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Diffstat (limited to 'opcode-gen/README.txt')
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diff --git a/opcode-gen/README.txt b/opcode-gen/README.txt new file mode 100644 index 0000000..a210842 --- /dev/null +++ b/opcode-gen/README.txt @@ -0,0 +1,74 @@ +# Copyright (C) 2010 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +--------------------------------------------------------------------- +Notes on updating the sets of defined opcodes and instruction formats +--------------------------------------------------------------------- + +########## + +If you want to add, delete, or change opcodes: + +* Update the file bytecode.txt, in this directory. + +* Run the regen-all script, in this directory. This will regenerate a + number of tables, definitions, and declarations in the code, in + dalvik/dx, dalvik/libdex, and libcore/dalvik. + +* Implement/update the opcode in C in vm/mterp/c/... + * Verify new code by running with "dalvik.vm.execution-mode = int:portable" + or "-Xint:portable". + +* Implement/update the instruction in assembly in vm/mterp/{arm*,x86*}/... + * Verify by enabling the assembly (e.g. ARM) handler for that instruction + in mterp/config-* and running "int:fast" as above. + +* Implement/update the instruction in + vm/compiler/codegen/{arm,x86}/CodegenDriver.c. + +* Rebuild the interpreter code. See the notes in vm/mterp/ReadMe.txt for + details. + +* Look in the directory vm/analysis at the files CodeVerify.c, + DexVerify.c, and Optimize.c. You may need to update them to account + for your changes. + * If you change anything here, be sure to try running the system with + the verifier enabled (which is in fact the default). + +########## + +If you want to add, delete, or change instruction formats: + +This is a more manual affair than changing opcodes. + +* Update the file bytecode.txt, and run regen-all, as per above. + +* Update the instruction format list in libdex/InstrUtils.h. + +* Update dexDecodeInstruction() in libdex/InstrUtils.c. + +* Update dumpInstruction() and its helper code in dexdump/DexDump.c. + +* Update the switch inside dvmCompilerMIR2LIR() in + vm/compiler/codegen/{arm,x86}/CodegenDriver.c. (There may be other + architectures to deal with too.) + +########## + +Testing your work: + +The Dalvik VM tests (in the vm/tests directory) provide a convenient +way to test most of the above without doing any rebuilds. In +particular, test 003-omnibus-opcodes will exercise most of the +opcodes. |