prom_init.c

LINUX 2.6.17.4的源码

 		/* skip "name" */
 		if (strcmp(RELOC(pname), RELOC("name")) == 0) {
 			prev_name = RELOC("name");
 			continue;
 		}

		/* find string offset */
		soff = dt_find_string(RELOC(pname));
		if (soff == 0) {
			prom_printf("WARNING: Can't find string index for"
				    " <%s>, node %s\n", RELOC(pname), path);
			break;
		}
		prev_name = sstart + soff;

		/* get length */
		l = call_prom("getproplen", 2, 1, node, RELOC(pname));

		/* sanity checks */
		if (l == PROM_ERROR)
			continue;
		if (l > MAX_PROPERTY_LENGTH) {
			prom_printf("WARNING: ignoring large property ");
			/* It seems OF doesn't null-terminate the path :-( */
			prom_printf("[%s] ", path);
			prom_printf("%s length 0x%x\n", RELOC(pname), l);
			continue;
		}

		/* push property head */
		dt_push_token(OF_DT_PROP, mem_start, mem_end);
		dt_push_token(l, mem_start, mem_end);
		dt_push_token(soff, mem_start, mem_end);

		/* push property content */
		valp = make_room(mem_start, mem_end, l, 4);
		call_prom("getprop", 4, 1, node, RELOC(pname), valp, l);
		*mem_start = _ALIGN(*mem_start, 4);
	}

	/* Add a "linux,phandle" property. */
	soff = dt_find_string(RELOC("linux,phandle"));
	if (soff == 0)
		prom_printf("WARNING: Can't find string index for"
			    " <linux-phandle> node %s\n", path);
	else {
		dt_push_token(OF_DT_PROP, mem_start, mem_end);
		dt_push_token(4, mem_start, mem_end);
		dt_push_token(soff, mem_start, mem_end);
		valp = make_room(mem_start, mem_end, 4, 4);
		*(u32 *)valp = node;
	}

	/* do all our children */
	child = call_prom("child", 1, 1, node);
	while (child != 0) {
		scan_dt_build_struct(child, mem_start, mem_end);
		child = call_prom("peer", 1, 1, child);
	}

	dt_push_token(OF_DT_END_NODE, mem_start, mem_end);
}

static void __init flatten_device_tree(void)
{
	phandle root;
	unsigned long mem_start, mem_end, room;
	struct boot_param_header *hdr;
	struct prom_t *_prom = &RELOC(prom);
	char *namep;
	u64 *rsvmap;

	/*
	 * Check how much room we have between alloc top & bottom (+/- a
	 * few pages), crop to 4Mb, as this is our "chuck" size
	 */
	room = RELOC(alloc_top) - RELOC(alloc_bottom) - 0x4000;
	if (room > DEVTREE_CHUNK_SIZE)
		room = DEVTREE_CHUNK_SIZE;
	prom_debug("starting device tree allocs at %x\n", RELOC(alloc_bottom));

	/* Now try to claim that */
	mem_start = (unsigned long)alloc_up(room, PAGE_SIZE);
	if (mem_start == 0)
		prom_panic("Can't allocate initial device-tree chunk\n");
	mem_end = RELOC(alloc_top);

	/* Get root of tree */
	root = call_prom("peer", 1, 1, (phandle)0);
	if (root == (phandle)0)
		prom_panic ("couldn't get device tree root\n");

	/* Build header and make room for mem rsv map */ 
	mem_start = _ALIGN(mem_start, 4);
	hdr = make_room(&mem_start, &mem_end,
			sizeof(struct boot_param_header), 4);
	RELOC(dt_header_start) = (unsigned long)hdr;
	rsvmap = make_room(&mem_start, &mem_end, sizeof(mem_reserve_map), 8);

	/* Start of strings */
	mem_start = PAGE_ALIGN(mem_start);
	RELOC(dt_string_start) = mem_start;
	mem_start += 4; /* hole */

	/* Add "linux,phandle" in there, we'll need it */
	namep = make_room(&mem_start, &mem_end, 16, 1);
	strcpy(namep, RELOC("linux,phandle"));
	mem_start = (unsigned long)namep + strlen(namep) + 1;

