コード例 #1
0
/*
 * Initial entry point on startup. This gets called before main() is
 * entered.
 * It should be responsible for setting up everything that must be
 * in place when main is called.
 * This includes
 *   Taking a copy of the boot configuration structure.
 *   Initialising the physical console so characters can be printed.
 *   Setting up page tables for the kernel
 *   Relocating the kernel to the bottom of physical memory
 */
u_int
initarm(void *arg)
{
        int loop;
	int loop1;
	u_int kerneldatasize, symbolsize;
	vaddr_t l1pagetable;
	vaddr_t freemempos;
#if NKSYMS || defined(DDB) || defined(MODULAR)
        Elf_Shdr *sh;
#endif

	cpu_reset_address = ixp12x0_reset;

        /*
         * Since we map v0xf0000000 == p0x90000000, it's possible for
         * us to initialize the console now.
         */
	consinit();

#ifdef VERBOSE_INIT_ARM
	/* Talk to the user */
	printf("\nNetBSD/evbarm (IXM1200) booting ...\n");
#endif

	/*
	 * Heads up ... Setup the CPU / MMU / TLB functions
	 */
	if (set_cpufuncs())
		panic("CPU not recognized!");

	/* XXX overwrite bootconfig to hardcoded values */
	bootconfig.dram[0].address = 0xc0000000;
	bootconfig.dram[0].pages   = 0x10000000 / PAGE_SIZE; /* SDRAM 256MB */
	bootconfig.dramblocks = 1;

	kerneldatasize = (uint32_t)&end - (uint32_t)KERNEL_TEXT_BASE;

	symbolsize = 0;

#ifdef PMAP_DEBUG
	pmap_debug(-1);
#endif

#if NKSYMS || defined(DDB) || defined(MODULAR)
        if (! memcmp(&end, "\177ELF", 4)) {
                sh = (Elf_Shdr *)((char *)&end + ((Elf_Ehdr *)&end)->e_shoff);
                loop = ((Elf_Ehdr *)&end)->e_shnum;
                for(; loop; loop--, sh++)
                        if (sh->sh_offset > 0 &&
                            (sh->sh_offset + sh->sh_size) > symbolsize)
                                symbolsize = sh->sh_offset + sh->sh_size;
        }
#endif
#ifdef VERBOSE_INIT_ARM
	printf("kernsize=0x%x\n", kerneldatasize);
#endif
	kerneldatasize += symbolsize;
	kerneldatasize = ((kerneldatasize - 1) & ~(PAGE_SIZE * 4 - 1)) + PAGE_SIZE * 8;

	/*
	 * Set up the variables that define the availablilty of physcial
	 * memory
	 */
	physical_start = bootconfig.dram[0].address;
	physical_end = physical_start + (bootconfig.dram[0].pages * PAGE_SIZE);

	physical_freestart = physical_start
		+ (KERNEL_TEXT_BASE - KERNEL_BASE) + kerneldatasize;
	physical_freeend = physical_end;

	physmem = (physical_end - physical_start) / PAGE_SIZE;

	freemempos = 0xc0000000;

#ifdef VERBOSE_INIT_ARM
	printf("Allocating page tables\n");
#endif
	free_pages = (physical_freeend - physical_freestart) / PAGE_SIZE;

#ifdef VERBOSE_INIT_ARM
	printf("CP15 Register1 = 0x%08x\n", cpu_get_control());
	printf("freestart = 0x%08lx, free_pages = %d (0x%08x)\n",
		physical_freestart, free_pages, free_pages);
	printf("physical_start = 0x%08lx, physical_end = 0x%08lx\n",
		physical_start, physical_end);
#endif

