Tear out old heap code, replace with code that simply allocates memory

for use by malloc().

This breaks the image-loading code (which previously used the heap to
allocate the buffer for downloading the image), but that's not a major
concern since I'm going to tear out all the image formats within the next
couple of days anyway.  Byebye, NBI!  :)

src/core/heap.c

@@ -1,208 +1,27 @@
-#include "etherboot.h"
-#include <gpxe/init.h>
-#include "memsizes.h"
-#include <assert.h>
-#include "heap.h"
+#include <malloc.h>
+#include <gpxe/heap.h>
 
-struct heap_block {
-	size_t size;
-	unsigned int align;
-	char data[0];
-};
-
-/* Linker symbols */
-extern char _text[];
-extern char _end[];
-
-static physaddr_t heap_start;
-
-/*
- * Find the largest contiguous area of memory that I can use for the
- * heap.
- *
- */
-static void init_heap ( void ) {
-	unsigned int i;
-	physaddr_t eb_start, eb_end;
-	physaddr_t size;
-
-	size = 0;
-	
-	/* Region occupied by Etherboot */
-	eb_start = virt_to_phys ( _text );
-	eb_end = virt_to_phys ( _end );
-
-	for ( i = 0 ; i < meminfo.map_count ; i++ ) {
-		physaddr_t r_start, r_end, r_size;
-		physaddr_t pre_eb, post_eb;
-
-		/* Get start and end addresses of the region */
-		if ( meminfo.map[i].type != E820_RAM )
-			continue;
-		if ( meminfo.map[i].addr > ULONG_MAX )
-			continue;
-		r_start = meminfo.map[i].addr;
-		if ( r_start + meminfo.map[i].size > ULONG_MAX ) {
-			r_end = ULONG_MAX;
-		} else {
-			r_end = r_start + meminfo.map[i].size;
-		}
-		
-		/* Avoid overlap with Etherboot.  When Etherboot is
-		 * completely contained within the region, choose the
-		 * larger of the two remaining portions.
-		 */
-		if ( ( eb_start < r_end ) && ( eb_end > r_start ) ) {
-			pre_eb = ( eb_start > r_start ) ?
-				( eb_start - r_start ) : 0;
-			post_eb = ( r_end > eb_end ) ?
-				( r_end - eb_end ) : 0;
-			if ( pre_eb > post_eb ) {
-				r_end = eb_start;
-			} else {
-				r_start = eb_end;
-			}
-		}
-
-		/* Use the biggest region.  Where two regions are the
-		 * same size, use the later region.  (Provided that
-		 * the memory map is laid out in a sensible order,
-		 * this should give us the higher region.)
-		 */
-		r_size = r_end - r_start;
-		if ( r_size >= size ) {
-			heap_start = r_start;
-			heap_end = r_end;
-			size = r_size;
-		}
-	}
-
-	assert ( size != 0 );
-	DBG ( "HEAP using region [%x,%x)\n", heap_start, heap_end );
-	heap_ptr = heap_end;
-}
-
-/*
- * Allocate a block from the heap.
- *
- */
-static inline physaddr_t block_alloc_addr ( physaddr_t heap_ptr,
-					    size_t size, unsigned int align ) {
-	return ( ( ( heap_ptr - size ) & ~( align - 1 ) )
-		 - sizeof ( struct heap_block ) );
-}
-
-void * emalloc ( size_t size, unsigned int align ) {
-	struct heap_block *block;
-	physaddr_t addr;
-	
-	assert ( ( align & ( align - 1 ) ) == 0 );
-
-	addr = block_alloc_addr ( heap_ptr, size, align );
-	if ( addr < heap_start ) {
-		DBG ( "HEAP no space for %x bytes (alignment %d) in [%x,%x)\n",
-		      size, align, heap_start, heap_ptr );
-		return NULL;
-	}
-
-	block = phys_to_virt ( addr );
-	block->size = ( heap_ptr - addr );
-	block->align = align;
-	DBG ( "HEAP allocated %x bytes (alignment %d) at %x [%x,%x)\n",
-	      size, align, virt_to_phys ( block->data ), addr, heap_ptr );
-	heap_ptr = addr;
-	return block->data;
-}
-
-/*
- * Allocate all remaining space on the heap
+/**
+ * @file
  *
- */
-void * emalloc_all ( size_t *size ) {
-	*size = heap_ptr - heap_start - sizeof ( struct heap_block );
-	return emalloc ( *size, sizeof ( void * ) );
-}
-
-/*
- * Free a heap block
+ * Heap
  *
  */
-static inline physaddr_t block_free_addr ( size_t size ) {
-	return heap_ptr + size;
-}
-
-void efree ( void *ptr ) {
-	struct heap_block *block;
-
-	assert ( ptr == phys_to_virt ( heap_ptr + sizeof ( size_t ) ) );
-	
-	block = ( struct heap_block * )
-		( ptr - offsetof ( struct heap_block, data ) );
-	heap_ptr = block_free_addr ( block->size );
-
-	DBG ( "HEAP freed %x [%x,%x)\n", virt_to_phys ( ptr ),
-	      virt_to_phys ( block ), heap_ptr );
 
