diff --git a/src/core/osloader.c b/src/core/osloader.c
index c952a25f..4e1860ce 100644
--- a/src/core/osloader.c
+++ b/src/core/osloader.c
@@ -29,351 +29,71 @@ Modifications: Ken Yap (for Etherboot/16)
  * your option) any later version.
  */
 
-#include "etherboot.h"
+#include "io.h"
+#include "heap.h"
 #include "memsizes.h"
 
-#ifdef KEEP_IT_REAL
+/* Linker symbols */
+extern char _text[];
+extern char _end[];
 
-#warning "All download mechanisms are broken under KEEP_IT_REAL"
-
-os_download_t probe_image(unsigned char *data, unsigned int len) {
-	return 0;
-}
-
-int load_block(unsigned char *data, unsigned int block, unsigned int len, int eof) {
-	return 1;
-}
-
-#else /* KEEP_IT_REAL */
-
-
-struct os_entry_regs os_regs;
-
-static struct ebinfo		loaderinfo = {
-	VERSION_MAJOR, VERSION_MINOR,
-	0
-};
-
-#define LOAD_DEBUG 0
-
-static int prep_segment(unsigned long start, unsigned long mid, unsigned long end,
-	unsigned long istart, unsigned long iend);
-static unsigned long find_segment(unsigned long size, unsigned long align);
-static sector_t dead_download ( unsigned char *data, unsigned int len, int eof);
-static void done(int do_cleanup);
-
-#if defined(IMAGE_FREEBSD) && defined(ELF_IMAGE)
-static void elf_freebsd_probe(void);
-static void elf_freebsd_fixup_segment(void);
-static void elf_freebsd_find_segment_end(void);
-static int elf_freebsd_debug_loader(unsigned int offset);
-static void elf_freebsd_boot(unsigned long entry);
-#else
-#define elf_freebsd_probe() do {} while(0)
-#define elf_freebsd_fixup_segment()  do {} while(0)
-#define elf_freebsd_find_segment_end() do {} while(0)
-#define elf_freebsd_debug_loader(off) (0)
-#define elf_freebsd_boot(entry) do {} while(0)
-#endif
-#if defined(IMAGE_FREEBSD) && defined(AOUT_IMAGE)
-static void aout_freebsd_probe(void);
-static void aout_freebsd_boot(void);
-#else
-#define aout_freebsd_probe() do {} while(0)
-#define aout_freebsd_boot() do {} while(0)
-#endif
-
-/**************************************************************************
-dead_download - Restart etherboot if probe image fails
-**************************************************************************/
-static sector_t dead_download ( unsigned char *data __unused, unsigned int len __unused, int eof __unused) {
-        longjmp(restart_etherboot, -2);
-}
-
-#ifdef	IMAGE_MULTIBOOT
-#include "../arch/i386/core/multiboot_loader.c"
-#else
-#define multiboot_probe(data, len) do {} while(0)
-#define multiboot_boot(entry) do {} while(0)
-#endif
-
-
-#ifdef WINCE_IMAGE
-#include "../arch/i386/core/wince_loader.c"
-#endif
-
-#ifdef AOUT_IMAGE
-#include "../arch/i386/core/aout_loader.c"
-#endif
-
-#ifdef TAGGED_IMAGE
-#include "../arch/i386/core/tagged_loader.c"
-#endif
-
-#if defined(ELF_IMAGE) || defined(ELF64_IMAGE)
-#include "elf_loader.c"
-#endif
-
-#if defined(COFF_IMAGE) 
-#include "../arch/e1/core/coff_loader.c"
-#endif
-
-#ifdef IMAGE_FREEBSD
-#include "../arch/i386/core/freebsd_loader.c"
-#endif
-
-#ifdef PXE_IMAGE
-#include "../arch/i386/core/pxe_loader.c"
-#endif
-
-#ifdef RAW_IMAGE
-#include "../arch/armnommu/core/raw_loader.c"
-#endif
-
-static void done(int do_cleanup)
-{
-#ifdef	SIZEINDICATOR
-	printf("K ");
-#endif
-	printf("done\n");
-	/* We may not want to do the cleanup: when booting a PXE
-	 * image, for example, we need to leave the network card
-	 * enabled, and it helps debugging if the serial console
-	 * remains enabled.  The call the cleanup() will be triggered
-	 * when the PXE stack is shut down.
-	 */
-	if ( do_cleanup ) {
-		cleanup();
-		/* arch_on_exit(0); */
-	}
-}
-
-static int prep_segment(unsigned long start, unsigned long mid, unsigned long end,
-	unsigned long istart __unused, unsigned long iend __unused)
-{
+int prep_segment ( physaddr_t start, physaddr_t mid, physaddr_t end ) {
 	unsigned fit, i;
 
