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diff --git a/util/alternatives/kmem.c b/util/alternatives/kmem.c
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+/**
+** @file kmem.c
+**
+** @author Warren R. Carithers
+** @author Kenneth Reek
+** @author 4003-506 class of 20013
+**
+** @brief	Functions to perform dynamic memory allocation in the OS.
+**
+** NOTE: these should NOT be called by user processes!
+**
+** This allocator functions as a simple "slab" allocator; it allows
+** allocation of either 4096-byte ("page") or 1024-byte ("slice")
+** chunks of memory from the free pool.  The free pool is initialized
+** using the memory map provided by the BIOS during the boot sequence,
+** and contains a series of blocks which are multiples of 4K bytes and
+** which are aligned at 4K boundaries; they are held in the free list
+** in order by base address.
+**
+** The "page" allocator allows allocation of one or more 4K blocks
+** at a time.  Requests are made for a specific number of 4K pages;
+** the allocator locates the first free list entry that contains at
+** least the requested amount of space.  If that entry is the exact
+** size requested, it is unlinked and returned; otherwise, the entry
+** is split into a chunk of the requested size and the remainder.
+** The chunk is returned, and the remainder replaces the original
+** block in the free list.  On deallocation, the block is inserted
+** at the appropriate place in the free list, and physically adjacent
+** blocks are coalesced into single, larger blocks.  If a multi-page
+** block is allocated, it should be deallocated one page at a time,
+** because there is no record of the size of the original allocation -
+** all we know is that it is N*4K bytes in length, so it's up to the
+** requesting code to figure this out.
+**
+** The "slice" allocator operates by taking blocks from the "page"
+** allocator and splitting them into four 1K slices, which it then
+** manages.  Requests are made for slices one at a time.  If the free
+** list contains an available slice, it is unlinked and returned;
+** otherwise, a page is requested from the page allocator, split into
+** slices, and the slices are added to the free list, after which the
+** first one is returned.  The slice free list is a simple linked list
+** of these 1K blocks; because they are all the same size, no ordering
+** is done on the free list, and no coalescing is performed.
+**
+*/
+
+#define KERNEL_SRC
+
+#include <common.h>
+
+// all other framework includes are next
+#include <lib.h>
+
+#include <x86/arch.h>
+#include <x86/bios.h>
+#include <bootstrap.h>
+#include <cio.h>
+
+#include <kmem.h>
+
+/*
+** PRIVATE DEFINITIONS
+*/
+
+// parameters related to word and block sizes
+
+#define WORD_SIZE           sizeof(int)
+#define LOG2_OF_WORD_SIZE   2
+
+#define LOG2_OF_PAGE_SIZE   12
+
+#define LOG2_OF_SLICE_SIZE  10
+
+// converters:  pages to bytes, bytes to pages
+
+#define P2B(x)   ((x) << LOG2_OF_PAGE_SIZE)
+#define B2P(x)   ((x) >> LOG2_OF_PAGE_SIZE)
+
+/*
+** Name:    adjacent
+**
+** Arguments:   addresses of two blocks
+**
+** Description: Determines whether the second block immediately
+**      follows the first one.
+*/
+#define adjacent(first,second)  \
+	( (void *) (first) + P2B((first)->pages) == (void *) (second) )
+
+/*
+** PRIVATE DATA TYPES
+*/
+
+/*
+** This structure keeps track of a single block of memory.  All blocks
+** are multiples of the base size (currently, 4KB).
+*/
+
+typedef struct block_s {
+	uint32_t pages;			// length of this block, in pages
+	struct   block_s *next;	// pointer to the next free block
+} block_t;
+
+/*
+** Memory region information returned by the BIOS
+**
+** This data consists of a 32-bit integer followed
+** by an array of region descriptor structures.
