/*
 * 3215 console initialization code called from console_init().
 * NOTE: This is called before kmalloc is available.
 */
static int __init
con3215_init(void)
{
	struct ccw_device *cdev;
	struct raw3215_info *raw;
	struct raw3215_req *req;
	int i;

	/* Check if 3215 is to be the console */
	if (!CONSOLE_IS_3215)
		return -ENODEV;

	/* Set the console mode for VM */
	if (MACHINE_IS_VM) {
		cpcmd("TERM CONMODE 3215", NULL, 0);
		cpcmd("TERM AUTOCR OFF", NULL, 0);
	}

	/* allocate 3215 request structures */
	raw3215_freelist = NULL;
	spin_lock_init(&raw3215_freelist_lock);
	for (i = 0; i < NR_3215_REQ; i++) {
		req = (struct raw3215_req *) alloc_bootmem_low(sizeof(struct raw3215_req));
		req->next = raw3215_freelist;
		raw3215_freelist = req;
	}

	cdev = ccw_device_probe_console();
	if (!cdev)
		return -ENODEV;

	raw3215[0] = raw = (struct raw3215_info *)
		alloc_bootmem_low(sizeof(struct raw3215_info));
	memset(raw, 0, sizeof(struct raw3215_info));
	raw->buffer = (char *) alloc_bootmem_low(RAW3215_BUFFER_SIZE);
	raw->inbuf = (char *) alloc_bootmem_low(RAW3215_INBUF_SIZE);
	raw->cdev = cdev;
	raw->lock = get_ccwdev_lock(cdev);
	cdev->dev.driver_data = raw;
	cdev->handler = raw3215_irq;

	raw->flags |= RAW3215_FIXED;
	tasklet_init(&raw->tasklet,
		     (void (*)(unsigned long)) raw3215_tasklet,
		     (unsigned long) raw);
	init_waitqueue_head(&raw->empty_wait);

	/* Request the console irq */
	if (raw3215_startup(raw) != 0) {
		free_bootmem((unsigned long) raw->inbuf, RAW3215_INBUF_SIZE);
		free_bootmem((unsigned long) raw->buffer, RAW3215_BUFFER_SIZE);
		free_bootmem((unsigned long) raw, sizeof(struct raw3215_info));
		raw3215[0] = NULL;
		printk("Couldn't find a 3215 console device\n");
		return -ENODEV;
	}
	register_console(&con3215);
	return 0;
}

/*
 * 3215 console initialization code called from console_init().
 * NOTE: This is called before kmalloc is available.
 */
void __init con3215_init(void)
{
	raw3215_info *raw;
	raw3215_req *req;
	int irq;
	int i;

	/* Check if 3215 is to be the console */
	if (!CONSOLE_IS_3215)
		return;
	irq = raw3215_find_dev(0);

	/* Set the console mode for VM */
	if (MACHINE_IS_VM) {
		cpcmd("TERM CONMODE 3215", NULL, 0);
		cpcmd("TERM AUTOCR OFF", NULL, 0);
	}

	/* allocate 3215 request structures */
	raw3215_freelist = NULL;
	spin_lock_init(&raw3215_freelist_lock);
	for (i = 0; i < NR_3215_REQ; i++) {
                req = (raw3215_req *) alloc_bootmem_low(sizeof(raw3215_req));
		req->next = raw3215_freelist;
		raw3215_freelist = req;
	}

	ctrlchar_init();

#ifdef CONFIG_TN3215_CONSOLE
        raw3215[0] = raw = (raw3215_info *)
                alloc_bootmem_low(sizeof(raw3215_info));
	memset(raw, 0, sizeof(raw3215_info));
        raw->buffer = (char *) alloc_bootmem_low(RAW3215_BUFFER_SIZE);
        raw->inbuf = (char *) alloc_bootmem_low(RAW3215_INBUF_SIZE);

	/* Find the first console */
	raw->irq = raw3215_find_dev(0);
	raw->flags |= RAW3215_FIXED;
	raw->tqueue.routine = raw3215_softint;
	raw->tqueue.data = raw;
        init_waitqueue_head(&raw->empty_wait);

