From 8316c9f6aeeb977eaee7a442f66d071a3e1cd617 Mon Sep 17 00:00:00 2001
From: Imbus <>
Date: Sat, 6 Sep 2025 02:40:05 +0200
Subject: [PATCH] Remove original kalloc free-list memory allocator entirely
 for now

---
 Makefile      |  1 -
 kern/kalloc.c | 77 ---------------------------------------------------
 kern/kalloc.h | 33 ----------------------
 kern/start.c  |  7 +++--
 4 files changed, 5 insertions(+), 113 deletions(-)
 delete mode 100644 kern/kalloc.c
 delete mode 100644 kern/kalloc.h

diff --git a/Makefile b/Makefile
index cc4c6a3..3fbba85 100644
--- a/Makefile
+++ b/Makefile
@@ -55,7 +55,6 @@ quickstart:
 KERNEL_OBJ := \
 	kern/entry.o \
 	kern/start.o \
-	kern/kalloc.o \
 	kern/libkern/string.o \
 	kern/libkern/proc.o \
 	kern/libkern/uart.o \
diff --git a/kern/kalloc.c b/kern/kalloc.c
deleted file mode 100644
index dead607..0000000
--- a/kern/kalloc.c
+++ /dev/null
@@ -1,77 +0,0 @@
-#include <kalloc.h>
-#include <memory.h>
-#include <panic.h>
-#include <riscv.h>
-#include <spinlock.h>
-#include <stdint.h>
-#include <string.h>
-
-// Physical memory allocator, for user processes,
-// kernel stacks, page-table pages,
-// and pipe buffers. Allocates whole 4096-byte pages.
-
-/** Free list of physical pages. */
-void freerange(void *physaddr_start, void *physaddr_end);
-
-/** First address after kernel. Provided kernel.ld */
-extern char kernel_end[];
-
-/** A run is a node in the free list. */
-struct Run {
-    struct Run *next;
-};
-
-/** Kernel memory allocator. */
-struct {
-    spinlock_t  lock;
-    struct Run *freelist;
-} kmem;
-
-void kalloc_init() {
-    spinlock_init(&kmem.lock);
-    freerange(kernel_end, (void *)PHYSTOP);
-}
-
-void freerange(void *physaddr_start, void *physaddr_end) {
-    char *p;
-    p = (char *)PGROUNDUP((u64)physaddr_start);
-    for (; p + PGSIZE <= (char *)physaddr_end; p += PGSIZE) kfree(p);
-}
-
-void kfree(void *pa) {
-    struct Run *r;
-
-    // Assert that page is a ligned to a page boundary and that its correctly
-    // sized
-    if (((u64)pa % PGSIZE) != 0 || (char *)pa < kernel_end || (u64)pa >= PHYSTOP)
-        PANIC("kfree");
-
-    // TODO: Kconfig this
-    // Fill with junk to catch dangling refs.
-    memset(pa, 1, PGSIZE);
-
-    r = (struct Run *)pa;
-
-    spin_lock(&kmem.lock);
-    r->next = kmem.freelist;
-    kmem.freelist = r;
-    spin_unlock(&kmem.lock);
-}
-
-void *kalloc(void) {
-    struct Run *r;
-
-    spin_lock(&kmem.lock);
-
-    r = kmem.freelist;
-
-    if (r)
-        kmem.freelist = r->next;
-
-    spin_unlock(&kmem.lock);
-
-    if (r)
-        memset((char *)r, 5, PGSIZE); // fill with junk
-
-    return (void *)r;
-}
diff --git a/kern/kalloc.h b/kern/kalloc.h
deleted file mode 100644
index 592d814..0000000
--- a/kern/kalloc.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef KALLOC_KERNEL_H
-#define KALLOC_KERNEL_H
-
-/**
- * Kernel memory allocator
- *
- * Allocate one 4096-byte page of physical memory.
- * Returns a pointer that the kernel can use.
- * Returns 0 if the memory cannot be allocated.
- * See: kalloc.c
- */
-void *kalloc(void);
-
-/**
- * Kernel memory allocator
- *
- * Free the page of physical memory pointed at by pa,
- * which normally should have been returned by a
- * call to kalloc().  (The exception is when
- * initializing the allocator; see kinit above.)
- * See: kalloc.c
- */
-void kfree(void *);
-
-/**
- * Initialize kernel memory allocator
- *
- * Called by main() on the way to the kernel's main loop.
- * See: kalloc.c
- */
-void kalloc_init(void);
-
-#endif // KALLOC_KERNEL_H
diff --git a/kern/start.c b/kern/start.c
index 0e4b264..c892765 100644
--- a/kern/start.c
+++ b/kern/start.c
@@ -1,6 +1,7 @@
+#include <assert.h>
 #include <banner.h>
+#include <buddy.h>
 #include <config.h>
-#include <kalloc.h>
 #include <memory.h>
 #include <panic.h>
 #include <proc.h>
@@ -8,6 +9,7 @@
 #include <spinlock.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <string.h>
 #include <uart.h>
 
 /**
@@ -39,7 +41,8 @@ void start() {
 
     if (id == 0) {
         /* Here we will do a bunch of initialization steps */
-        kalloc_init();
+        memory_sweep(heap_start, heap_end);
+        buddy_init(heap_start, heap_end);
         spinlock_init(&sl);
         for (int i = 0; i < banner_len; i++) uart_putc(banner[i]);
         __sync_synchronize();