+*/
+
+// a handy union for playing with 64-bit addresses
+typedef union b64_u {
+	uint32_t part[2];
+	uint64_t all;
+} b64_t;
+
+// the halves of a 64-bit address
+#define LOW		part[0]
+#define HIGH	part[1]
+
+// memory region descriptor
+typedef struct memregion_s {
+	b64_t	 base;		// base address
+	b64_t	 length;	// region length
+	uint32_t type;		// type of region
+	uint32_t acpi;		// ACPI 3.0 info
+} __attribute__((packed)) region_t;
+
+/*
+** Region types
+*/
+
+#define REGION_USABLE		1
+#define REGION_RESERVED		2
+#define REGION_ACPI_RECL	3
+#define REGION_ACPI_NVS		4
+#define REGION_BAD			5
+
+/*
+** ACPI 3.0 bit fields
+*/
+
+#define REGION_IGNORE		0x01
+#define REGION_NONVOL		0x02
+
+/*
+** 32-bit and 64-bit address values as 64-bit literals
+*/
+
+#define ADDR_BIT_32		0x0000000100000000LL
+#define ADDR_LOW_HALF	0x00000000ffffffffLL
+#define ADDR_HIGH_HALR	0xffffffff00000000LL
+
+#define ADDR_32_MAX		ADDR_LOW_HALF
+#define ADDR_64_FIRST	ADDR_BIT_32
+
+/*
+** PRIVATE GLOBAL VARIABLES
+*/
+
+// freespace pools
+static block_t *free_pages;
+static block_t *free_slices;
+
+// initialization status
+static int km_initialized = 0;
+
+/*
+** IMPORTED GLOBAL VARIABLES
+*/
+
+extern int _end;	// end of the BSS section - provided by the linker
+
+/*
+** FUNCTIONS
+*/
+
+/*
+** FREE LIST MANAGEMENT
+*/
+
+/**
+** Name:	add_block
+**
+** Add a block to the free list. The contents of the block
+** will be modified.
+**
+** @param[in] base   Base address of the block
+** @param[in] length Block length, in bytes
+*/
+static void add_block( uint32_t base, uint32_t length ) {
+	block_t *block;
+
+	// don't add it if it isn't at least 4K
+	if( length < SZ_PAGE ) {
+		return;
+	}
+
+	// only want to add multiples of 4K; check the lower bits
+	if( (length & 0xfff) != 0 ) {
+		// round it down to 4K
+		length &= 0xfffff000;
+	}
+
+	// create the "block"
+
+	block = (block_t *) base;
+	block->pages = B2P(length);
+	block->next = NULL;
+
+#if TRACING_KMEM_FREE
+	cio_printf( "KM: add(%08x,%u): addr %08x len %u\n",
+				base, length, (uint32_t)block, block->length );
+#endif
+
+	/*
+	** We maintain the free list in order by address, to simplify
+	** coalescing adjacent free blocks.
+	**
+	** Handle the easiest case first.
+	*/
+
+	if( free_pages == NULL ) {
+		free_pages = block;
+		return;
+	}
+
+	/*
+	** Unfortunately, it's not always that easy....
+	**
+	** Find the correct insertion spot.
+	*/
+
+	block_t *prev, *curr;
+
+	prev = NULL;
+	curr = free_pages;
+
+	while( curr && curr < block ) {
+		prev = curr;
+		curr = curr->next;
+	}
+
+	// the new block always points to its successor
+	block->next = curr;
+
+	/*
+	** If prev is NULL, we're adding at the front; otherwise,
+	** we're adding after some other entry (middle or end).
+	*/
+
+	if( prev == NULL ) {
+		// sanity check - both pointers can't be NULL
+		assert( curr );
+		// add at the beginning
+		free_pages = block;
+	} else {
+		// inserting in the middle or at the end
+		prev->next = block;
+	}
+}
+
+/**
+** Name:	km_init
+**
+** Find what memory is present on the system and
+** construct the list of free memory blocks.
+**
+** Dependencies:
+**	Must be called before any other init routine that uses
+**	dynamic storage is called.
+*/
+void km_init( void ) {
+	int32_t entries;
+	region_t *region;
+	uint64_t cutoff;
+
+#if TRACING_INIT
+	// announce that we're starting initialization
+	cio_puts( " Kmem" );
+#endif
+
+	// initially, nothing in the free lists
+	free_slices = NULL;
+	free_pages = NULL;
+
+	/*
+	** We ignore all memory below the end of our OS.  In theory,
+	** we should be able to re-use much of that space; in practice,
+	** this is safer.
