ... ...           @ldst_rr
  79LDR_rr           0101 100 ... ... ...           @ldst_rr
  80LDRH_rr          0101 101 ... ... ...           @ldst_rr
  81LDRB_rr          0101 110 ... ... ...           @ldst_rr
  82LDRSH_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
  93STR_ri          01100 ..... ... ...             @ldst_ri_4
  94LDR_ri          01101 ..... ... ...             @ldst_ri_4
  95STRB_ri         01110 ..... ... ...             @ldst_ri_1
  96LDRB_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
 104STRH_ri         10000 ..... ... ...             @ldst_ri_2
 105LDRH_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
 113STR_ri          10010 ... ........              @ldst_spec_i rn=13
 114LDR_ri          10011 ... ........              @ldst_spec_i rn=13
 115
 116# Load (PC-relative)
 117
 118LDR_ri          01001 ... ........              @ldst_spec_i rn=15
 119
 120# Add PC/SP (immediate)
 121
 122ADR             10100 rd:3 ........             imm=%imm8_0x4
 123ADD_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
 130STM             11000 ... ........              @ldstm
 131LDM_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
 137MOV_rxri        000 00 ..... ... ...            @shift_i shty=0  # LSL
 138MOV_rxri        000 01 ..... ... ...            @shift_i shty=1  # LSR
 139MOV_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
 146ADD_rrri        0001100 ... ... ...             @addsub_3
 147SUB_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
 154ADD_rri         0001 110 ... ... ...            @addsub_2i
 155SUB_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
 163MOV_rxi         00100 ... ........              @arith_1i %s
 164CMP_xri         00101 ... ........              @arith_1i s=1
 165ADD_rri         00110 ... ........              @arith_1i %s
 166SUB_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
 174ADD_rrri        0100 0100 . .... ...            @addsub_2h s=0
 175CMP_xrri        0100 0101 . .... ...            @addsub_2h s=1
 176MOV_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
 184ADD_rri         1011 0000 0 .......             @addsub_sp_i
 185SUB_rri         1011 0000 1 .......             @addsub_sp_i
 186
 187# Branch and exchange
 188
 189@branchr        .... .... . rm:4 ...            &r
 190
 191BX              0100 0111 0 .... 000            @branchr
 192BLX_r           0100 0111 1 .... 000            @branchr
 193BXNS            0100 0111 0 .... 100            @branchr
 194BLXNS           0100 0111 1 .... 100            @branchr
 195
 196# Extend
 197
 198@extend         .... .... .. rm:3 rd:3          &rrr_rot rn=15 rot=0
 199
 200SXTAH           1011 0010 00 ... ...            @extend
 201SXTAB           1011 0010 01 ... ...            @extend
 202UXTAH           1011 0010 10 ... ...            @extend
 203UXTAB           1011 0010 11 ... ...            @extend
 204
 205# Change processor state
 206
 207%imod           4:1 !function=plus_2
 208
 209SETEND          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
 219REV             1011 1010 00 ... ...            @rdm
 220REV16           1011 1010 01 ... ...            @rdm
 221REVSH           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
 246HLT             1011 1010 10 imm:6              &i
 247BKPT            1011 1110 imm:8                 &i
 248CBZ             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
 255STM             1011 010 ......... \
 256                &ldst_block i=0 b=1 u=0 w=1 rn=13 list=%push_list
 257LDM_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
 274B               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.
 279BLX_suffix      11101 imm:11                    &i
 280BL_BLX_prefix   11110 imm:s11                   &i
 281BL_suffix       11111 imm:11                    &i
 282