Fix all modules to support loading after boot

klange / toaruos

A completely-from-scratch hobby operating system: bootloader, kernel, drivers, C library, and userspace including a composited graphical UI, dynamic linker, syntax-highlighting text editor, network stack, etc.

https://toaruos.org/

University of Illinois/NCSA Open Source License

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Fix all modules to support loading after boot #176

Closed klange closed 5 years ago

klange commented 5 years ago

Currently, several modules (especially driver modules) have issues with page mappings the require them to be loaded at boot. These can be fixed by either ensuring that they only access these memory regions in their own tasklets or by adding an interface to add global mappings after we've already started more processes.

If this is fixed, we can load driver modules after boot based on PCI-detected hardware from userspace, which would be neat.

klange commented 5 years ago

Specifically:

lfbvideo does a lot of this to map framebuffers. Can we possibly only map the framebuffer for a consumer process, maybe upon opening the device?
e1000 maps an MMIO region, which the IRQ handler needs, so that needs to be global.
vbox has a small mapping also needed by the IRQ handler.

klange commented 5 years ago

Preallocating the page tables for higher memory worked to resolve this issue, but I don't think it's a good long-term solution.