+	*/
+
+	// set our cutoff point as the end of the BSS section
+	cutoff = (uint32_t) &_end;
+
+	// round it up to the next multiple of 4K (0x1000)
+	if( cutoff & 0xfffLL ) {
+		cutoff &= 0xfffff000LL;
+		cutoff += 0x1000LL;
+	}
+
+	// get the list length
+	entries = *((int32_t *) MMAP_ADDRESS);
+
+#if TRACING_KEMEM
+	cio_printf( "\nKmem: %d regions\n", entries );
+#endif
+
+	// if there are no entries, we have nothing to do!
+	if( entries < 1 ) {  // note: entries == -1 could occur!
+		return;
+	}
+
+	// iterate through the entries, adding things to the freelist
+
+	region = ((region_t *) (MMAP_ADDRESS + 4));
+
+	for( int i = 0; i < entries; ++i, ++region ) {
+
+#if TRACING_KMEM
+		// report this region
+		cio_printf( "%3d: ", i );
+		cio_printf( " base %08x%08x",
+				region->base.HIGH, region->base.LOW );
+		cio_printf( " len %08x%08x",
+				region->length.HIGH, region->length.LOW );
+		cio_printf( " type %08x acpi %08x",
+				region->type, region->acpi );
+#endif
+
+		/*
+		** Determine whether or not we should ignore this region.
+		**
+		** We ignore regions for several reasons:
+		**
+		**  ACPI indicates it should be ignored
+		**  ACPI indicates it's non-volatile memory
+		**  Region type isn't "usable"
+		**  Region is above the 4GB address limit
+		**
+		** Currently, only "normal" (type 1) regions are considered
+		** "usable" for our purposes.  We could potentially expand
+		** this to include ACPI "reclaimable" memory.
+		*/
+
+		// first, check the ACPI one-bit flags
+
+		if( ((region->acpi) & REGION_IGNORE) == 0 ) {
+			cio_puts( " IGN\n" );
+			continue;
+		}
+
+		if( ((region->acpi) & REGION_NONVOL) != 0 ) {
+			cio_puts( " NVOL\n" );
+			continue;  // we'll ignore this, too
+		}
+
+		// next, the region type
+
+		if( (region->type) != REGION_USABLE ) {
+			cio_puts( " RCLM\n" );
+			continue;  // we won't attempt to reclaim ACPI memory (yet)
+		}
+
+		// OK, we have a "normal" memory region - verify that it's usable
+
+		// ignore it if it's above 4GB
+		if( region->base.HIGH != 0 ) {
+			cio_puts( " 4GB+\n" );
+			continue;
+		}
+
+		// grab the two 64-bit values to simplify things
+		uint64_t base   = region->base.all;
+		uint64_t length = region->length.all;
+
+		// see if it's below our arbitrary cutoff point
+		if( base < cutoff ) {
+
+			// is the whole thing too low, or just part?
+			if( (base + length) < cutoff ) {
+				// it's all below the cutoff!
+				cio_puts( " LOW\n" );
+				continue;
+			}
+
+			// recalculate the length, starting at our cutoff point
+			uint64_t loss = cutoff - base;
+
+			// reset the length and the base address
+			length -= loss;
+			base = cutoff;
+		}
+
+		// see if it extends beyond the 4GB boundary
+
+		if( (base + length) > ADDR_32_MAX ) {
+
+			// OK, it extends beyond the 32-bit limit; figure out
+			// how far over it goes, and lop off that portion
+
+			uint64_t loss = (base + length) - ADDR_64_FIRST;
+			length -= loss;
+		}
+
+		// we survived the gauntlet - add the new block
+
+		cio_puts( " OK\n" );
+
+		uint32_t b32 = base   & ADDR_LOW_HALF;
+		uint32_t l32 = length & ADDR_LOW_HALF;
+
+		add_block( b32, l32 );
+	}
+
+	// record the initialization
+	km_initialized = 1;
+}
+
+/**
+** Name:	km_dump
+**
+** Dump the current contents of the free list to the console
+*/
+void km_dump( void ) {
+	block_t *block;
+
+	cio_printf( "&_free_pages=%08x\n", &_free_pages );
+
+	for( block = _free_pages; block != NULL; block = block->next ) {
+		cio_printf(
+			"block @ 0x%08x 0x%08x pages (ends at 0x%08x) next @ 0x%08x\n",
+				block, block->pages, P2B(block->pages) + (uint32_t) block,
+				block->next );
+	}
+
+}
+
+/*
+** PAGE MANAGEMENT
+*/
+
+/**
+** Name:	km_page_alloc
+**
+** Allocate a page of memory from the free list.
