73 lines
1.3 KiB
Markdown
73 lines
1.3 KiB
Markdown
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# Reverse Execution Demo
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This is a demo showcasing Renode's support for GDB reverse execution.
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## Running the demo
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1. `gdb_reverse_execution.resc` Renode script creates a RISC-V machine with small assembly printing to UART.
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```bash
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renode scripts/complex/reverse_execution/gdb_reverse_execution.resc
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```
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2. Use `script.gdb` GDB script to easily connect to Renode with preset breakpoints.
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```bash
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gdb -x script.gdb
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```
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3. Follow the flow of the demonstration
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```
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Breakpoint 1, 0x80000000 in ?? ()
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(gdb) continue
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Continuing.
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Breakpoint 2, 0x80000014 in ?? ()
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(gdb) continue
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Continuing.
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Breakpoint 3, 0x8000003a in ?? ()
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```
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Now you can see `:(` printed on UART.
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4. Execute `reverse-*` commands in GDB:
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```
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(gdb) reverse-continue
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Continuing.
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Breakpoint 2, 0x80000014 in ?? ()
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(gdb) reverse-stepi
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0x80000010 in ?? ()
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(gdb) rsi
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0x8000000e in ?? ()
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(gdb) rc
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Continuing.
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Breakpoint 1, 0x80000000 in ?? ()
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(gdb)
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```
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5. Set `t4` register to `0x1337` to branch in `beq t3, t4, ok` test.
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```
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(gdb) set $t4=0x1337
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(gdb) continue
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Continuing.
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Breakpoint 2, 0x80000014 in ?? ()
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(gdb) continue
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Continuing.
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Breakpoint 3, 0x8000003a in ?? ()
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(gdb)
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```
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Spot `OK` on UART console!
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---
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For more information visit [Renode documentation](https://renode.readthedocs.io/en/latest/debugging/gdb.html#reverse-execution)
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