From 6a7f57668afcd841e8fc6b507a27bb20e9209fa9 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Sat, 18 Sep 2021 10:42:41 +0100 Subject: [PATCH] riscv: print .2byte or .4byte before an unknown instruction encoding When the RISC-V disassembler encounters an unknown instruction, it currently just prints the value of the bytes, like this: Dump of assembler code for function custom_insn: 0x00010132 <+0>: addi sp,sp,-16 0x00010134 <+2>: sw s0,12(sp) 0x00010136 <+4>: addi s0,sp,16 0x00010138 <+6>: 0x52018b 0x0001013c <+10>: 0x9c45 My proposal, in this patch, is to change the behaviour to this: Dump of assembler code for function custom_insn: 0x00010132 <+0>: addi sp,sp,-16 0x00010134 <+2>: sw s0,12(sp) 0x00010136 <+4>: addi s0,sp,16 0x00010138 <+6>: .4byte 0x52018b 0x0001013c <+10>: .2byte 0x9c45 Adding the .4byte and .2byte opcodes. The benefit that I see here is that in the patched version of the tools, the disassembler output can be fed back into the assembler and it should assemble to the same binary format. Before the patch, the disassembler output is invalid assembly. I've started a RISC-V specific test file under binutils so that I can add a test for this change. binutils/ChangeLog: * testsuite/binutils-all/riscv/riscv.exp: New file. * testsuite/binutils-all/riscv/unknown.d: New file. * testsuite/binutils-all/riscv/unknown.s: New file. opcodes/ChangeLog: * riscv-dis.c (riscv_disassemble_insn): Print a .%dbyte opcode before an unknown instruction, '%d' is replaced with the instruction length. --- binutils/ChangeLog | 6 ++++ .../testsuite/binutils-all/riscv/riscv.exp | 29 +++++++++++++++++++ .../testsuite/binutils-all/riscv/unknown.d | 11 +++++++ .../testsuite/binutils-all/riscv/unknown.s | 27 +++++++++++++++++ opcodes/ChangeLog | 6 ++++ opcodes/riscv-dis.c | 24 ++++++++++++++- 6 files changed, 102 insertions(+), 1 deletion(-) create mode 100644 binutils/testsuite/binutils-all/riscv/riscv.exp create mode 100644 binutils/testsuite/binutils-all/riscv/unknown.d create mode 100644 binutils/testsuite/binutils-all/riscv/unknown.s diff --git a/binutils/ChangeLog b/binutils/ChangeLog index 858df6570ba..b9ac30976e4 100644 --- a/binutils/ChangeLog +++ b/binutils/ChangeLog @@ -1,3 +1,9 @@ +2021-09-20 Andrew Burgess + + * testsuite/binutils-all/riscv/riscv.exp: New file. + * testsuite/binutils-all/riscv/unknown.d: New file. + * testsuite/binutils-all/riscv/unknown.s: New file. + 2021-09-07 Luis Machado Revert: [AArch64] MTE corefile support diff --git a/binutils/testsuite/binutils-all/riscv/riscv.exp b/binutils/testsuite/binutils-all/riscv/riscv.exp new file mode 100644 index 00000000000..8f0b7dc9766 --- /dev/null +++ b/binutils/testsuite/binutils-all/riscv/riscv.exp @@ -0,0 +1,29 @@ +# Copyright (C) 2021 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. + +if ![istarget "riscv*-*-*"] then { + return +} + +set tempfile tmpdir/riscvtemp.o +set copyfile tmpdir/riscvcopy + +set test_list [lsort [glob -nocomplain $srcdir/$subdir/*.d]] +foreach t $test_list { + # We need to strip the ".d", but can leave the dirname. + verbose [file rootname $t] + run_dump_test [file rootname $t] +} diff --git a/binutils/testsuite/binutils-all/riscv/unknown.d b/binutils/testsuite/binutils-all/riscv/unknown.d new file mode 100644 index 00000000000..64791169b2a --- /dev/null +++ b/binutils/testsuite/binutils-all/riscv/unknown.d @@ -0,0 +1,11 @@ +#as: -march=rv32ic +#objdump: -d +# Test the disassembly of unknown instruction encodings, specifically, +# ensure that we generate a .?byte opcode. + +#... +Disassembly of section \.text: + +[0-9a-f]+ <\.text>: + [0-9a-f]+: 0052018b \.4byte 0x52018b + [0-9a-f]+: 9c45 \.2byte 0x9c45 diff --git a/binutils/testsuite/binutils-all/riscv/unknown.s b/binutils/testsuite/binutils-all/riscv/unknown.s new file mode 100644 index 00000000000..df929047fef --- /dev/null +++ b/binutils/testsuite/binutils-all/riscv/unknown.s @@ -0,0 +1,27 @@ +/* Copyright (C) 2021 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + + .text + /* The following instruction is in the area set aside for + custom instruction extensions. As such it is unlikely that + an upstream extension should ever clash with this. */ + .insn r 0x0b, 0x0, 0x0, x3, x4, x5 + /* Unlike the above, the following is just a reserved + instruction encoding. This means that in the future an + extension to the compressed instruction set might use this + encoding. If/when that happens we'll need to find a + different unused encoding within the compressed instruction + space. */ + .insn ca 0x1, 0x27, 0x2, x8, x9 diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog index ca3206dda6d..a32af60864d 100644 --- a/opcodes/ChangeLog +++ b/opcodes/ChangeLog @@ -1,3 +1,9 @@ +2021-09-20 Andrew Burgess + + * riscv-dis.c (riscv_disassemble_insn): Print a .%dbyte opcode + before an unknown instruction, '%d' is replaced with the + instruction length. + 2021-09-02 Nick Clifton PR 28292 diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c index 57198c7b6b5..2e28ba77e60 100644 --- a/opcodes/riscv-dis.c +++ b/opcodes/riscv-dis.c @@ -570,7 +570,29 @@ riscv_disassemble_insn (bfd_vma memaddr, insn_t word, disassemble_info *info) /* We did not find a match, so just print the instruction bits. */ info->insn_type = dis_noninsn; - (*info->fprintf_func) (info->stream, "0x%llx", (unsigned long long)word); + switch (insnlen) + { + case 2: + case 4: + case 8: + (*info->fprintf_func) (info->stream, ".%dbyte\t0x%llx", + insnlen, (unsigned long long) word); + break; + default: + { + int i; + (*info->fprintf_func) (info->stream, ".byte\t"); + for (i = 0; i < insnlen; ++i) + { + if (i > 0) + (*info->fprintf_func) (info->stream, ", "); + (*info->fprintf_func) (info->stream, "0x%02x", + (unsigned int) (word & 0xff)); + word >>= 8; + } + } + break; + } return insnlen; } -- 2.30.2