+**
+** @param[in] count  Number of contiguous pages desired
+**
+** @return a pointer to the beginning of the first allocated page,
+**		   or NULL if no memory is available
+*/
+void *km_page_alloc( unsigned int count ) {
+
+	assert( km_initialized );
+
+	// make sure we actually need to do something!
+	if( count < 1 ) {
+		return( NULL );
+	}
+
+#if TRACING_KMEM_FREE
+	cio_printf( "KM: pg_alloc(%u)", count );
+#endif
+
+	/*
+	** Look for the first entry that is large enough.
+	*/
+
+	// pointer to the current block
+	block_t *block = free_pages;
+
+	// pointer to where the pointer to the current block is
+	block_t **pointer = &free_pages;
+
+	while( block != NULL && block->pages < count ){
+		pointer = &block->next;
+		block = *pointer;
+	}
+
+	// did we find a big enough block?
+	if( block == NULL ){
+		// nope!
+#if TRACING_KMEM_FREE
+		cio_puts( " FAIL\n" );
+#endif
+		return( NULL );
+	}
+
+	// found one!  check the length
+
+	if( block->pages == count ) {
+
+		// exactly the right size - unlink it from the list
+
+		*pointer = block->next;
+
+	} else {
+
+		// bigger than we need - carve the amount we need off
+		// the beginning of this block
+
+		// remember where this chunk begins
+		block_t *chunk = block;
+
+		// how much space will be left over?
+		int excess = block->pages - count;
+
+		// find the start of the new fragment
+		block_t *fragment = (block_t *) ( (uint8_t *) block + P2B(count) );
+
+		// set the length and link for the new fragment
+		fragment->pages = excess;
+		fragment->next  = block->next;
+
+		// replace this chunk with the fragment
+		*pointer = fragment;
+
+		// return this chunk
+		block = chunk;
+	}
+
+#if TRACING_KMEM_FREE
+	cio_printf( " -> %08x\n", (uint32_t) block );
+#endif
+
+	return( block );
+}
+
+/**
+** Name:	km_page_free
+**
+** Returns a memory block to the list of available blocks,
+** combining it with adjacent blocks if they're present.
+**
+** CRITICAL ASSUMPTION:  multi-page blocks will be freed one page
+** at a time!
+**
+** @param[in] block   Pointer to the page to be returned to the free list
+*/
+void km_page_free( void *block ){
+	block_t *used;
+	block_t *prev;
+	block_t *curr;
+
+	assert( km_initialized );
+
+	/*
+	** Don't do anything if the address is NULL.
+	*/
+	if( block == NULL ){
+		return;
+	}
+
+#if TRACING_KMEM_FREE
+	cio_printf( "KM: pg_free(%08x)", (uint32_t) block );
+#endif
+
+	used = (block_t *) block;
+
+	/*
+	** CRITICAL ASSUMPTION
+	**
+	** We assume that any multi-page block that is being freed will
+	** be freed one page at a time.  We make this assumption because we
+	** don't track allocation sizes.  We can't use the simple "allocate
+	** four extra bytes before the returned pointer" scheme to do this
+	** because we're managing pages, and the pointers we return must point
+	** to page boundaries, so we would wind up allocating an extra page
+	** for each allocation.
+	**
+	** Alternatively, we could keep an array of addresses and block
+	** sizes ourselves, but that feels clunky, and would risk running out
+	** of table entries if there are lots of allocations (assuming we use
+	** a 4KB page to hold the table, at eight bytes per entry we would have
+	** 512 entries per page).
+	**
+	** IF THIS ASSUMPTION CHANGES, THIS CODE MUST BE FIXED!!!
+	*/
+
+	used->pages = 1;
+
+	/*
+	** Advance through the list until current and previous
+	** straddle the place where the new block should be inserted.
