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That sounds interesting! Out of curiosity, what is your use case for those features?
by 8_hours_ago 8y ago
That sounds interesting! Out of curiosity, what is your use case for those features?
- burfog 8y agoIt is useful for backwards execution. This is supported in various ways by Simics, gdb, SID simulator, rr, the Moxielogic emulator, and others. It is useful for virtual machine snapshots. You can restore the virtual machine with the terminal state intact.
- gear54rus 8y agoAm I missing something? VM snapshots also save memory, any terminal will be intact after this?
- burfog 8y agoThat would be true if the terminal were within the VM, for example if the VM was a graphical OS running a terminal program. It isn't true if the VM is communicating over an emulated serial port. In that case, the VM software must provide a terminal as hardware. Typically the VM software only provides a serial port to the VM, which the user will then associate with something else via the VM configuration. This fails when loading a snapshot because the terminal isn't part of the snapshot. For example, suppose that the VM is a PC-AT running DR-DOS and a BBS. (from the pre-internet days, with a modem for users to dial in on) At minimum, the VM software must provide a serial port for the VM. You could configure this to connect with a real physical modem and then connect to that with another modem and some dial-up software, but then you'd have a problem with snapshots. Loading a snapshot would place the BBS in a state that is inconsistent with the dial-up software. What you really need is for the terminal emulator to be part of the hardware that the VM is emulating. It would then be properly snapshotted.