StupidOS/kernel/vm/pmap.s

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2023-07-12 09:33:08 +00:00
;; File: pmap.s
;; Physical Memory Map
;; Structure: pmap_block
;;
;; .next - pointer to next pmap_block struct
;; .phys_start - start physical address of memory range
;; .phys_end - stop address of memory range
;; .bitmap_size - bitmap size (max: 0xFF0)
;; .last_alloc - last allocated frame in bitmap
;; .bitmap - bitmap array
;;
;; > pmap_block
;; > 0x0000 +-------------+
;; > | next |-----> pmap_block
;; > 0x0004 +-------------+ +----------+
;; > | phys start | | next |----> NULL (0x0)
;; > 0x0008 +-------------+ +----------+
;; > | phys end | | ..... |
;; > 0x000C +-------------+ | ..... |
;; > | bitmap size | | ..... |
;; > 0x000e +-------------+ +----------+
;; > | last alloc |
;; > 0x0010 +-------------+
;; > | bitmap |
;; > 0x???? +-------------+ (bitmap size * 4)
;;
struct pmap_block
.next: resd 1
.phys_start: resd 1
.phys_end: resd 1
.bitmap_size: resw 1
.last_alloc: resw 1
.bitmap:
endstruc
section .text
;; Function: pmap_bootstrap
;;
;; (see pmap_bootstrap.png)
pmap_bootstrap:
push esp
mov esp, ebp
leave
ret