Commit Graph

9 Commits

Author SHA1 Message Date
Eric-Paul Ickhorn f573f49874
Fix GDT error offsetting memory by some bytes
The error in the GDT caused the whole memory space to be offset by
128B or 256B (It's not entirely sure which one of those). This was
only made visible by later changes, but now it's fixed.
2024-07-19 00:12:52 +02:00
Eric-Paul Ickhorn 44ca45e8f1
Finish up GDT, get linear address space working
The GDT is now finally set and produces a linear address space.
Execution continues at 'stage2_true_entry'.
2024-07-06 00:12:07 +02:00
Eric-Paul Ickhorn 0d49245a60
Delete GDT-related files
This commit deletes the gdt.asm for the i386 architecture as it was
quite buggy in that state. In a short while, the real GDT code which
works is going to be committed.
2024-07-06 00:12:06 +02:00
Eric-Paul Ickhorn 993864e364
Save progess, then delete GDT for rewrite
This commit saves the progress made on the GDT; the files are deleted
quickly thereafter as the code was quite buggy.
2024-07-06 00:12:06 +02:00
Eric-Paul Ickhorn 83eb29d55c
Try to fix GDT; unsuccessful
This commit just existed because of a misunderstanding leading to the
belief that the GDT was finally working; it wasn't though.
2024-07-06 00:12:06 +02:00
Eric-Paul Ickhorn 5180348c39
Add stage 2 loader entry point
This commit adds the entry point for the second stage of the loader.
It currently doesn't contain a lot of code, but it will have to expand
in the next bit of time.
2024-07-06 00:08:57 +02:00
Eric-Paul Ickhorn d773a8f9e2
Add memory utilities and math utils
This commit adds the well known primitive memory functions:

- Copy Memory
- Compare Memory for being equal
- Set Memory to a value

It also adds a math utility file at the according location.
2024-07-06 00:07:08 +02:00
Eric-Paul Ickhorn c3f2c7fbfc
Intermediate commit to add GDT
In this commit, it was tried to set a linear GDT. It didn't work; but
in the future, it will.
2024-07-06 00:05:17 +02:00
Eric-Paul Ickhorn 94a228b278
Add A20 line check
This commit adds a check for whether the A20 line is usable; checking
whether more than one megabyte of RAM can be used. If it isn't usable,
it currently isn't activated, but rather, the boot process is stopped.
2024-07-06 00:03:48 +02:00