Added kfree function

Ryand1234 · May 17, 2024 · 96995a1 · 96995a1
1 parent 5957f07
commit 96995a1
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Showing 4 changed files with 27 additions and 9 deletions.
diff --git a/kernel/arch/i386/linker.ld b/kernel/arch/i386/linker.ld
@@ -46,7 +46,7 @@ SECTIONS
 	    }
 	 .page_tables : {
         	__page_tables_start = .;
-	        . += 4096 * 4;
+	        . += 4096 * 1;
     	}
 
 	/* The compiler may produce other sections, put them in the proper place in

diff --git a/kernel/arch/i386/tty.c b/kernel/arch/i386/tty.c
@@ -7,7 +7,7 @@
 #include "vga.h"
 
 static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
+static const size_t VGA_HEIGHT = 100;
 static uint16_t* const VGA_MEMORY = (uint16_t*) 0xB8000;
 
 static size_t terminal_row;

diff --git a/kernel/kernel/kernel.c b/kernel/kernel/kernel.c
@@ -16,6 +16,11 @@ void kernel_main(void) {
 
     char* test = (char*) kmalloc(20);
     printf("Memory Address %d\n", test);
+    char* test1 = (char*) kmalloc(50);
+    printf("Memory Address for test1: %d\n", test1);
+    kfree(test);
+    char* test2= (char*) kmalloc(20);
+    printf("Memory Address for test2: %d\n", test2);
     divide_by_zero();
     printf("DONE");
 }

diff --git a/kernel/mmu/alloc.c b/kernel/mmu/alloc.c
@@ -3,17 +3,30 @@
 #include<stdint.h>
 void kfree(void  *v_addr)
 {
-	printf("KFREEEEEEEE\n");
+//	printf("KFREEEEEEEE\n");
+	if(v_addr == (void*)0)
+		return ;
+
+	struct kmalloc_header *chunk, *other;
+
+	chunk = (struct kmalloc_header*) ((uint32_t)v_addr - sizeof(struct kmalloc_header));
+
+	//printf("FREE CHUNK: %d, %d, %d\n", chunk, chunk->size, chunk->used);
+
+	chunk->used = 0;
+
+	kmalloc_used -= chunk->size;
+	while((other = (struct kmalloc_header*)((char*)chunk + chunk->size))  && other < (struct kmalloc_header*) kern_heap && other->used == 0)
+	{
+		chunk->size = chunk->size + other->size;
+	}
 
 }
 void *ksbrk(uint16_t n)
 {
-	printf("BREakkkkkk\n");
-
 	struct kmalloc_header* chunk;
 	char *p_addr;
 	uint32_t i;
-	printf("KSBRK: N: %d\n", n);
 
 	if((kern_heap + (n*PAGESIZE)) > (char*) KERN_HEAP_LIM) {
 		printf("PANIC ksbrk(): no memory left\n");
@@ -62,10 +75,10 @@ void *ksbrk(uint16_t n)
 				return 0;
 			}
 			chunk = (struct kmalloc_header*) ((char*)chunk + chunk->size);
-			if(chunk == (struct kmalloc_header*) kern_heap)
+		//	printf("CHUNK:%d,  %d, %d, HEAP: %d\n", chunk->size, chunk->used, chunk, (struct kmalloc_header*)kern_heap);
+			if(chunk == (struct kmalloc_header*) kern_heap || ((struct kmalloc_header*) kern_heap - chunk) < realsize)
 			{
-				chunk = (ksbrk((realsize/PAGESIZE)+1));
-			       	if((int)chunk < 0)
+				if((int)(ksbrk((realsize/PAGESIZE)+1)) < 0)
 				{
 					printf("No memory left %d, heap: %d", chunk, kern_heap);
 					asm("hlt");