diff options
Diffstat (limited to 'kalloc.c')
| -rw-r--r-- | kalloc.c | 22 |
1 files changed, 13 insertions, 9 deletions
@@ -17,17 +17,21 @@ struct { struct run *freelist; } kmem; +extern char end[]; // first address after kernel loaded from ELF file + // Initialize free list of physical pages. void -kinit(char *p, uint len) +kinit(void) { + char *p; + initlock(&kmem.lock, "kmem"); - char *p1 = (char*)PGROUNDUP((uint)p); - char *p2 = PGROUNDDOWN(p + len); - for( ; p1 < p2; p1 += 4096) - kfree(p1); + p = (char*)PGROUNDUP((uint)end); + for(; p + PGSIZE <= (char*)PHYSTOP; p += PGSIZE) + kfree(p); } +//PAGEBREAK: 21 // Free the page of physical memory pointed at by v, // which normally should have been returned by a // call to kalloc(). (The exception is when @@ -37,14 +41,14 @@ kfree(char *v) { struct run *r; - if(((uint) v) % PGSIZE || (uint)v < 1024*1024 || (uint)v >= PHYSTOP) + if((uint)v % PGSIZE || v < end || (uint)v >= PHYSTOP) panic("kfree"); // Fill with junk to catch dangling refs. memset(v, 1, PGSIZE); acquire(&kmem.lock); - r = (struct run *) v; + r = (struct run*)v; r->next = kmem.freelist; kmem.freelist = r; release(&kmem.lock); @@ -54,7 +58,7 @@ kfree(char *v) // Returns a pointer that the kernel can use. // Returns 0 if the memory cannot be allocated. char* -kalloc() +kalloc(void) { struct run *r; @@ -63,6 +67,6 @@ kalloc() if(r) kmem.freelist = r->next; release(&kmem.lock); - return (char*) r; + return (char*)r; } |