Re: "The installed loader is a binary, not a filesystem, so even minor changes require recompiling." -George W. Lucas in Absolute fBSD

On 12/18/23 3:17 PM, Jop wrote:
Um, Michael W. Lucas , not George...

> Hello everyone,
> 
> I have just begun my journey into FreeBSD using George W. Lucas' 
> /Absolute FreeBSD /3rd edition/./ My question is about *chapter 4* 
> /Start Me Up! The Boot Process,/ page 51.
> I was befuddled by a statement he made, likely due to my IT nescience.
> To my confusion, Lucas states:
> 
>     > A BIOS has all sorts of limitations. The boot loader must reside in a very specific section of the disk. BIOS can’t boot from disks larger
>     than 2.2TB. The target boot loader must be smaller than 512KB—huge
>     by 1980
>      >standards, yes, but paltry today. :::**​*The installed loader is a
>     binary, not a filesystem, so even minor changes require recompiling
>     *:::*.*
> 
> 
> Though this aspect of his introduction to FreeBSD is not about FreeBSD 
> directly, it seems vital for me to understand this correctly so that I 
> can aptly understand FreeBSD as a sheer operating system and how an 
> operating system boots. I was confused about Lucas' description because 
> he is implying there are /some /conditions in which a bootloader can be 
> an actual /filesystem/. This appears very illogical to me, as to me he 
> seems to be saying the loader itself should be something like FAT32, 
> UFS, or ZFS. Though filesystems, if my understanding is correct, help us 
> /organise /our data, they do not themselves /contain /data but rather 
> offer an organised space /for /that data, like a library with empty 
> bookshelves that we are ourselves to fill. Hence, if that "library" does 
> not contain a bit of data (e.g. the bootloader) that tells the BIOS how 
> to boot the operating system, the operating system cannot boot. Hence, 
> it is logically implied that the bootloader cannot be called in itself a 
> filesystem—not just /sometimes /under some conditions, but /ever/.
> As I trust Lucas' expertise, how have I misread him? What is he actually 
> trying to say?
> 
> I have searched online, and read a Wiki on bootloaders 
> <https://en.wikipedia.org/wiki/Bootloader>and filesystems 
> <https://en.wikipedia.org/wiki/Bootloader>, only to have my asinine 
> interpretation confirmed.
> 
> Now, one a second note, I am new to the FreeBSD community, I have not 
> before used mailing lists, and the FreeBSD forums were down. I 
> understand IT communities can be strict about what and how things are 
> communicated, and I hope i have done right by sending this email. I hope 
> that I have done sufficient research by searching online, consulting the 
> WiKi pages, the mailing list archives, and of course Lucas' book. I hope 
> that my question is on-topic enough and that my beginner-level will not 
> stagnate the flow of your erudite communications. Should I have not 
> utilised this mailing list properly, kindly accept my apologies and let 
> me know.
> 
> Sincerely,
> 
> /J./