-#if LOAD_DEBUG
-	printf ( "\nAbout to prepare segment [%lX,%lX)\n", start, end );
-	sleep ( 3 );
-#endif
+	DBG ( "OSLOADER preparing segment [%lX,%lX)\n", start, end );
 
-	if (mid > end) {
-		printf("filesz > memsz\n");
+	if ( mid > end ) {
+		DBG ( "OSLOADER got filesz > memsz\n" );
 		return 0;
 	}
-	if ((end > virt_to_phys(_text)) && 
-		(start < virt_to_phys(_end))) {
-		printf("segment [%lX, %lX) overlaps etherboot [%lX, %lX)\n",
-			start, end,
-			virt_to_phys(_text), virt_to_phys(_end)
-			);
+
+	/* Check for overlap with Etherboot runtime image */
+	if ( ( end > virt_to_phys ( _text ) ) && 
+	     ( start < virt_to_phys ( _end ) ) ) {
+		DBG ( "OSLOADER got segment [%lX, %lX) "
+		      "overlapping etherboot [%lX, %lX)\n",
+		      start, end,
+		      virt_to_phys ( _text ), virt_to_phys ( _end ) );
 		return 0;
 	}
-	if ((end > heap_ptr) && (start < heap_bot)) {
-		printf("segment [%lX, %lX) overlaps heap [%lX, %lX)\n",
-			start, end,
-			heap_ptr, heap_bot
-			);
+
+	/* 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++) {
+	for ( i = 0 ; i < meminfo.map_count ; i++ ) {
 		unsigned long long r_start, r_end;
+
 		if (meminfo.map[i].type != E820_RAM)
 			continue;
+
 		r_start = meminfo.map[i].addr;
 		r_end = r_start + meminfo.map[i].size;
-		if ((start >= r_start) && (end <= r_end)) {
+		if ( ( start >= r_start ) && ( end <= r_end ) ) {
 			fit = 1;
 			break;
 		}
 	}
-	if (!fit) {
-		printf("\nsegment [%lX,%lX) does not fit in any memory region\n",
-			start, end);
-#if LOAD_DEBUG
-		printf("Memory regions(%d):\n", meminfo.map_count);
-		for(i = 0; i < meminfo.map_count; i++) {
-			unsigned long long r_start, r_end;
-			if (meminfo.map[i].type != E820_RAM)
-				continue;
-			r_start = meminfo.map[i].addr;
-			r_end = r_start + meminfo.map[i].size;
-			printf("[%X%X, %X%X) type %d\n", 
-				(unsigned long)(r_start >> 32),
-				(unsigned long)r_start,
-				(unsigned long)(r_end >> 32),
-				(unsigned long)r_end,
-				meminfo.map[i].type);
-		}
-#endif
+	if ( ! fit ) {
+		DBG ( "OSLOADER got segment [%lX,%lX) "
+		      "which does not fit in any memory region\n",
+			start, end );
 		return 0;
 	}
-#if LOAD_DEBUG
-	/* Zap the whole lot.  Do this so that if we're treading on
-	 * anything, it shows up now, when the debug message is
-	 * visible, rather than when we're partway through downloading
-	 * the file.
-	 *
-	 * If you see an entire screen full of exclamation marks, then
-	 * you've almost certainly written all over the display RAM.
-	 * This is likely to happen if the status of the A20 line gets
-	 * screwed up.  Of course, if this happens, it's a good bet
-	 * that you've also trashed the whole of low memory, so expect
-	 * interesting things to happen...
-	 */
-	memset(phys_to_virt(start), '!', mid - start);
-#endif
+
 	/* Zero the bss */
-	if (end > mid) {
-		memset(phys_to_virt(mid), 0, end - mid);
-	}
-	return 1;
-}
+	memset ( phys_to_virt ( mid ), 0, end - mid );
 
