.o's to .so

2022-12-06 00:29:05 +03:00
parent 1eeb7d4eac
commit b6dfb0ac29
18 changed files with 155 additions and 72 deletions
@@ -0,0 +1,98 @@
+format ELF
+public _add as 'heap.add'
+public del  as 'heap.del'
+
+include '../include/macros.inc'
+extrn exit
+
+section '.bss' writeable
+_heap:
+    db 0xB  ; flag
+    dd 4    ; size
+    dd 4096 ; available memory
+    
+    rd 4096
+
+section '.text' executable
+_add:
+    prelude
+
+    mov ecx, [ebp+2*4]  ; size
+    mov eax, _heap
+    xor edx, edx
+
+    .loop:
+        cmp [eax], byte 0
+        je .empty
+
+        mov bl, [eax]
+        bt  bx, 0
+        jc .busy
+
+        inc eax
+        cmp edx, 0
+        jne @f
+            mov edx, eax
+        @@:
+        cmp ecx, [eax]
+        jl .more
+        je .equal
+        ; less
+            sub ecx, [eax]
+            add eax, [eax]
+            add eax, 4
+            jmp .loop
+        .equal:
+            mov [edx], byte 9
+            mov ebx, [ebp+2*4]
+            mov [edx+1], ebx
+            add edx, 5
+            mov [ebp+2*4], edx
+            postlude
+            ret
+        .more:
+            mov ebx, edx
+            add ebx, [ebp+2*4]
+            mov [ebx], byte 9
+            inc ebx
+            mov eax, [eax]
+            sub eax, ecx
+            mov [ebx], eax
+            
+            add ebx, [ebp+2*4]
+            mov [edx-1], byte 9
+            mov edx, ebx
+
+            add edx, 5
+            mov [ebp+2*4], edx
+            postlude
+            ret
+        
+        .empty:
+            cmp edx, 0
+            jne @f
+                mov edx, eax
+            @@:
+            je @f
+                dec edx
+            @@:
+            jmp .equal
+
+        .busy:
+        xor edx, edx
+        inc eax
+        add eax, [eax]
+        add eax, 4
+
+        jmp .loop
+
+del:
+    push eax
+    mov eax, [esp+4*2]
+    sub eax, 5
+    and byte [eax], 254
+    mov eax, [esp+4]
+    mov [esp+4*2], eax
+    pop eax
+    add esp, 4
+    ret