	/* Request the console irq */
	if ( raw3215_startup(raw) != 0 )
		raw->irq = -1;

	if (raw->irq != -1) {
		register_console(&con3215);
	} else {
                free_bootmem((unsigned long) raw->inbuf, RAW3215_INBUF_SIZE);
                free_bootmem((unsigned long) raw->buffer, RAW3215_BUFFER_SIZE);
                free_bootmem((unsigned long) raw, sizeof(raw3215_info));
		raw3215[0] = NULL;
		printk("Couldn't find a 3215 console device\n");
	}
#endif
}

void __init setup_physmem(unsigned long start, unsigned long reserve_end,
			  unsigned long len, unsigned long long highmem)
{
	unsigned long reserve = reserve_end - start;
	int pfn = PFN_UP(__pa(reserve_end));
	int delta = (len - reserve) >> PAGE_SHIFT;
	int err, offset, bootmap_size;

	physmem_fd = create_mem_file(len + highmem);

	offset = uml_reserved - uml_physmem;
	err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
			    len - offset, 1, 1, 1);
	if (err < 0) {
		printf("setup_physmem - mapping %ld bytes of memory at 0x%p "
		       "failed - errno = %d\n", len - offset,
		       (void *) uml_reserved, err);
		exit(1);
	}

	/*
	 * Special kludge - This page will be mapped in to userspace processes
	 * from physmem_fd, so it needs to be written out there.
	 */
	os_seek_file(physmem_fd, __pa(&__syscall_stub_start));
	os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE);

	bootmap_size = init_bootmem(pfn, pfn + delta);
	free_bootmem(__pa(reserve_end) + bootmap_size,
		     len - bootmap_size - reserve);
}

void __init device_tree_init(void)
{
	unsigned long base, size;
	void *fdt_copy;

	if (!initial_boot_params)
		return;

	base = virt_to_phys((void *)initial_boot_params);
	size = be32_to_cpu(initial_boot_params->totalsize);

	/* Before we do anything, lets reserve the dt blob */
	reserve_bootmem(base, size, BOOTMEM_DEFAULT);

	/* The strings in the flattened tree are referenced directly by the
	 * device tree, so copy the flattened device tree from init memory
	 * to regular memory.
	 */
	fdt_copy = alloc_bootmem(size);
	memcpy(fdt_copy, initial_boot_params, size);
	initial_boot_params = fdt_copy;

	unflatten_device_tree();

	/* free the space reserved for the dt blob */
	free_bootmem(base, size);
}

static ssize_t __init setup_pcpu_4k(size_t static_size)
{
	size_t pages_size;
	unsigned int cpu;
	int i, j;
	ssize_t ret;

	pcpu4k_nr_static_pages = PFN_UP(static_size);

	/* unaligned allocations can't be freed, round up to page size */
	pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * num_possible_cpus()
			       * sizeof(pcpu4k_pages[0]));
	pcpu4k_pages = alloc_bootmem(pages_size);

	/* allocate and copy */
	j = 0;
	for_each_possible_cpu(cpu)
		for (i = 0; i < pcpu4k_nr_static_pages; i++) {
			void *ptr;

			ptr = pcpu_alloc_bootmem(cpu, PAGE_SIZE, PAGE_SIZE);
			if (!ptr)
				goto enomem;

			memcpy(ptr, __per_cpu_load + i * PAGE_SIZE, PAGE_SIZE);
			pcpu4k_pages[j++] = virt_to_page(ptr);
		}

	/* we're ready, commit */
	pr_info("PERCPU: Allocated %d 4k pages, static data %zu bytes\n",
		pcpu4k_nr_static_pages, static_size);

	ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size,
				     PERCPU_FIRST_CHUNK_RESERVE, -1,
				     -1, NULL, pcpu4k_populate_pte);
	goto out_free_ar;

enomem:
	while (--j >= 0)
		free_bootmem(__pa(page_address(pcpu4k_pages[j])), PAGE_SIZE);
	ret = -ENOMEM;
out_free_ar:
	free_bootmem(__pa(pcpu4k_pages), pages_size);
	return ret;
}

static void __ref free_p2m_page(void *p)
{
	if (unlikely(!slab_is_available())) {
		free_bootmem((unsigned long)p, PAGE_SIZE);
		return;
	}

	free_page((unsigned long)p);
}

// start_pfn : 뱅크 0 시작 주소의 물리 small page 번호		(0x20000)
// end_pfn   : 뱅크 0의 마지막 주소의 물리 small page 번호	(0x4f800)
static void __init arm_bootmem_init(unsigned long start_pfn,
	unsigned long end_pfn)
{
	struct memblock_region *reg;
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;
	// pg_data_t : struct pglist_data

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	// boot_pages : 6
	// start_pfn ~ end_pfn 까지를 bitmap으로 바꿨을 때 총 프레임의 갯수가 반환됨.
	
	// boot_pages << PAGE_SHIFT : 0x6000, L1_CACHE_BYTES : 64, _pfn_to_phys(end_pfn) : 0x4F800000
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));
	// non-reserved 영역에서 비트맵용 영역을 만들어 가져옴
	// 영역의 시작 주소가 반환됨(물리)

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);	// 비어 있는 함수임
	pgdat = NODE_DATA(0);
	//*pgdat = contig_page_data
	//
	//	.bdata = &bootmem_node_data[0]
	//			 현재는 0으로 되어 있는 값임
	//
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
	// bdata_list 에 등록
	// bitmap 값을 0xFF로 초기화

	/* Free the lowmem regions from memblock into bootmem. */
	for_each_memblock(memory, reg) {
	// for (reg = memblock.memory.regions; reg < (memblock.memory.regions + memblock.memory.cnt), reg++)
		unsigned long start = memblock_region_memory_base_pfn(reg);
		unsigned long end = memblock_region_memory_end_pfn(reg);
		// start : 0x20000
		// end   : 0xA0000

		if (end >= end_pfn)
			end = end_pfn;
		if (start >= end)
			break;
		
		// start : 0x20000000, (end - start) << PAGE_SHIFT : 0x2F800000
		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
		// start부터 end에 해당하는 bitmap을 전부 0으로 설정
		// 일단 전부 FREE로 만듬
	}

static void __init pcpu_fc_free(void *ptr, size_t size)
{
#ifdef CONFIG_NO_BOOTMEM
	u64 start = __pa(ptr);
	u64 end = start + size;
	free_early_partial(start, end);
#else
	free_bootmem(__pa(ptr), size);
#endif
}

void __init bootmem_init(void)
{
	unsigned long bootmap_size;

	/*
	 * Init memory
	 */
	physical_memory_start = sdram_start;
	physical_memory_end = sdram_start+sdram_size;
	if( ((unsigned long)_end < physical_memory_start) || ((unsigned long)_end > physical_memory_end) )
		printk("BUG: your kernel is not located in the ddr sdram");
	/* start after kernel code */
	memory_start = PAGE_ALIGN((unsigned long)_end);
	memory_end = physical_memory_end;
#ifdef DEBUG
	printk("memory from %lx - %lx\n", memory_start, memory_end);
#endif

	init_mm.start_code = (unsigned long)_stext;
	init_mm.end_code = (unsigned long)_etext;
	init_mm.end_data = (unsigned long)_edata;
	init_mm.brk = (unsigned long)0;

	/*
	 * Give all the memory to the bootmap allocator, tell it to put the
	 * boot mem_map at the start of memory.
	 */
	bootmap_size = init_bootmem_node(
			NODE_DATA(0),
			memory_start >> PAGE_SHIFT, /* map goes here */
			PAGE_OFFSET >> PAGE_SHIFT,
			memory_end >> PAGE_SHIFT);

	/*
	 * Free the usable memory, we have to make sure we do not free
	 * the bootmem bitmap so we then reserve it after freeing it :-)
	 */
	free_bootmem(memory_start, memory_end - memory_start);
	reserve_bootmem(memory_start, bootmap_size);