	/* Define a macro to simplify memory allocation */
#define valloc_pages(var, np)			\
	alloc_pages((var).pv_pa, (np));		\
	(var).pv_va = KERNEL_BASE + (var).pv_pa - physical_start;
#define alloc_pages(var, np)				\
	(var) = freemempos;				\
	memset((char *)(var), 0, ((np) * PAGE_SIZE));	\
	freemempos += (np) * PAGE_SIZE;

	loop1 = 0;
	for (loop = 0; loop <= NUM_KERNEL_PTS; ++loop) {
		/* Are we 16KB aligned for an L1 ? */
		if (((physical_freeend - L1_TABLE_SIZE) & (L1_TABLE_SIZE - 1)) == 0
		    && kernel_l1pt.pv_pa == 0) {
			valloc_pages(kernel_l1pt, L1_TABLE_SIZE / PAGE_SIZE);
		} else {
			valloc_pages(kernel_pt_table[loop1],
			    L2_TABLE_SIZE / PAGE_SIZE);
			++loop1;
		}
	}

#ifdef DIAGNOSTIC
	/* This should never be able to happen but better confirm that. */
	if (!kernel_l1pt.pv_pa || (kernel_l1pt.pv_pa & (L1_TABLE_SIZE-1)) != 0)
		panic("initarm: Failed to align the kernel page directory");
#endif

	/*
	 * Allocate a page for the system page mapped to V0x00000000
	 * This page will just contain the system vectors and can be
	 * shared by all processes.
	 */
	alloc_pages(systempage.pv_pa, 1);

	/* Allocate stacks for all modes */
	valloc_pages(irqstack, IRQ_STACK_SIZE);
	valloc_pages(abtstack, ABT_STACK_SIZE);
	valloc_pages(undstack, UND_STACK_SIZE);
	valloc_pages(kernelstack, UPAGES);

#ifdef VERBOSE_INIT_ARM
	printf("IRQ stack: p0x%08lx v0x%08lx\n", irqstack.pv_pa, irqstack.pv_va); 
	printf("ABT stack: p0x%08lx v0x%08lx\n", abtstack.pv_pa, abtstack.pv_va); 
	printf("UND stack: p0x%08lx v0x%08lx\n", undstack.pv_pa, undstack.pv_va); 
	printf("SVC stack: p0x%08lx v0x%08lx\n", kernelstack.pv_pa, kernelstack.pv_va); 
#endif

	alloc_pages(msgbufphys, round_page(MSGBUFSIZE) / PAGE_SIZE);

#ifdef CPU_IXP12X0
        /*
         * XXX totally stuffed hack to work round problems introduced
         * in recent versions of the pmap code. Due to the calls used there
         * we cannot allocate virtual memory during bootstrap.
         */
	for(;;) {
		alloc_pages(ixp12x0_cc_base, 1);
		if (! (ixp12x0_cc_base & (CPU_IXP12X0_CACHE_CLEAN_SIZE - 1)))
			break;
	}
	{
		vaddr_t dummy;
		alloc_pages(dummy, CPU_IXP12X0_CACHE_CLEAN_SIZE / PAGE_SIZE - 1);
	}
	ixp12x0_cache_clean_addr = ixp12x0_cc_base;
	ixp12x0_cache_clean_size = CPU_IXP12X0_CACHE_CLEAN_SIZE / 2;
#endif /* CPU_IXP12X0 */

#ifdef VERBOSE_INIT_ARM
	printf("Creating L1 page table at 0x%08lx\n", kernel_l1pt.pv_pa);
#endif

	/*
	 * Now we start construction of the L1 page table
	 * We start by mapping the L2 page tables into the L1.
	 * This means that we can replace L1 mappings later on if necessary
	 */
	l1pagetable = kernel_l1pt.pv_pa;

	/* Map the L2 pages tables in the L1 page table */
	pmap_link_l2pt(l1pagetable, ARM_VECTORS_HIGH & ~(0x00400000 - 1),
	    &kernel_pt_table[KERNEL_PT_SYS]);

	for (loop = 0; loop < KERNEL_PT_KERNEL_NUM; loop++)
		pmap_link_l2pt(l1pagetable, KERNEL_BASE + loop * 0x00400000,
		    &kernel_pt_table[KERNEL_PT_KERNEL + loop]);

	for (loop = 0; loop < KERNEL_PT_VMDATA_NUM; loop++)
		pmap_link_l2pt(l1pagetable, KERNEL_VM_BASE + loop * 0x00400000,
		    &kernel_pt_table[KERNEL_PT_VMDATA + loop]);

