Use instruction-based emulation for debug mode #530
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Benchmarks
| Benchmark suite | Current: ecb20c8 | Previous: 158597a | Ratio |
|---|---|---|---|
Dhrystone |
1346 Average DMIPS over 10 runs |
1329 Average DMIPS over 10 runs |
0.99 |
Coremark |
950.448 Average iterations/sec over 10 runs |
973.118 Average iterations/sec over 10 runs |
1.02 |
This comment was automatically generated by workflow using github-action-benchmark.
RinHizakura
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| static void rv_check_interrupt(riscv_t *rv) | ||
| { | ||
| vm_attr_t *attr = PRIV(rv); | ||
| /* check for any interrupt after every block/instruction emulation */ |
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Move this comment to the beginning of the while loop in the rv_step since rv_step_debug call it step by step.
| assert(arg); | ||
| riscv_t *rv = arg; | ||
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| rv_check_interrupt(rv); |
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How about modify here like following?
#if RV32_HAS(SYSTEM) && !RV32_HAS(ELF_LOADER)
rv_check_interrupt(rv);
#endif
In this way, the dummy rv_check_interrupt can be removed.
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The debug mode of system simulation is not supported yet. Should we remove this statement to avoid ambiguity?
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What does "debug mode of system simulation is not supported" mean here? The debug/gdbstub mode should be supported naturally because there's no big difference between program or system emulation. I already checked that we could read/write the register, set the breakpoint and step instructions on system emulation.
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Would rv32emu support debugging with booting Linux Kernel now? I failed to run file build/linux-image/Image in riscv32-unknown-elf-gdb to launch the remote GDB since it is not the RISC-V executable.
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Yes. Please use the vmlinux file, Image is not the right one. By the way, you can skip the step to link GDB to an ELF file if you don't need any debug symbol(i.e. just run target remote :1234 and start debugging).
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You can check like this
- Open a bash shell and run
./build/rv32emu -k build/linux-image/Image -i build/linux-image/rootfs.cpio -b build/minimal.dtb -g - Open another shell and run
riscv32-unknown-elf-gdb -ex "target remote :1234" -ex "cont" - You can see the emulator start executing in the first shell
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Oh, it works. Thank you to point it out. Can you also update the document for this? (maybe in another PR)
In debug mode(gdbstub), we'll need one instruction/cycle per step for trace. For such usecase, using the block-based emulation will be too expensive which slow down the execution. Switch to instruction-based emulation for debug mode.
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Thank @RinHizakura for contributing! |
Use instruction-based emulation for debug mode
In debug mode(gdbstub), we'll need one instruction/cycle per step for trace. For such usecase, using the block-based emulation will be too expensive which slow down the execution. Switch to instruction-based emulation for debug mode.