Messages in this thread | | | Date | Tue, 21 Feb 2023 16:18:35 +0100 | Subject | Re: [PATCH v3 2/2] scripts/decodecode: Add support for RISC-V | From | Alexandre Ghiti <> |
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Hi Björn,
On 1/19/23 08:47, Björn Töpel wrote: > From: Björn Töpel <bjorn@rivosinc.com> > > RISC-V has some GNU disassembly quirks, e.g. it requires '-D' to > properly disassemble .2byte directives similar to Arm [1]. Further, > GNU objdump groups RISC-V instruction by 2 or 4 byte chunks, instead > doing byte-for-byte. > > Add the required switches, and translate from short/word to bytes when > ARCH is "riscv". > > An example how to invoke decodecode for RISC-V: > $ echo 'Code: bf45 f793 1007 f7d9 50ef 37af d541 b7d9 7097 00c8 (80e7) > 6140' | AFLAGS="-march=rv64imac_zicbom_zihintpause" \ > ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- ./scripts/decodecode > Code: bf45 f793 1007 f7d9 50ef 37af d541 b7d9 7097 00c8 (80e7) 6140 > All code > ======== > 0: bf45 c.j 0xffffffffffffffb0 > 2: 1007f793 andi a5,a5,256 > 6: f7d9 c.bnez a5,0xffffffffffffff94 > 8: 37af50ef jal ra,0xf5382 > c: d541 c.beqz a0,0xffffffffffffff94 > e: b7d9 c.j 0xffffffffffffffd4 > 10: 00c87097 auipc ra,0xc87 > 14:* 614080e7 jalr ra,1556(ra) # 0xc87624 <-- trapping instruction > > Code starting with the faulting instruction > =========================================== > 0: 614080e7 jalr ra,1556(ra) > > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=10263 > > Signed-off-by: Björn Töpel <bjorn@rivosinc.com> > --- > scripts/decodecode | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/scripts/decodecode b/scripts/decodecode > index b28fd2686561..8fe71c292381 100755 > --- a/scripts/decodecode > +++ b/scripts/decodecode > @@ -93,6 +93,11 @@ disas() { > ${CROSS_COMPILE}strip $t.o > fi > > + if [ "$ARCH" = "riscv" ]; then > + OBJDUMPFLAGS="-M no-aliases --section=.text -D" > + ${CROSS_COMPILE}strip $t.o > + fi > + > if [ $pc_sub -ne 0 ]; then > if [ $PC ]; then > adj_vma=$(( $PC - $pc_sub )) > @@ -126,8 +131,13 @@ get_substr_opcode_bytes_num() > do > substr+="$opc" > > + opcode="$substr" > + if [ "$ARCH" = "riscv" ]; then > + opcode=$(echo $opcode | tr ' ' '\n' | tac | tr -d '\n') > + fi > + > # return if opcode bytes do not match @opline anymore > - if ! echo $opline | grep -q "$substr"; > + if ! echo $opline | grep -q "$opcode"; > then > break > fi
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Thanks, that's very useful!
Alex
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