	/* update the top of the kernel VM */
	pmap_curmaxkvaddr =
	    KERNEL_VM_BASE + (KERNEL_PT_VMDATA_NUM * 0x00400000);

	pmap_link_l2pt(l1pagetable, IXP12X0_IO_VBASE,
	    &kernel_pt_table[KERNEL_PT_IO]);

#ifdef VERBOSE_INIT_ARM
	printf("Mapping kernel\n");
#endif

#if XXX
	/* Now we fill in the L2 pagetable for the kernel code/data */
	{
		extern char etext[], _end[];
		size_t textsize = (uintptr_t) etext - KERNEL_TEXT_BASE;
		size_t totalsize = (uintptr_t) _end - KERNEL_TEXT_BASE;
		u_int logical;

		textsize = (textsize + PGOFSET) & ~PGOFSET;
		totalsize = (totalsize + PGOFSET) & ~PGOFSET;
                
		logical = 0x00200000;   /* offset of kernel in RAM */

		logical += pmap_map_chunk(l1pagetable, KERNEL_BASE + logical,
		    physical_start + logical, textsize,
		    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
		logical += pmap_map_chunk(l1pagetable, KERNEL_BASE + logical,
		    physical_start + logical, totalsize - textsize,
		    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	}
#else
	{
		pmap_map_chunk(l1pagetable, KERNEL_TEXT_BASE,
                    KERNEL_TEXT_BASE, kerneldatasize,
                    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	}
#endif

#ifdef VERBOSE_INIT_ARM
        printf("Constructing L2 page tables\n");
#endif

	/* Map the stack pages */
	pmap_map_chunk(l1pagetable, irqstack.pv_va, irqstack.pv_pa,
	    IRQ_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, abtstack.pv_va, abtstack.pv_pa,
	    ABT_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, undstack.pv_va, undstack.pv_pa,
	    UND_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, kernelstack.pv_va, kernelstack.pv_pa,
	    UPAGES * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

	pmap_map_chunk(l1pagetable, kernel_l1pt.pv_va, kernel_l1pt.pv_pa,
	    L1_TABLE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);

	for (loop = 0; loop < NUM_KERNEL_PTS; ++loop) {
		pmap_map_chunk(l1pagetable, kernel_pt_table[loop].pv_va,
		    kernel_pt_table[loop].pv_pa, L2_TABLE_SIZE,
		    VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);
	}

	/* Map the vector page. */
	pmap_map_entry(l1pagetable, ARM_VECTORS_HIGH, systempage.pv_pa,
	    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

#ifdef VERBOSE_INIT_ARM
	printf("systempage (vector page): p0x%08lx v0x%08lx\n",
	       systempage.pv_pa, vector_page);
#endif

	/* Map the statically mapped devices. */
	pmap_devmap_bootstrap(l1pagetable, ixm1200_devmap);

#ifdef VERBOSE_INIT_ARM
	printf("done.\n");
#endif

	/*
	 * Map the Dcache Flush page.
	 * Hw Ref Manual 3.2.4.5 Software Dcache Flush 
	 */
	pmap_map_chunk(l1pagetable, ixp12x0_cache_clean_addr, 0xe0000000,
	    CPU_IXP12X0_CACHE_CLEAN_SIZE, VM_PROT_READ, PTE_CACHE);

	/*
	 * Now we have the real page tables in place so we can switch to them.
	 * Once this is done we will be running with the REAL kernel page
	 * tables.
	 */

	/* Switch tables */
	cpu_domains((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT);
	cpu_setttb(kernel_l1pt.pv_pa, true);
	cpu_tlb_flushID();
	cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2));

	/*
	 * Moved here from cpu_startup() as data_abort_handler() references
	 * this during init
	 */
	uvm_lwp_setuarea(&lwp0, kernelstack.pv_va);

	/*
	 * We must now clean the cache again....
	 * Cleaning may be done by reading new data to displace any
	 * dirty data in the cache. This will have happened in cpu_setttb()
	 * but since we are boot strapping the addresses used for the read
	 * may have just been remapped and thus the cache could be out
	 * of sync. A re-clean after the switch will cure this.
	 * After booting there are no gross reloations of the kernel thus
	 * this problem will not occur after initarm().
	 */
	cpu_idcache_wbinv_all();

	arm32_vector_init(ARM_VECTORS_HIGH, ARM_VEC_ALL);