+	*/
+	prev = NULL;
+	curr = free_pages;
+
+	while( curr != NULL && curr < used ){
+		prev = curr;
+		curr = curr->next;
+	}
+
+	/*
+	** At this point, we have the following list structure:
+	**
+	**   ....	BLOCK		BLOCK		....
+	**			(*prev)  ^  (*curr)
+	**					 |
+	**				"used" goes here
+	**
+	** We may need to merge the inserted block with either its
+	** predecessor or its successor (or both).
+	*/
+
+	/*
+	** If this is not the first block in the resulting list,
+	** we may need to merge it with its predecessor.
+	*/
+	if( prev != NULL ){
+
+		// There is a predecessor.  Check to see if we need to merge.
+		if( adjacent( prev, used ) ){
+
+			// yes - merge them
+			prev->pages += used->pages;
+
+			// the predecessor becomes the "newly inserted" block,
+			// because we still need to check to see if we should
+			// merge with the successor
+			used = prev;
+
+		} else {
+
+			// Not adjacent - just insert the new block
+			// between the predecessor and the successor.
+			used->next = prev->next;
+			prev->next = used;
+
+		}
+
+	} else {
+
+		// Yes, it is first.  Update the list pointer to insert it.
+		used->next = free_pages;
+		free_pages = used;
+
+	}
+
+	/*
+	** If this is not the last block in the resulting list,
+	** we may (also) need to merge it with its successor.
+	*/
+	if( curr != NULL ){
+
+		// No.  Check to see if it should be merged with the successor.
+		if( adjacent( used, curr ) ){
+
+			// Yes, combine them.
+			used->next = curr->next;
+			used->pages += curr->pages;
+
+		}
+	}
+}
+
+/*
+** SLICE MANAGEMENT
+*/
+
+/*
+** Slices are 1024-byte fragments from pages.  We maintain a free list of
+** slices for those parts of the OS which don't need full 4096-byte chunks
+** of space (e.g., the QNode and Queue allocators).
+*/
+
+/**
+** Name:	carve_slices
+**
+** Allocate a page and split it into four slices;  If no
+** memory is available, we panic.
+*/
+static void carve_slices( void ) {
+	void *page;
+
+	// get a page
+	page = km_page_alloc( 1 );
+
+	// allocation failure is a show-stopping problem
+	assert( page );
+
+	// we have the page; create the four slices from it
+	uint8_t *ptr = (uint8_t *) page;
+	for( int i = 0; i < 4; ++i ) {
+		km_slice_free( (void *) ptr );
+		ptr += SZ_SLICE;
+	}
+}
+
+/**
+** Name:	km_slice_alloc
+**
+** Dynamically allocates a slice (1/4 of a page).  If no
+** memory is available, we panic.
+**
+** @return a pointer to the allocated slice
+*/
+void *km_slice_alloc( void ) {
+	block_t *slice;
+
+	assert( km_initialized );
+
+#if TRACING_KMEM_FREE
+	cio_printf( "KM: sl_alloc()\n" );
+#endif
+
+	// if we are out of slices, create a few more
+	if( free_slices == NULL ) {
+		carve_slices();
+	}
+
+	// take the first one from the free list
+	slice = free_slices;
+	assert( slice != NULL );
+
+	// unlink it
+	free_slices = slice->next;
+
+	// make it nice and shiny for the caller
+	memclr( (void *) slice, SZ_SLICE );
+
+	return( slice );
+}
+
+/**
+** Name:	km_slice_free
+**
+** Returns a slice to the list of available slices.
+**
+** We make no attempt to merge slices, as they are independent
+** blocks of memory (unlike pages).
+**
+** @param[in] block  Pointer to the slice (1/4 page) to be freed
+*/
+void km_slice_free( void *block ) {
+	block_t *slice = (block_t *) block;
+
+	assert( km_initialized );
+
+#if TRACING_KMEM_FREE
+	cio_printf( "KM: sl_free(%08x)\n", (uint32_t) block );
+#endif
+
+	// just add it to the front of the free list
+	slice->pages = SZ_SLICE;
+	slice->next = free_slices;
+	free_slices = slice;
+}