The moment any Windows based on NT begins booting, the system is in protected mode. […] Nothing else is allowed to run - nothing else can run. The CPU is executing only the Windows kernel code.
Assuming the author isn’t talking about some Windows-specific feature that’s also called “protected mode”, that’s not really true. Protected mode just means that you can use paging. Once the system boots, it remains in protected mode (ignoring 64-bit long mode shenanigans), and userland programs can run just fine.
I’d also assume that by the point you see the progress bar, the system already can load third-party drivers, for graphics and such.
btw, QuickLook seems wonderfully cursed. I’d love to try it out.
Let me reiterate: Certain HP laptops have three power buttons that launch different OSes.
Half my life ago, the last time I was dual-booting Linux and Windows, I kept thinking about having different “Windows” and “Linux” buttons instead of a single power button. I was far too inexperienced to know if that was even possible, never mind how.
Turns out instead of building my own desktop I should have just bought a cheap HP netbook.
I recall a tool that spat out floppy disk boot sectors that would chain boot a specific partition on an IDE disk. The intended use case was precisely this: you could set up your computer to boot Windows from the disk and boot from A: before C:, so if the floppy disk was in the drive you’d boot Linux / *BSD, if it wasn’t then you’d boot Windows. When a Windows update overwrote your boot sector, you didn’t lose the ability to boot your other OS.
Assuming the author isn’t talking about some Windows-specific feature that’s also called “protected mode”, that’s not really true. Protected mode just means that you can use paging. Once the system boots, it remains in protected mode (ignoring 64-bit long mode shenanigans), and userland programs can run just fine.
I’d also assume that by the point you see the progress bar, the system already can load third-party drivers, for graphics and such.
btw, QuickLook seems wonderfully cursed. I’d love to try it out.
yeah, I’m pretty sure “nothing else” was meant to come across as “for example, not any other kernels or bootloader extensions”
Half my life ago, the last time I was dual-booting Linux and Windows, I kept thinking about having different “Windows” and “Linux” buttons instead of a single power button. I was far too inexperienced to know if that was even possible, never mind how.
Turns out instead of building my own desktop I should have just bought a cheap HP netbook.
Here’s one way to do it https://hackaday.io/project/179539-hardware-boot-selection-switch
I had a machine with a “button” to boot a different OS… well it was the floppy disk with LILO.
I recall a tool that spat out floppy disk boot sectors that would chain boot a specific partition on an IDE disk. The intended use case was precisely this: you could set up your computer to boot Windows from the disk and boot from A: before C:, so if the floppy disk was in the drive you’d boot Linux / *BSD, if it wasn’t then you’d boot Windows. When a Windows update overwrote your boot sector, you didn’t lose the ability to boot your other OS.