	/*
	 * Pages were allocated during the secondary bootstrap for the
	 * stacks for different CPU modes.
	 * We must now set the r13 registers in the different CPU modes to
	 * point to these stacks.
	 * Since the ARM stacks use STMFD etc. we must set r13 to the top end
	 * of the stack memory.
	 */
#ifdef VERBOSE_INIT_ARM
	printf("init subsystems: stacks ");
#endif

	set_stackptr(PSR_IRQ32_MODE,
	    irqstack.pv_va + IRQ_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_ABT32_MODE,
	    abtstack.pv_va + ABT_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_UND32_MODE,
	    undstack.pv_va + UND_STACK_SIZE * PAGE_SIZE);
#ifdef PMAP_DEBUG
	if (pmap_debug_level >= 0)
		printf("kstack V%08lx P%08lx\n", kernelstack.pv_va,
		    kernelstack.pv_pa);
#endif  /* PMAP_DEBUG */

	/*
	 * Well we should set a data abort handler.
	 * Once things get going this will change as we will need a proper
	 * handler. Until then we will use a handler that just panics but
	 * tells us why.
	 * Initialisation of the vetcors will just panic on a data abort.
	 * This just fills in a slightly better one.
	 */
#ifdef VERBOSE_INIT_ARM
	printf("vectors ");
#endif
	data_abort_handler_address = (u_int)data_abort_handler;
	prefetch_abort_handler_address = (u_int)prefetch_abort_handler;
	undefined_handler_address = (u_int)undefinedinstruction_bounce;
#ifdef VERBOSE_INIT_ARM
	printf("\ndata_abort_handler_address = %08x\n", data_abort_handler_address);
	printf("prefetch_abort_handler_address = %08x\n", prefetch_abort_handler_address);
	printf("undefined_handler_address = %08x\n", undefined_handler_address);
#endif

	/* Initialise the undefined instruction handlers */
#ifdef VERBOSE_INIT_ARM
	printf("undefined ");
#endif
	undefined_init();

	/* Load memory into UVM. */
#ifdef VERBOSE_INIT_ARM
	printf("page ");
#endif
	uvm_setpagesize();	/* initialize PAGE_SIZE-dependent variables */
	uvm_page_physload(atop(physical_freestart), atop(physical_freeend),
	    atop(physical_freestart), atop(physical_freeend),
	    VM_FREELIST_DEFAULT);

	/* Boot strap pmap telling it where the kernel page table is */
#ifdef VERBOSE_INIT_ARM
	printf("pmap ");
#endif
	pmap_bootstrap(KERNEL_VM_BASE, KERNEL_VM_BASE + KERNEL_VM_SIZE);

	/* Setup the IRQ system */
#ifdef VERBOSE_INIT_ARM
	printf("irq ");
#endif
	ixp12x0_intr_init();

#ifdef VERBOSE_INIT_ARM
	printf("done.\n");
#endif

#ifdef VERBOSE_INIT_ARM
	printf("freestart = 0x%08lx, free_pages = %d (0x%x)\n",
		physical_freestart, free_pages, free_pages);
	printf("freemempos=%08lx\n", freemempos);
	printf("switching to new L1 page table  @%#lx... \n", kernel_l1pt.pv_pa);
#endif

	consinit();
#ifdef VERBOSE_INIT_ARM
	printf("consinit \n");
#endif

	ixdp_ixp12x0_cc_setup();

#ifdef VERBOSE_INIT_ARM
	printf("bootstrap done.\n");
#endif

#if NKSYMS || defined(DDB) || defined(MODULAR)
	ksyms_addsyms_elf(symbolsize, ((int *)&end), ((char *)&end) + symbolsize);
#endif

