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Re: Stupid question



On Saturday, February 12, 2022 04:04:43 AM Hans wrote:
> But how can I tell grub, to use the kernel of the second /boot?
> 
> I dunno, if it is possible at all, to get a dual boot, the way I want it.
> With a combination of Windows + Linux on one harddrive this is working,
> however, just because grub does not touch the windows bootloader (as fas
> as I know), and what of course is also working, if you got two harddrives,
> each with different linux. They all can be booted from one grub
> installation, of course.
> 
> Maybe I could find a solution, if I would have fully understood how grub is
> working, and what it is doing.
> 
> Any hints are welcome, and if this does never work at all, please drop me a
> line.

The way I understand it (but I may be misremembering), grub temporaily boots 
into a, well I'll say restricted Linux kernel and OS which is used by grub 
until it boots up the main system.  The kernel used in grub may not (probably 
doesn't match the kernel used after grub brings up the main system, and it wil 
bring up the appropriate kernel for that main system (the one you choose).

Think about grub bringing up a Windows system -- grub doesn't use a Windows 
kernel in that case but uses that restricted (mcow) Linux kernel to bring up 
Windows, but Windows doesn't use a Linux kernel once it is up and running.

Further, iirc, the Linux kernel in Grub (I guess I should write it GRUB) is 
contained in an image file that is loaded into RAM on a temporary basis until 
the main OS is brought up.

I guess it is possible, but it is hard (for me) to imagine a need to have that 
GRUB kernel match the kernel that will be used after the main OS is running.


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