	/*
	 * reserve initrd boot memory
	 */
#ifdef CONFIG_BLK_DEV_INITRD
	if(_kernel_arg_initrd_start) {
		unsigned long reserve_start = _kernel_arg_initrd_start & PAGE_MASK;
		unsigned long reserve_end = (_kernel_arg_initrd_end + PAGE_SIZE-1) & PAGE_MASK;
		initrd_start = _kernel_arg_initrd_start;
		initrd_end = _kernel_arg_initrd_end;
		printk("reserving initrd memory: %lx size %lx\n", reserve_start, reserve_end-reserve_start);
		reserve_bootmem(reserve_start, reserve_end-reserve_start);
	}
#endif
}

void __init free_tce_table(void *tbl)
{
	unsigned int size;

	if (!tbl)
		return;

	size = table_size_to_number_of_entries(specified_table_size);
	size *= TCE_ENTRY_SIZE;

	free_bootmem(__pa(tbl), size);
}

/* Load data from a file called NAME into ram.  The address and length
   of the data image are returned in ADDR and LEN.  */
static int __init
read_file (const char *name,
	   unsigned long *addr, unsigned long *len,
	   const char **err)
{
	int rval, fd;
	unsigned long cur, left;
	/* Note this is not a normal stat buffer, it's an ad-hoc
	   structure defined by the simulator.  */
	unsigned long stat_buf[10];

	/* Stat the file to find out the length.  */
	rval = V850_SIM_SYSCALL (stat, name, stat_buf);
	if (rval < 0) {
		if (err) *err = "stat";
		return 0;
	}
	*len = stat_buf[4];

	/* Open the file; `0' is O_RDONLY.  */
	fd = V850_SIM_SYSCALL (open, name, 0);
	if (fd < 0) {
		if (err) *err = "open";
		return 0;
	}

	*addr = (unsigned long)alloc_bootmem(*len);
	if (! *addr) {
		V850_SIM_SYSCALL (close, fd);
		if (err) *err = "alloc_bootmem";
		return 0;
	}

	cur = *addr;
	left = *len;
	while (left > 0) {
		int chunk = V850_SIM_SYSCALL (read, fd, cur, left);
		if (chunk <= 0)
			break;
		cur += chunk;
		left -= chunk;
	}
	V850_SIM_SYSCALL (close, fd);
	if (left > 0) {
		/* Some read failed.  */
		free_bootmem (*addr, *len);
		if (err) *err = "read";
		return 0;
	}

	return 1;
}

// ARM10C 20131207
// min: 0x20000, max_low: 0x4f800
static void __init arm_bootmem_init(unsigned long start_pfn,
	unsigned long end_pfn)
{
	struct memblock_region *reg;
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	// start_pfn: 0x20000, end_pfn: 0x4f800, end_pfn - start_pfn: 0x2f800
	// boot_pages: 0x6
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);

	// boot_pages << PAGE_SHIFT: 0x6000, L1_CACHE_BYTES: 64
	// __pfn_to_phys(0x4f800); 0x4f800000
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);

	// pglist_data.bdata 의 bootmem_node_data 주소로 설정
	pgdat = NODE_DATA(0);

	// pgdat: ?, __phys_to_pfn(bitmap): ?, start_pfn: 0x20000, end_pfn: 0x4f800
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

	/* Free the lowmem regions from memblock into bootmem. */
	for_each_memblock(memory, reg) {
		// start: 0x20000
		unsigned long start = memblock_region_memory_base_pfn(reg);
		// end: 0xA0000
		unsigned long end = memblock_region_memory_end_pfn(reg);

		// end: 0xA0000, end_pfn: 0x4f800
		if (end >= end_pfn)
			// end: 0x4f800
			end = end_pfn;
		// start: 0x20000, end: 0x4f800
		if (start >= end)
			break;

		// __pfn_to_phys(0x20000): 0x20000000, (end - start) << PAGE_SHIFT: 0x2f800000
		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
	}

void __init do_init_bootmem(void)
{
	unsigned long i;
	unsigned long start, bootmap_pages;
	unsigned long total_pages;
	int boot_mapsize;

	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
	total_pages = total_lowmem >> PAGE_SHIFT;
#endif

	/*
	 * Find an area to use for the bootmem bitmap.  Calculate the size of
	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
	 * Add 1 additional page in case the address isn't page-aligned.
	 */
	bootmap_pages = bootmem_bootmap_pages(total_pages);

