virtual at 0 physical_mem_block: .start rd 1 .size rd 1 .flags rd 1 ;0-free, pid-used. .sizeof: end virtual max_physical_mem_blocks = 24 uglobal num_physical_mem_blocks rd 1 physical_mem_blocks rd 3*max_physical_mem_blocks endg Init_Physical_Memory_Manager: pushad mov edi,physical_mem_blocks mov ecx,3*max_physical_mem_blocks xor eax,eax cld rep stosd mov dword [num_physical_mem_blocks],2 mov [physical_mem_blocks+physical_mem_block.start],0x60000 mov [physical_mem_blocks+physical_mem_block.size],0x20000 ;128Kb mov [physical_mem_blocks+physical_mem_block.sizeof+physical_mem_block.start],0x780000 mov [physical_mem_blocks+physical_mem_block.sizeof+physical_mem_block.size],0x80000 ;512Kb popad ret Insert_Block: ;input: ; eax - handle ;output: ; none push eax ecx esi edi sub eax,[num_physical_mem_blocks] neg eax mov edi,physical_mem_block.sizeof imul eax,edi shr eax,2 mov ecx,eax mov esi,[num_physical_mem_blocks] imul esi,edi add esi,physical_mem_blocks lea edi,[esi+physical_mem_block.sizeof] std rep movsd pop edi esi ecx eax ret Delete_Block: ;input: ; eax - handle ;output: ; none pushad mov edi,eax sub eax,[num_physical_mem_blocks] neg eax dec eax mov esi,physical_mem_block.sizeof imul eax,esi imul edi,esi add edi,physical_mem_blocks lea esi,[edi+physical_mem_block.sizeof] mov ecx,eax shr ecx,2 cld rep movsd popad ret Allocate_Physical_Block: ;input: ; eax - size ;output: ; eax - address or 0 if not enough memory. pushad cmp [num_physical_mem_blocks],max_physical_mem_blocks jge .error mov ebx,eax xor eax,eax mov esi,physical_mem_blocks .loop: cmp dword [esi+physical_mem_block.flags],0 jnz .next cmp [esi+physical_mem_block.size],ebx jg .addblock jz .noaddblock .next: inc eax add esi,physical_mem_block.sizeof cmp eax,[num_physical_mem_blocks] jl .loop .error: popad xor eax,eax ret .noaddblock: mov eax,[esi+physical_mem_block.start] mov [esp+28],eax mov eax,[0x3010] mov eax,[eax+0x4] mov [esi+physical_mem_block.flags],eax popad ret .addblock: call Insert_Block inc dword [num_physical_mem_blocks] mov eax,[esi+physical_mem_block.start] mov [esp+28],eax mov ecx,[0x3010] mov ecx,[ecx+0x4] mov [esi+physical_mem_block.flags],ecx mov ecx,[esi+physical_mem_block.size] mov [esi+physical_mem_block.size],ebx sub ecx,ebx mov [esi+physical_mem_block.sizeof+physical_mem_block.size],ecx add ebx,[esi+physical_mem_block.start] mov [esi+physical_mem_block.sizeof+physical_mem_block.start],ebx mov dword [esi+physical_mem_block.sizeof+physical_mem_block.flags],0 popad ret Free_Physical_Block: ;input: ; eax - address ;output: ; none pushad test eax,eax jz .ret mov ebx,eax xor eax,eax mov esi,physical_mem_blocks .loop: cmp ebx,[esi+physical_mem_block.start] jz .endloop inc eax add esi,physical_mem_block.sizeof cmp eax,[num_physical_mem_blocks] jl .loop jmp .ret .endloop: mov dword [esi+physical_mem_block.flags],0 test eax,eax jz .no_union_previous cmp dword [esi-physical_mem_block.sizeof+physical_mem_block.flags],0 jnz .no_union_previous mov ebx,[esi-physical_mem_block.sizeof+physical_mem_block.start] add ebx,[esi-physical_mem_block.sizeof+physical_mem_block.size] cmp ebx,[esi+physical_mem_block.start] jnz .no_union_previous mov ebx,[esi+physical_mem_block.size] add [esi-physical_mem_block.sizeof+physical_mem_block.size],ebx call Delete_Block dec eax dec [num_physical_mem_blocks] .no_union_previous: inc eax cmp eax,[num_physical_mem_blocks] jge .no_union_next cmp dword [esi+physical_mem_block.sizeof+physical_mem_block.flags],0 jnz .no_union_next mov ebx,[esi+physical_mem_block.start] add ebx,[esi+physical_mem_block.size] cmp ebx,[esi+physical_mem_block.sizeof+physical_mem_block.start] jnz .no_union_next mov ebx,[esi+physical_mem_block.sizeof+physical_mem_block.size] add [esi+physical_mem_block.size],ebx call Delete_Block dec [num_physical_mem_blocks] .no_union_next: .ret: popad ret sys_allocate_physical_block: ;eax - subfunction number mov eax,ebx call Allocate_Physical_Block mov [esp+36],eax ret sys_free_physical_block: ;eax - subfunction number mov eax,ebx call Free_Physical_Block ret sys_set_buffer: add ecx,std_application_base_address isys_set_buffer: ;for using in kernel ;eax - subfunction number ;ebx - physical address ;ecx - buffer start ;edx - buffer size lea edi,[ebx+second_base_address] mov esi,ecx mov ecx,edx rep movsb ret sys_get_buffer: add ecx,std_application_base_address isys_get_buffer: ;for using in kernel ;eax - subfunction number ;ebx - physical address ;ecx - buffer start ;edx - buffer size mov edi,ecx lea esi,[ebx+second_base_address] mov ecx,edx rep movsb ret sys_internal_services: cmp eax,4 jle sys_sheduler cmp eax,5 jz sys_allocate_physical_block cmp eax,6 jz sys_free_physical_block cmp eax,7 jz sys_set_buffer cmp eax,8 jz sys_get_buffer ret