#ifdef DDB
	db_machine_init();
	if (boothowto & RB_KDB)
		Debugger();
#endif

	/* We return the new stack pointer address */
	return(kernelstack.pv_va + USPACE_SVC_STACK_TOP);
}
コード例 #2
0
/*
 * It should be responsible for setting up everything that must be
 * in place when main is called.
 * This includes:
 *   Initializing the physical console so characters can be printed.
 *   Setting up page tables for the kernel.
 */
u_int
init_sa11x0(int argc, char **argv, struct bootinfo *bi)
{
	u_int kerneldatasize, symbolsize;
	u_int l1pagetable;
	vaddr_t freemempos;
	vsize_t pt_size;
	int loop;
#if NKSYMS || defined(DDB) || defined(MODULAR)
	Elf_Shdr *sh;
#endif

#ifdef DEBUG_BEFOREMMU
	/*
	 * At this point, we cannot call real consinit().
	 * Just call a faked up version of consinit(), which does the thing
	 * with MMU disabled.
	 */
	fakecninit();
#endif

	/*
	 * XXX for now, overwrite bootconfig to hardcoded values.
	 * XXX kill bootconfig and directly call uvm_physload
	 */
	bootconfig.dram[0].address = 0xc0000000;
	bootconfig.dram[0].pages = DRAM_PAGES;
	bootconfig.dramblocks = 1;

	kerneldatasize = (uint32_t)&end - (uint32_t)KERNEL_TEXT_BASE;
	symbolsize = 0;
#if NKSYMS || defined(DDB) || defined(MODULAR)
	if (!memcmp(&end, "\177ELF", 4)) {
		sh = (Elf_Shdr *)((char *)&end + ((Elf_Ehdr *)&end)->e_shoff);
		loop = ((Elf_Ehdr *)&end)->e_shnum;
		for (; loop; loop--, sh++)
			if (sh->sh_offset > 0 &&
			    (sh->sh_offset + sh->sh_size) > symbolsize)
				symbolsize = sh->sh_offset + sh->sh_size;
	}
#endif

	printf("kernsize=0x%x\n", kerneldatasize);
	kerneldatasize += symbolsize;
	kerneldatasize = ((kerneldatasize - 1) & ~(PAGE_SIZE * 4 - 1)) +
	    PAGE_SIZE * 8;

	/*
	 * hpcboot has loaded me with MMU disabled.
	 * So create kernel page tables and enable MMU.
	 */

	/*
	 * Set up the variables that define the availability of physcial
	 * memory.
	 */
	physical_start = bootconfig.dram[0].address;
	physical_freestart = physical_start
	    + (KERNEL_TEXT_BASE - KERNEL_BASE) + kerneldatasize;
	physical_end = bootconfig.dram[bootconfig.dramblocks - 1].address
	    + bootconfig.dram[bootconfig.dramblocks - 1].pages * PAGE_SIZE;
	physical_freeend = physical_end;
    
	for (loop = 0; loop < bootconfig.dramblocks; ++loop)
		physmem += bootconfig.dram[loop].pages;
    
	/* XXX handle UMA framebuffer memory */

	/* Use the first 256kB to allocate things */
	freemempos = KERNEL_BASE;
	memset((void *)KERNEL_BASE, 0, KERNEL_TEXT_BASE - KERNEL_BASE);

	/*
	 * Right. We have the bottom meg of memory mapped to 0x00000000
	 * so was can get at it. The kernel will occupy the start of it.
	 * After the kernel/args we allocate some of the fixed page tables
	 * we need to get the system going.
	 * We allocate one page directory and NUM_KERNEL_PTS page tables
	 * and store the physical addresses in the kernel_pt_table array.
	 * Must remember that neither the page L1 or L2 page tables are the
	 * same size as a page !
	 *
	 * Ok, the next bit of physical allocate may look complex but it is
	 * simple really. I have done it like this so that no memory gets
	 * wasted during the allocate of various pages and tables that are
	 * all different sizes.
	 * The start address will be page aligned.
	 * We allocate the kernel page directory on the first free 16KB
	 * boundary we find.
	 * We allocate the kernel page tables on the first 1KB boundary we
	 * find.  We allocate at least 9 PT's (12 currently).  This means
	 * that in the process we KNOW that we will encounter at least one
	 * 16KB boundary.
	 *
	 * Eventually if the top end of the memory gets used for process L1
	 * page tables the kernel L1 page table may be moved up there.
	 */