	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
	BUG_ON(!start);

	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

	/* Add all physical memory to the bootmem map, mark each area
	 * present.
	 */
	for (i = 0; i < lmb.memory.cnt; i++) {
		unsigned long base = lmb.memory.region[i].base;
		unsigned long size = lmb_size_bytes(&lmb.memory, i);
#ifdef CONFIG_HIGHMEM
		if (base >= total_lowmem)
			continue;
		if (base + size > total_lowmem)
			size = total_lowmem - base;
#endif
		free_bootmem(base, size);
	}

	/* reserve the sections we're already using */
	for (i = 0; i < lmb.reserved.cnt; i++)
		reserve_bootmem(lmb.reserved.region[i].base,
				lmb_size_bytes(&lmb.reserved, i));

	/* XXX need to clip this if using highmem? */
	for (i = 0; i < lmb.memory.cnt; i++)
		memory_present(0, lmb_start_pfn(&lmb.memory, i),
			       lmb_end_pfn(&lmb.memory, i));
	init_bootmem_done = 1;
}

void __init mem_init(void)
{
	int codek = 0, datak = 0, initk = 0;
	unsigned long tmp, ram_start, ram_end, len;
	extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;

	unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
	unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
	processor_dram(&ram_start, &ram_end);
	len = (ram_end - ram_start) + OCMSIZE;
#ifdef DEBUG
	printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
#endif

	end_mem &= PAGE_MASK;
	high_memory = (void *) end_mem;

	start_mem = PAGE_ALIGN(start_mem);
	max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;

	/* this will put all memory onto the freelists */
#ifdef CONFIG_ZONE_DMA
	{
		unsigned long ocm_free_begin = (unsigned long)&__ocm_free_begin;
		unsigned long ocm_free_end = (unsigned long)&__ocm_free_end;
		unsigned long zone_dma_begin = (ocm_free_begin + PAGE_SIZE - 1) & PAGE_MASK;
		unsigned long zone_dma_end = ocm_free_end & PAGE_MASK;
		if (zone_dma_end > zone_dma_begin)
			free_bootmem(zone_dma_begin, zone_dma_end-zone_dma_begin);
	}
#endif
	totalram_pages = free_all_bootmem();

	codek = (&_etext - &_stext) >> 10;
	datak = (&_ebss - &_sdata) >> 10;
	initk = (&__init_begin - &__init_end) >> 10;

	tmp = nr_free_pages() << PAGE_SHIFT;
	printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
	       tmp >> 10,
	       len >> 10,
	       codek,
	       datak
	       );

}

void __init device_tree_init(void)
{
	unsigned long base, size;

	if (!initial_boot_params)
		return;

	base = virt_to_phys((void *)initial_boot_params);
	size = be32_to_cpu(initial_boot_params->totalsize);

	/* Before we do anything, lets reserve the dt blob */
	reserve_bootmem(base, size, BOOTMEM_DEFAULT);

	unflatten_device_tree();

	/* free the space reserved for the dt blob */
	free_bootmem(base, size);
}

static void __init bootmem_init(void)
{
	unsigned long start_pfn, bootmap_size;
	unsigned long size = initrd_end - initrd_start;

	start_pfn = PFN_UP(__pa(&_end));

	min_low_pfn = PFN_UP(MEMORY_START);
	max_low_pfn = PFN_UP(MEMORY_START + MEMORY_SIZE);

	/* Initialize the boot-time allocator with low memory only. */
	bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
					 min_low_pfn, max_low_pfn);
	add_active_range(0, min_low_pfn, max_low_pfn);

	free_bootmem(PFN_PHYS(start_pfn),
		     (max_low_pfn - start_pfn) << PAGE_SHIFT);
	memory_present(0, start_pfn, max_low_pfn);

	/* Reserve space for the bootmem bitmap. */
	reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size, BOOTMEM_DEFAULT);

	if (size == 0) {
		printk(KERN_INFO "Initrd not found or empty");
		goto disable;
	}

	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
		printk(KERN_ERR "Initrd extends beyond end of memory");
		goto disable;
	}

