131 lines
2.2 KiB
PHP
131 lines
2.2 KiB
PHP
;; File: pmm.inc
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;;
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;; Our PMM is just a linked list of page-aligned size blocks.
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;;
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;; > ┌─────┐ ┌─────┐
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;; > │size │ ┌──►│size │
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;; > │next ├──┘ │next ├────► 0
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;; > └─────┘ └─────┘
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;;
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;; Macro: PAGE_ALIGN_UP reg
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macro PAGE_ALIGN_UP reg {
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add reg, PAGE_SIZE - 1
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and reg, -PAGE_SIZE
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}
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;; Macro: PAGE_ALIGN_DOWN reg
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macro PAGE_ALIGN_DOWN reg {
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and reg, -PAGE_SIZE
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}
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;; Struc: PMMFreeRange
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struc PMMFreeRange {
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.size dd ?
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.next dd ?
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}
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DEFN PMMFreeRange
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;; Function: _pmm_map_temp_page
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;;
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_pmm_map_temp_page:
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ret
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_pmm_unmap_temp_page:
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ret
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_pmm_init_region:
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push ebp
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mov ebp, esp
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push eax
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call _pmm_map_temp_page
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pop eax
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xor ecx, ecx
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mov [MM_VIRT_TEMP], edx
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mov [MM_VIRT_TEMP + PMMFreeRange.next], ecx
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mov ecx, [pPMMFreeListHead]
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or ecx, ecx
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jz @f
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mov [MM_VIRT_TEMP + PMMFreeRange.next], ecx
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@@:
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mov [pPMMFreeListHead], eax
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call _pmm_unmap_temp_page
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leave
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ret
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;; Function: pmm_alloc
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;;
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;; In:
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;; EAX - size in page
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;;
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;; Out:
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;; EAX - first page physical address, 0 on error
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pmm_alloc:
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ret
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;; Function: pmm_alloc_page
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;;
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;; Out:
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;; EAX - page physical address, 0 on error
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pmm_alloc_page:
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mov eax, 1
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call pmm_alloc
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ret
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;; Function: pmm_free
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;;
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;; In:
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;; EAX - Start
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;; EDX - End
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pmm_free:
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ret
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;; Function: _pmm_init_region
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;;
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;; Add new memory region to the linked list.
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;;
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;; In:
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;; EAX - Start
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;; EDX - End
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;;
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;; Function: pmm_init
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;;
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;; Out:
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;; EAX - return -1 on error
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pmm_init:
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mov esi, szMsgMmInit
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call klog
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mov eax, kend
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PAGE_ALIGN_UP eax
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mov edx, 0x400000
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sub edx, eax
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jle @f
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cmp edx, PAGE_SIZE
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jle @f
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mov edx, 0x400000
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call _pmm_init_region
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@@:
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mov eax, 0x800000
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mov edx, [stBootInfo.high_mem]
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PAGE_ALIGN_DOWN edx
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call _pmm_init_region
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xor eax, eax ; TODO: check if enough memory and so on
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ret
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;; Variable: pPMMFreeListHead
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;; Hold first free list entry physical address
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pPMMFreeListHead dd 0
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szMsgPmmInit db "PMM: initialize", 0
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szMsgPmmFreeRange db "PMM: add free memory region %x - %x", 0
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szErrorNoMemLeft db "Error(PMM): no free memory left", 0
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