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Windows NT 3.x was a true microkernel. Microsoft ruined it but the design was quite good and the driver question was irrelevant, until they sidestepped HAL. T

Windows NT 3.x was a true microkernel. Microsoft ruined it but the design was quite good and the driver question was irrelevant, until they sidestepped HAL. The Linux kernel was and is a monstrosity.

WalterGR 10mo ago
What do you meant by them sidestepping the HAL?
- avadodin 10mo ago
  I think the biggest one is that the whole GDI library was moved into the Kernel in 3.5x because the performance was terrible at the time. I don't think they ever intended to keep all drivers strictly userland, though. Just the service side.
- nobodyandproud 10mo ago
  Mind you I don't have access to Microsoft code, so this is all indirect, and a lot of this knowledge was when I was fledgling developer. The Windows NT code was engineered to be portable across many different architectures--not just X86--so it has a hardware abstraction layer. The kernel only ever communicated to the device-driver implementation through this abstraction layer; so the kernel code itself was isolated. That doesn't mean the device drivers were running in user-land privilege, but it does mean that the kernel code is quite stable and easy to reason about. When Microsoft decided to compromise on this design, I remember senior engineers--when I first started my career--being abuzz about it for Windows NT 4.0 (or apparently earlier?).
pjmlp 10mo ago
This is outdated since Windows Vista, and even more so in Windows 11.
- nobodyandproud 10mo ago
  Windows Vista isn't Windows NT 3.x. In the internal versioning, it's not even 4.0.
  - pjmlp 10mo ago
    Indeed, it is something better, Windows NT 6.0. And it is irrelevant anyway, given that this comment was written from 10.0.26100.
    - nobodyandproud 10mo ago
      Oh, I see. You’re saying they improved the design. I know they added user-privilege device driver support for USB (etc).; did they revert the display compromise/mess as well?
      - pjmlp 9mo ago
        Yes, now graphics drivers are mostly in userspace, with only a tiny driver in kernel space, miniport. Hence why graphics usually no longer crash Windows, after a small black screen pause, everything continues as usual. https://learn.microsoft.com/en-us/windows-hardware/drivers/display/windows-vista-display-driver-model-design-guide https://learn.microsoft.com/en-us/windows-hardware/drivers/d...

Windows NT 3.x was a true microkernel. Microsoft ruined it but the design was quite good and the driver question was irrelevant, until they sidestepped HAL. The Linux kernel was and is a monstrosity.

WalterGR 10mo ago

What do you meant by them sidestepping the HAL?

avadodin 10mo ago
I think the biggest one is that the whole GDI library was moved into the Kernel in 3.5x because the performance was terrible at the time. I don't think they ever intended to keep all drivers strictly userland, though. Just the service side.
nobodyandproud 10mo ago
Mind you I don't have access to Microsoft code, so this is all indirect, and a lot of this knowledge was when I was fledgling developer. The Windows NT code was engineered to be portable across many different architectures--not just X86--so it has a hardware abstraction layer. The kernel only ever communicated to the device-driver implementation through this abstraction layer; so the kernel code itself was isolated. That doesn't mean the device drivers were running in user-land privilege, but it does mean that the kernel code is quite stable and easy to reason about. When Microsoft decided to compromise on this design, I remember senior engineers--when I first started my career--being abuzz about it for Windows NT 4.0 (or apparently earlier?).

pjmlp 10mo ago

This is outdated since Windows Vista, and even more so in Windows 11.

nobodyandproud 10mo ago
Windows Vista isn't Windows NT 3.x. In the internal versioning, it's not even 4.0.
- pjmlp 10mo ago
  Indeed, it is something better, Windows NT 6.0. And it is irrelevant anyway, given that this comment was written from 10.0.26100.
  - nobodyandproud 10mo ago
    Oh, I see. You’re saying they improved the design. I know they added user-privilege device driver support for USB (etc).; did they revert the display compromise/mess as well?
    - pjmlp 9mo ago
      Yes, now graphics drivers are mostly in userspace, with only a tiny driver in kernel space, miniport. Hence why graphics usually no longer crash Windows, after a small black screen pause, everything continues as usual. https://learn.microsoft.com/en-us/windows-hardware/drivers/display/windows-vista-display-driver-model-design-guide https://learn.microsoft.com/en-us/windows-hardware/drivers/d...