-	assert ( heap_ptr <= heap_end );
-}
-
-/*
- * Free all allocated heap blocks
+/**
+ * Heap size
  *
+ * Currently fixed at 48kB.
  */
-void efree_all ( void ) {
-	DBG ( "HEAP discarding allocated blocks in [%x,%x)\n",
-	      heap_ptr, heap_end );
+#define HEAP_SIZE ( 48 * 1024 )
 
-	heap_ptr = heap_end;
-}
+/** The heap itself */
+char heap[HEAP_SIZE] __attribute__ (( aligned ( __alignof__(void *) )));
 
-/*
- * Resize a heap block
+/**
+ * Initialise the heap
  *
  */
-void * erealloc ( void *ptr, size_t size ) {
-	struct heap_block *old_block;
-	size_t old_size;
-	unsigned int old_align;
-	physaddr_t new_addr;
-	size_t move_size;
-	
-	/* Get descriptor of the old block */
-	old_block = ( struct heap_block * )
-		( ptr - offsetof ( struct heap_block, data ) );
-	old_size = old_block->size;
-	old_align = old_block->align;
-
-	/* Check that allocation is going to succeed */
-	new_addr = block_alloc_addr ( block_free_addr ( old_size ),
-				      size, old_align );
-	if ( new_addr < heap_start ) {
-		DBG ( "HEAP no space for %x bytes (alignment %d) in [%x,%x)\n",
-		      size, align, heap_start, block_free_addr ( old_size ) );
-		return NULL;
-	}
-
-	/* Free the old block */
-	efree ( ptr );
-
-	/* Move the data.  Do this *before* allocating the new block,
-	 * because the new block's descriptor may overwrite the old
-	 * block's data, if the new block is smaller than the old
-	 * block.
-	 */
-	move_size = size + sizeof ( struct heap_block );
-	if ( old_size < move_size )
-		move_size = old_size;
-	memmove ( phys_to_virt ( new_addr ), old_block, move_size );
-
-	/* Allocate the new block.  This must succeed, because we
-	 * already checked that there was sufficient space.
-	 */
-	ptr = emalloc ( size, old_align );
-	assert ( ptr != NULL );
-
-	return ptr;
+void init_heap ( void ) {
+	mpopulate ( heap, sizeof ( heap ) );
 }
-
-INIT_FN ( INIT_HEAP, init_heap, efree_all, NULL );

src/core/image.c

@@ -18,6 +18,8 @@ void print_images ( void ) {
 	}
 }
 
+#if 0
+
 /*
  * Identify the image format
  *
@@ -80,3 +82,5 @@ int autoload ( struct dev *dev, struct image **image, void **context ) {
  out:
 	return rc;
 }
+
+#endif

src/core/osloader.c

@@ -30,7 +30,6 @@ Modifications: Ken Yap (for Etherboot/16)
  */
 
 #include "io.h"
-#include "heap.h"
 #include "memsizes.h"
 
