From: Duje Mihanović <duje.mihanovic@skole.hr>
Date: Mon, 27 Jun 2022 19:33:06 +0000 (+0200)
Subject: Remove leftover paging.s from merge
X-Git-Url: http://git.dujemihanovic.xyz/%22http:/www.sics.se/static/%7B%7B%20.Permalink%20%7D%7D?a=commitdiff_plain;h=1e4f7922ce4a13857474e457ca51f20d3555b707;p=nameless-os.git

Remove leftover paging.s from merge
---

diff --git a/boot/x86/stage3/loader.s b/boot/x86/stage3/loader.s
index bd2fb9b..87598f4 100644
--- a/boot/x86/stage3/loader.s
+++ b/boot/x86/stage3/loader.s
@@ -210,5 +210,3 @@ ss_s: db "SS: ", 0
 space: db " ", 0
 hex_delm: db "0x", 0
 newline: db 0xd, 0xa, 0
-
-%include "paging.s"
diff --git a/boot/x86/stage3/paging.s b/boot/x86/stage3/paging.s
deleted file mode 100644
index 004da84..0000000
--- a/boot/x86/stage3/paging.s
+++ /dev/null
@@ -1,80 +0,0 @@
-; Code for enabling paging before calling the kernel
-; Identity maps the VGA framebuffer memory and high-half maps the kernel memory
-bits 32
-
-section .text
-
-; The problem with this code is that it assumes that the kernel's various
-; sections occupy a certain number of pages. As of writing it is correct, but as
-; the kernel grows this code may fail to map those pages, which is not good. The
-; solution to this is to use ELF instead of a flat binary. This was not done
-; before because it would require paging, but now that paging works using ELF is
-; a possibility which must be exploited.
-
-enable_paging:
-	push eax
-	mov eax, cr0
-	or eax, 0x80000000
-	mov cr0, eax
-	pop eax
-	ret
-
-load_paging_structs:
-	push eax
-	push ebx
-	xor ebx, ebx
-.pt_low_loop:
-	mov eax, ebx
-	shl eax, 12
-	or eax, 1|2 ; P and R/W flags
-	mov [page_table_low+ebx*4], eax
-	inc ebx
-	cmp ebx, 0x100
-	jl .pt_low_loop
-
-	xor ebx, ebx
-.pt_high_ro_loop:
-	mov eax, ebx
-	add eax, 0x100
-	shl eax, 12
-	or eax, 1 ; P flag
-	mov [page_table_high+ebx*4], eax
-	inc ebx
-	cmp ebx, 0x2
-	jl .pt_high_ro_loop
-
-	mov ebx, 0x2
-.pt_high_rw_loop:
-	mov eax, ebx
-	add eax, 0x100
-	shl eax, 12
-	or eax, 1|2 ; P and R/W flags
-	mov [page_table_high+ebx*4], eax
-	inc ebx
-	cmp ebx, 0x9
-	jl .pt_high_rw_loop
-
-	mov eax, page_table_low
-	and eax, 0xfffff000
-	or eax, 1|2
-	mov [page_directory], eax
-
-	mov eax, page_table_high
-	and eax, 0xfffff000
-	or eax, 1|2
-	mov [page_directory+768*4], eax
-
-	mov eax, page_directory
-	mov cr3, eax
-	pop ebx
-	pop eax
-	ret
-
-section .data
-align 4096
-page_table_low:
-	times 1024 dd 0
-page_table_high:
-	times 1024 dd 0
-page_directory:
-	times 1024 dd 0