#ifdef VERBOSE_INIT_ARM
	printf("Allocating page tables\n");
#endif

	/* Define a macro to simplify memory allocation */
#define	valloc_pages(var, np)			\
	alloc_pages((var).pv_pa, (np));		\
	(var).pv_va = KERNEL_BASE + (var).pv_pa - physical_start;
#define	alloc_pages(var, np)			\
	(var) = freemempos;			\
	freemempos += (np) * PAGE_SIZE;

	valloc_pages(kernel_l1pt, L1_TABLE_SIZE / PAGE_SIZE);
	for (loop = 0; loop < NUM_KERNEL_PTS; ++loop) {
		alloc_pages(kernel_pt_table[loop].pv_pa,
		    L2_TABLE_SIZE / PAGE_SIZE);
		kernel_pt_table[loop].pv_va = kernel_pt_table[loop].pv_pa;
	}

	/* This should never be able to happen but better confirm that. */
	if (!kernel_l1pt.pv_pa || (kernel_l1pt.pv_pa & (L1_TABLE_SIZE-1)) != 0)
		panic("initarm: Failed to align the kernel page directory");

	/*
	 * Allocate a page for the system page mapped to V0x00000000
	 * This page will just contain the system vectors and can be
	 * shared by all processes.
	 */
	valloc_pages(systempage, 1);

	pt_size = round_page(freemempos) - physical_start;

	/* Allocate stacks for all modes */
	valloc_pages(irqstack, IRQ_STACK_SIZE);
	valloc_pages(abtstack, ABT_STACK_SIZE);
	valloc_pages(undstack, UND_STACK_SIZE);
	valloc_pages(kernelstack, UPAGES);

#ifdef VERBOSE_INIT_ARM
	printf("IRQ stack: p0x%08lx v0x%08lx\n", irqstack.pv_pa,
	    irqstack.pv_va); 
	printf("ABT stack: p0x%08lx v0x%08lx\n", abtstack.pv_pa,
	    abtstack.pv_va); 
	printf("UND stack: p0x%08lx v0x%08lx\n", undstack.pv_pa,
	    undstack.pv_va); 
	printf("SVC stack: p0x%08lx v0x%08lx\n", kernelstack.pv_pa,
	    kernelstack.pv_va); 
#endif

	alloc_pages(msgbufphys, round_page(MSGBUFSIZE) / PAGE_SIZE);

	/*
	 * XXX Actually, we only need virtual space and don't need
	 * XXX physical memory for sa110_cc_base and sa11x0_idle_mem.
	 */
	/*
	 * XXX totally stuffed hack to work round problems introduced
	 * in recent versions of the pmap code. Due to the calls used there
	 * we cannot allocate virtual memory during bootstrap.
	 */
	for (;;) {
		alloc_pages(sa1_cc_base, 1);
		if (!(sa1_cc_base & (CPU_SA110_CACHE_CLEAN_SIZE - 1)))
			break;
	}
	alloc_pages(sa1_cache_clean_addr, CPU_SA110_CACHE_CLEAN_SIZE / PAGE_SIZE - 1);

	sa1_cache_clean_addr = sa1_cc_base;
	sa1_cache_clean_size = CPU_SA110_CACHE_CLEAN_SIZE / 2;

	alloc_pages(sa11x0_idle_mem, 1);

	/*
	 * Ok, we have allocated physical pages for the primary kernel
	 * page tables.
	 */

#ifdef VERBOSE_INIT_ARM
	printf("Creating L1 page table\n");
#endif

	/*
	 * Now we start construction of the L1 page table.
	 * We start by mapping the L2 page tables into the L1.
	 * This means that we can replace L1 mappings later on if necessary.
	 */
	l1pagetable = kernel_l1pt.pv_pa;

	/* Map the L2 pages tables in the L1 page table */
	pmap_link_l2pt(l1pagetable, 0x00000000,
	    &kernel_pt_table[KERNEL_PT_SYS]);
#define SAIPIO_BASE		0xd0000000		/* XXX XXX */
	pmap_link_l2pt(l1pagetable, SAIPIO_BASE,
	    &kernel_pt_table[KERNEL_PT_IO]);
	for (loop = 0; loop < KERNEL_PT_KERNEL_NUM; ++loop)
		pmap_link_l2pt(l1pagetable, KERNEL_BASE + loop * 0x00400000,
		    &kernel_pt_table[KERNEL_PT_KERNEL + loop]);
	for (loop = 0; loop < KERNEL_PT_VMDATA_NUM; ++loop)
		pmap_link_l2pt(l1pagetable, KERNEL_VM_BASE + loop * 0x00400000,
		    &kernel_pt_table[KERNEL_PT_VMDATA + loop]);