 /* Linker symbols */
@@ -57,18 +56,6 @@ int prep_segment ( physaddr_t start, physaddr_t mid, physaddr_t end ) {
 		return 0;
 	}
 
-	/* Check for overlap with used portion of heap.  Since the
-	 * heap code just finds the biggest available memory area, we
-	 * check only against the used heap area, rather than the
-	 * whole heap area.
-	 */
-	if ( ( end > heap_ptr ) && ( start < heap_end ) ) {
-		DBG ( "OSLOADER got segment [%lX, %lX) "
-		      "overlapping used heap [%lX, %lX)\n",
-		      start, end, heap_ptr, heap_end );
-		return 0;
-	}
-
 	/* Check that block fits entirely inside a single memory region */
 	fit = 0;
 	for ( i = 0 ; i < meminfo.map_count ; i++ ) {

src/include/gpxe/heap.h

@@ -0,0 +1,15 @@
+#ifndef _GPXE_HEAP_H
+#define _GPXE_HEAP_H
+
+/**
+ * @file
+ *
+ * Heap
+ *
+ */
+
+extern char heap[];
+
+extern void init_heap ( void );
+
+#endif /* _GPXE_HEAP_H */

src/include/heap.h

@@ -1,92 +0,0 @@
-#ifndef HEAP_H
-#define HEAP_H
-
-/*
- * Allocate a block with specified (physical) alignment
- *
- * "align" must be a power of 2.
- *
- * Note that "align" affects the alignment of the physical address,
- * not the virtual address.  This is almost certainly what you want.
- *
- */
-extern void * emalloc ( size_t size, unsigned int align );
-
-/*
- * Allocate all remaining space on the heap
- *
- */
-extern void * emalloc_all ( size_t *size );
-
-/*
- * Free a block.
- *
- * The caller must ensure that the block being freed is the last (most
- * recent) block allocated on the heap, otherwise heap corruption will
- * occur.
- *
- */
-extern void efree ( void *ptr );
-
-/*
- * Free all allocated blocks on the heap
- *
- */
-extern void efree_all ( void );
-
-/*
- * Resize a block.
- *
- * The caller must ensure that the block being resized is the last
- * (most recent) block allocated on the heap, otherwise heap
- * corruption will occur.
- *
- */
-extern void * erealloc ( void *ptr, size_t size );
-
-/*
- * Allocate, free, and resize blocks without caring about alignment
- *
- */
-static inline void * malloc ( size_t size ) {
-	return emalloc ( size, sizeof ( void * ) );
-}
-
-static inline void free ( void *ptr ) {
-	efree ( ptr );
-}
-
-static inline void * realloc ( void *ptr, size_t size ) {
-	return erealloc ( ptr, size );
-}
-
-/*
- * Legacy API calls
- *
- */
-static inline void * allot ( size_t size ) {
-	return emalloc ( size, sizeof ( void * ) );
-}
-
-static inline void forget ( void *ptr ) {
-	efree ( ptr );
-}
-
-static inline void * allot2 ( size_t size, uint32_t mask ) {
-	return emalloc ( size, mask + 1 );
-}
-
-static inline void forget2 ( void *ptr ) {
-	efree ( ptr );
-}
-
-/*
- * Heap markers.  osloader.c and other code may wish to know the heap
- * location, without necessarily wanting to drag in heap.o.  We
- * therefore declare these as shared (i.e. common) symbols.
- *
- */
-physaddr_t heap_ptr __asm__ ( "_shared_heap_ptr" );
-physaddr_t heap_end __asm__ ( "_shared_heap_end" );
-
-#endif /* HEAP_H */