Bochs User Manual
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# Common problems and what to do about them (Troubleshooting)

          How to report a panic to the bug tracker?
          Keyboard mapping problems
          [...]

# Bochs panics! What can I do?

Bochs does a very good job in emulating an x86 compatible computer, however, it does not (yet) include a full (100%) emulation of every possible instruction, (BIOS) function call or (hardware) device. Thus, in case something unusual happens, either a not-so-common call to some (BIOS) function or device by some software running inside of it, Bochs has two possibilities to react: If the command doesn't look important (mainly happens only to non-implemented functions in the BIOS), a notice is logged to the log file and the emulation continues. If, however, the command looks important, Bochs panics, because the software being emulated might depend on the successful execution of the given instruction or behaviour of the device.

A panic does not always mean that the software won't run inside of Bochs, as the software might just be probing the computer for the presence of some instruction/device, and in case it is not found, it simply won't be used at all, by the software.

You can tell Bochs what to do in case of a panic, by re-configuring the panic option. If you change the action to "ask", Bochs reports what has happened and asks you what to do. The appearance of the "ask" feature depends on the display library used and the platform. Some display libraries don't support it at all.

Some of the device names reported in the panic message are abbreviations, since the length of the names is limited to 5 characters. This small list may help you finding out the name of the device that caused the panic.

Table 1. Device prefixes

Prefix | Description
--- | ---
CLVGA | Cirrus SVGA
EFIRQ | External FPU IRQ
IOAP | I/O APIC
KMAP | Keyboard mapping
P2I | PCI-to-ISA bridge
PIDE | PCI IDE controller
PLGIN | Plugin interface
STIME | Slowdown timer
UNMP | Unmapped I/O handler
VTIME | Virtual timer

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