	/* Reserve space for the initrd bitmap. */
	reserve_bootmem(__pa(initrd_start), size, BOOTMEM_DEFAULT);
	initrd_below_start_ok = 1;

	pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
		 initrd_start, size);
	return;
disable:
	printk(KERN_CONT " - disabling initrd\n");
	initrd_start = 0;
	initrd_end = 0;
}

static void __init arm_bootmem_init(struct meminfo *mi,
	unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;
	int i;

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);
	pgdat = NODE_DATA(0);
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

	for_each_bank(i, mi) {
		struct membank *bank = &mi->bank[i];
		if (!bank->highmem)
			free_bootmem(bank_phys_start(bank), bank_phys_size(bank));
	}

	/*
	 * Reserve the memblock reserved regions in bootmem.
	 */
	for (i = 0; i < memblock.reserved.cnt; i++) {
		phys_addr_t start = memblock_start_pfn(&memblock.reserved, i);
		if (start >= start_pfn &&
		    memblock_end_pfn(&memblock.reserved, i) <= end_pfn)
			reserve_bootmem_node(pgdat, __pfn_to_phys(start),
				memblock_size_bytes(&memblock.reserved, i),
				BOOTMEM_DEFAULT);
	}
}

/*
 * Register fully available low RAM pages with the bootmem allocator.
 */
static void __init register_bootmem_low_pages(void)
{
	unsigned long curr_pfn, last_pfn, pages;

	/*
	 * We are rounding up the start address of usable memory:
	 */
	curr_pfn = PFN_UP(__MEMORY_START);

	/*
	 * ... and at the end of the usable range downwards:
	 */
	last_pfn = PFN_DOWN(__pa(memory_end));

	if (last_pfn > max_low_pfn)
		last_pfn = max_low_pfn;

	pages = last_pfn - curr_pfn;
	free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(pages));
}

int orion_sysinit(void)
{
	unsigned long mem_size, free_start, free_end, start_pfn, bootmap_size;
	
	mips_machgroup = MACH_GROUP_ORION;
	/* 64 MB non-upgradable */
	mem_size = 32 << 20;
	
	free_start = PHYSADDR(PFN_ALIGN(&_end));
	free_end = mem_size;
	start_pfn = PFN_UP((unsigned long)&_end);
	
	/* Register all the contiguous memory with the bootmem allocator
	   and free it.  Be careful about the bootmem freemap.  */
	bootmap_size = init_bootmem(start_pfn, mem_size >> PAGE_SHIFT);
	
	/* Free the entire available memory after the _end symbol.  */
	free_start += bootmap_size;
	free_bootmem(free_start, free_end-free_start);
}

static unsigned long __init setup_memory(void)
{
	unsigned long bootmap_size, start_pfn, max_low_pfn;


#define PFN_UP(x)       (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
#define PFN_PHYS(x)     ((x) << PAGE_SHIFT)

#ifndef CONFIG_FB_OC_SHMEM_SIZE
#define CONFIG_FB_OC_SHMEM_SIZE 0
#endif /* CONFIG_FB_OC_SHMEM_SIZE */


	/* min_low_pfn points to the start of DRAM, start_pfn points
	 * to the first DRAM pages after the kernel, and max_low_pfn
	 * to the end of DRAM. Partial pages are not useful, so round it 
	 * down.
	 */ 
	start_pfn   = PFN_UP(__pa(&_end));
	max_low_pfn = PFN_DOWN(CONFIG_OR32_MEMORY_SIZE
			       -CONFIG_FB_OC_SHMEM_SIZE
			       -CONFIG_OR32_RESERVED_MEM_SIZE);
	min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;

#undef CONFIG_FB_OC_SHMEM_SIZE

	/*
	 * set the beginning of frame buffer
	 */
	fb_mem_start = PFN_PHYS(max_low_pfn);

	/* 
	 * initialize the boot-time allocator (with low memory only)
	 */ 
	bootmap_size = init_bootmem(start_pfn, max_low_pfn);
	free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_low_pfn - start_pfn));
	reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size);

	return(max_low_pfn);
}