	/* update the top of the kernel VM */
	pmap_curmaxkvaddr =
	    KERNEL_VM_BASE + (KERNEL_PT_VMDATA_NUM * 0x00400000);

#ifdef VERBOSE_INIT_ARM
	printf("Mapping kernel\n");
#endif

	/* Now we fill in the L2 pagetable for the kernel code/data */

	/*
	 * XXX there is no ELF header to find RO region.
	 * XXX What should we do?
	 */
#if 0
	if (N_GETMAGIC(kernexec[0]) == ZMAGIC) {
		logical = pmap_map_chunk(l1pagetable, KERNEL_TEXT_BASE,
		    physical_start, kernexec->a_text,
		    VM_PROT_READ, PTE_CACHE);
		logical += pmap_map_chunk(l1pagetable,
		    KERNEL_TEXT_BASE + logical, physical_start + logical,
		    kerneldatasize - kernexec->a_text,
		    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	} else
#endif
		pmap_map_chunk(l1pagetable, KERNEL_TEXT_BASE,
		    KERNEL_TEXT_BASE - KERNEL_BASE + physical_start,
		    kerneldatasize, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

#ifdef VERBOSE_INIT_ARM
	printf("Constructing L2 page tables\n");
#endif

	/* Map the stack pages */
	pmap_map_chunk(l1pagetable, irqstack.pv_va, irqstack.pv_pa,
	    IRQ_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, abtstack.pv_va, abtstack.pv_pa,
	    ABT_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, undstack.pv_va, undstack.pv_pa,
	    UND_STACK_SIZE * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);
	pmap_map_chunk(l1pagetable, kernelstack.pv_va, kernelstack.pv_pa,
	    UPAGES * PAGE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

	pmap_map_chunk(l1pagetable, kernel_l1pt.pv_va, kernel_l1pt.pv_pa,
	    L1_TABLE_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);

	/* Map page tables */
	pmap_map_chunk(l1pagetable, KERNEL_BASE, physical_start, pt_size,
	    VM_PROT_READ|VM_PROT_WRITE, PTE_PAGETABLE);

	/* Map a page for entering idle mode */
	pmap_map_entry(l1pagetable, sa11x0_idle_mem, sa11x0_idle_mem,
	    VM_PROT_READ|VM_PROT_WRITE, PTE_NOCACHE);

	/* Map the vector page. */
	pmap_map_entry(l1pagetable, vector_page, systempage.pv_pa,
	    VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

	/* Map the statically mapped devices. */
	pmap_devmap_bootstrap(l1pagetable, sa11x0_devmap);

	pmap_map_chunk(l1pagetable, sa1_cache_clean_addr, 0xe0000000,
	    CPU_SA110_CACHE_CLEAN_SIZE, VM_PROT_READ|VM_PROT_WRITE, PTE_CACHE);

	/*
	 * Now we have the real page tables in place so we can switch to them.
	 * Once this is done we will be running with the REAL kernel page
	 * tables.
	 */

#ifdef VERBOSE_INIT_ARM
	printf("done.\n");
#endif

	/*
	 * Pages were allocated during the secondary bootstrap for the
	 * stacks for different CPU modes.
	 * We must now set the r13 registers in the different CPU modes to
	 * point to these stacks.
	 * Since the ARM stacks use STMFD etc. we must set r13 to the top end
	 * of the stack memory.
	 */
#ifdef VERBOSE_INIT_ARM
	printf("init subsystems: stacks ");
#endif

	set_stackptr(PSR_IRQ32_MODE,
	    irqstack.pv_va + IRQ_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_ABT32_MODE,
	    abtstack.pv_va + ABT_STACK_SIZE * PAGE_SIZE);
	set_stackptr(PSR_UND32_MODE,
	    undstack.pv_va + UND_STACK_SIZE * PAGE_SIZE);
#ifdef PMAP_DEBUG
	if (pmap_debug_level >= 0)
		printf("kstack V%08lx P%08lx\n", kernelstack.pv_va,
		    kernelstack.pv_pa);
#endif /* PMAP_DEBUG */