-static unsigned long find_segment(unsigned long size, unsigned long align)
-{
-	unsigned i;
-	/* Verify I have a power of 2 alignment */
-	if (align & (align - 1)) {
-		return ULONG_MAX;
-	}
-	for(i = 0; i < meminfo.map_count; i++) {
-		unsigned long r_start, r_end;
-		if (meminfo.map[i].type != E820_RAM)
-			continue;
-		if ((meminfo.map[i].addr + meminfo.map[i].size) > ULONG_MAX) {
-			continue;
-		}
-		r_start = meminfo.map[i].addr;
-		r_end = r_start + meminfo.map[i].size;
-		/* Don't allow the segment to overlap etherboot */
-		if ((r_end > virt_to_phys(_text)) && (r_start < virt_to_phys(_text))) {
-			r_end = virt_to_phys(_text);
-		}
-		if ((r_start > virt_to_phys(_text)) && (r_start < virt_to_phys(_end))) {
-			r_start = virt_to_phys(_end);
-		}
-		/* Don't allow the segment to overlap the heap */
-		if ((r_end > heap_ptr) && (r_start < heap_ptr)) {
-			r_end = heap_ptr;
-		}
-		if ((r_start > heap_ptr) && (r_start < heap_bot)) {
-			r_start = heap_ptr;
-		}
-		r_start = (r_start + align - 1) & ~(align - 1);
-		if ((r_end >= r_start) && ((r_end - r_start) >= size)) {
-			return r_start;
-		}
-	}
-	/* I did not find anything :( */
-	return ULONG_MAX;
-}
-
-/**************************************************************************
-PROBE_IMAGE - Detect image file type
-**************************************************************************/
-os_download_t probe_image(unsigned char *data, unsigned int len)
-{
-	os_download_t os_download = 0;
-
-#ifdef AOUT_IMAGE
-	if (!os_download) os_download = aout_probe(data, len);
-#endif
-#ifdef ELF_IMAGE
-	if (!os_download) os_download = elf32_probe(data, len);
-#endif
-#ifdef ELF64_IMAGE
-	if (!os_download) os_download = elf64_probe(data, len);
-#endif
-#ifdef COFF_IMAGE
-    if (!os_download) os_download = coff_probe(data, len);
-#endif
-#ifdef WINCE_IMAGE
-	if (!os_download) os_download = wince_probe(data, len);
-#endif
-#ifdef TAGGED_IMAGE
-	if (!os_download) os_download = tagged_probe(data, len);
-#endif
-/* PXE_IMAGE must always be last */
-#ifdef PXE_IMAGE
-	if (!os_download) os_download = pxe_probe(data, len);
-#endif
-#ifdef RAW_IMAGE
-	if (!os_download) os_download = raw_probe(data, len);
-#endif
-
-	return os_download;
-}
-
-/**************************************************************************
-LOAD_BLOCK - Try to load file
-**************************************************************************/
-int load_block(unsigned char *data, unsigned int block, unsigned int len, int eof)
-{
-	static os_download_t os_download;
-	static sector_t skip_sectors;
-	static unsigned int skip_bytes;
-#ifdef	SIZEINDICATOR
-	static int rlen = 0;
-
-	if (block == 1)
-	{
-		rlen=len;
-		printf("XXXX");
-	}
-	if (!(block % 4) || eof) {
-		int size;
-		size = ((block-1) * rlen + len) / 1024;
-
-		putchar('\b');
-		putchar('\b');
-		putchar('\b');
-		putchar('\b');
-
-		putchar('0' + (size/1000)%10);
-		putchar('0' + (size/100)%10);
-		putchar('0' + (size/10)%10);
-		putchar('0' + (size/1)%10);
-	}
-#else
-	putchar ( '.' );
-#endif
-	if (block == 1)
-	{
-		skip_sectors = 0;
-		skip_bytes = 0;
-		os_download = probe_image(data, len);
-		if (!os_download) {
-			printf("error: not a valid image\n");
-#if 0
-			printf("block: %d len: %d\n", block, len);
-			printf("%hhx %hhx %hhx %hhx %hhx %hhx %hhx %hhx %hhx\n",
-				data[0], data[1], data[2], data[3],
-				data[4], data[5], data[6], data[7]);
-#endif
-			return 0;
-		}
-	} /* end of block zero processing */
-
-	/* Either len is greater or the skip is greater */
-	if ((skip_sectors > (len >> 9)) ||
-		((skip_sectors == (len >> 9)) && (skip_bytes >= (len & 0x1ff)))) {
-		/* If I don't have enough bytes borrow them from skip_sectors */
-		if (skip_bytes < len) {
-			skip_sectors -= (len - skip_bytes + 511) >> 9;
-			skip_bytes += (len - skip_bytes + 511) & ~0x1ff;
-		}
-		skip_bytes -= len;
-	}
-	else {
-		len -= (skip_sectors << 9) + skip_bytes;
-		data += (skip_sectors << 9) + skip_bytes;
-	}
-	skip_sectors = os_download(data, len, eof);
-	skip_bytes = 0;
-	
 	return 1;
 }
 
@@ -382,5 +102,3 @@ int load_block(unsigned char *data, unsigned int block, unsigned int len, int eo
  *  c-basic-offset: 8
  * End:
  */
-
-#endif /* KEEP_IT_REAL */