SECTION .text   align=0
[bits 32]

%include "eelstd.h"

		GLOBAL	r_bytes
		GLOBAL	m_alloc
		GLOBAL	dm_alloc

		GLOBAL	get_physmem
		GLOBAL	RAM

RAM	dd	0

get_physmem:	xor	eax,eax
		mov	ebp,0xC0CAC01A
		mov	ecx,4095
		mov	ebx,1024*1024

.check:		mov	edx,[ebx]
		mov	[ebx],ebp

		jmp	$+2

		cmp	[ebx],ebp
		jne	.no_more_ram

		mov	[ebx],edx
		add	ebx,1024*1024
		loop	.check

.no_more_ram:	mov	[RAM],ebx
		ret
		


; Allocates a chunc of memory (not very efficient for the moment, but it works..)
;
; IN: ecx = length in 4kb blocks
;
; OUT: eax = 0 if successfull
;      esi -> absolute address of block
;

r_bytes	dd	0

m_alloc:        cld
		push    esi
                push    ecx
		push	edx
		push	ds

		push	byte data32
		pop	ds

		mov	edx,ecx
		mov	[r_bytes],ecx
                xor     esi,esi
                mov     ecx,1024*4

.scan_block:    lodsd
                test    eax,800h
                jnz     .not_free

		dec	edx
		jz	.found_block
                jmp     .scan_block

.not_free:	mov	edx,[r_bytes]
		loop	.scan_block

		mov	al,0ffh
		jmp	.mal_exit

.found_block:   push    esi
                mov     eax,[r_bytes]
                shl     eax,2
                sub     esi,eax
		mov	eax,[esi]
		and	eax,0fffff000h
		mov	esi,eax

                pop     eax
                mov     ecx,[r_bytes]
.alloc_mem:     or      dword [eax-4],800h	;changes... lodsd = mov eax,[esi]; add esi,4
                sub     eax,byte 4
		loop	.alloc_mem

                pop     ds
                pop     edx
                pop     ecx
                pop     eax     ;NOT esi

                xor     eax,eax

                popfd
                iretd

.mal_exit:      pop     ds
		pop	edx
		pop	ecx
		pop	esi

                popfd
                iretd


; Deallocates a memory block
;
; IN: esi -> absolute address of block
;     ecx =  number of 4kb blocks to deallocate
;
; OUT: eax = 0 if successfull
;


dm_alloc:       push    ds
		push	ecx
		push	esi

		push	byte data32
		pop	ds

                shr     esi,10

.dealloc:	and	dword [esi],0fffff7ffh
                add     esi,byte 4
		loop	.dealloc

                xor     eax,eax

                pop     esi
		pop	ecx
		pop	ds
		popfd
		iretd