	/*
	 * Well we should set a data abort handler.
	 * Once things get going this will change as we will need a proper
	 * handler. Until then we will use a handler that just panics but
	 * tells us why.
	 * Initialization of the vectors will just panic on a data abort.
	 * This just fills in a slightly better one.
	 */
#ifdef VERBOSE_INIT_ARM
	printf("vectors ");
#endif
	data_abort_handler_address = (u_int)data_abort_handler;
	prefetch_abort_handler_address = (u_int)prefetch_abort_handler;
	undefined_handler_address = (u_int)undefinedinstruction_bounce;
#ifdef DEBUG
	printf("%08x %08x %08x\n", data_abort_handler_address,
	    prefetch_abort_handler_address, undefined_handler_address); 
#endif

	/* Initialize the undefined instruction handlers */
#ifdef VERBOSE_INIT_ARM
	printf("undefined\n");
#endif
	undefined_init();

	/* Set the page table address. */
#ifdef VERBOSE_INIT_ARM
	printf("switching to new L1 page table  @%#lx...\n", kernel_l1pt.pv_pa);
#endif
	cpu_domains((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT);
	cpu_setttb(kernel_l1pt.pv_pa, true);
	cpu_tlb_flushID();
	cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2));

	/*
	 * Moved from cpu_startup() as data_abort_handler() references
	 * this during uvm init.
	 */
	uvm_lwp_setuarea(&lwp0, kernelstack.pv_va);

#ifdef BOOT_DUMP
	dumppages((char *)0xc0000000, 16 * PAGE_SIZE);
	dumppages((char *)0xb0100000, 64); /* XXX */
#endif
	/* Enable MMU, I-cache, D-cache, write buffer. */
	cpufunc_control(0x337f, 0x107d);

	arm32_vector_init(ARM_VECTORS_LOW, ARM_VEC_ALL);

	consinit();

#ifdef VERBOSE_INIT_ARM
	printf("bootstrap done.\n");
#endif

#ifdef VERBOSE_INIT_ARM
	printf("freemempos=%08lx\n", freemempos);
	printf("MMU enabled. control=%08x\n", cpu_get_control());
#endif

	/* Load memory into UVM. */
	uvm_setpagesize();	/* initialize PAGE_SIZE-dependent variables */
	for (loop = 0; loop < bootconfig.dramblocks; loop++) {
		paddr_t dblk_start = (paddr_t)bootconfig.dram[loop].address;
		paddr_t dblk_end = dblk_start
			+ (bootconfig.dram[loop].pages * PAGE_SIZE);

		if (dblk_start < physical_freestart)
			dblk_start = physical_freestart;
		if (dblk_end > physical_freeend)
			dblk_end = physical_freeend;

		uvm_page_physload(atop(dblk_start), atop(dblk_end),
		    atop(dblk_start), atop(dblk_end), VM_FREELIST_DEFAULT);
	}

	/* Boot strap pmap telling it where the kernel page table is */
	pmap_bootstrap(KERNEL_VM_BASE, KERNEL_VM_BASE + KERNEL_VM_SIZE);

#ifdef BOOT_DUMP
	dumppages((char *)kernel_l1pt.pv_va, 16);
#endif

#ifdef DDB
	db_machine_init();
#endif
#if NKSYMS || defined(DDB) || defined(MODULAR)
	ksyms_addsyms_elf(symbolsize, ((int *)&end), ((char *)&end) + symbolsize);
#endif

	printf("kernsize=0x%x", kerneldatasize);
	printf(" (including 0x%x symbols)\n", symbolsize);

#ifdef DDB
	if (boothowto & RB_KDB)
		Debugger();
#endif /* DDB */

	/* We return the new stack pointer address */
	return (kernelstack.pv_va + USPACE_SVC_STACK_TOP);
}