	/* Build string array */
	prom_printf("Building dt strings...\n"); 
	scan_dt_build_strings(root, &mem_start, &mem_end);
	RELOC(dt_string_end) = mem_start;

	/* Build structure */
	mem_start = PAGE_ALIGN(mem_start);
	RELOC(dt_struct_start) = mem_start;
	prom_printf("Building dt structure...\n"); 
	scan_dt_build_struct(root, &mem_start, &mem_end);
	dt_push_token(OF_DT_END, &mem_start, &mem_end);
	RELOC(dt_struct_end) = PAGE_ALIGN(mem_start);

	/* Finish header */
	hdr->boot_cpuid_phys = _prom->cpu;
	hdr->magic = OF_DT_HEADER;
	hdr->totalsize = RELOC(dt_struct_end) - RELOC(dt_header_start);
	hdr->off_dt_struct = RELOC(dt_struct_start) - RELOC(dt_header_start);
	hdr->off_dt_strings = RELOC(dt_string_start) - RELOC(dt_header_start);
	hdr->dt_strings_size = RELOC(dt_string_end) - RELOC(dt_string_start);
	hdr->off_mem_rsvmap = ((unsigned long)rsvmap) - RELOC(dt_header_start);
	hdr->version = OF_DT_VERSION;
	/* Version 16 is not backward compatible */
	hdr->last_comp_version = 0x10;

	/* Reserve the whole thing and copy the reserve map in, we
	 * also bump mem_reserve_cnt to cause further reservations to
	 * fail since it's too late.
	 */
	reserve_mem(RELOC(dt_header_start), hdr->totalsize);
	memcpy(rsvmap, RELOC(mem_reserve_map), sizeof(mem_reserve_map));

#ifdef DEBUG_PROM
	{
		int i;
		prom_printf("reserved memory map:\n");
		for (i = 0; i < RELOC(mem_reserve_cnt); i++)
			prom_printf("  %x - %x\n",
				    RELOC(mem_reserve_map)[i].base,
				    RELOC(mem_reserve_map)[i].size);
	}
#endif
	RELOC(mem_reserve_cnt) = MEM_RESERVE_MAP_SIZE;

	prom_printf("Device tree strings 0x%x -> 0x%x\n",
		    RELOC(dt_string_start), RELOC(dt_string_end)); 
	prom_printf("Device tree struct  0x%x -> 0x%x\n",
		    RELOC(dt_struct_start), RELOC(dt_struct_end));

}

#ifdef CONFIG_PPC_MAPLE
/* PIBS Version 1.05.0000 04/26/2005 has an incorrect /ht/isa/ranges property.
 * The values are bad, and it doesn't even have the right number of cells. */
static void __init fixup_device_tree_maple(void)
{
	phandle isa;
	u32 isa_ranges[6];

	isa = call_prom("finddevice", 1, 1, ADDR("/ht@0/isa@4"));
	if (!PHANDLE_VALID(isa))
		return;

	if (prom_getprop(isa, "ranges", isa_ranges, sizeof(isa_ranges))
		== PROM_ERROR)
		return;

	if (isa_ranges[0] != 0x1 ||
		isa_ranges[1] != 0xf4000000 ||
		isa_ranges[2] != 0x00010000)
		return;

	prom_printf("fixing up bogus ISA range on Maple...\n");

	isa_ranges[0] = 0x1;
	isa_ranges[1] = 0x0;
	isa_ranges[2] = 0x01002000; /* IO space; PCI device = 4 */
	isa_ranges[3] = 0x0;
	isa_ranges[4] = 0x0;
	isa_ranges[5] = 0x00010000;
	prom_setprop(isa, "/ht@0/isa@4", "ranges",
			isa_ranges, sizeof(isa_ranges));
}
#else
#define fixup_device_tree_maple()
#endif

#if defined(CONFIG_PPC64) && defined(CONFIG_PPC_PMAC)
static void __init fixup_device_tree_pmac(void)
{
	phandle u3, i2c, mpic;
	u32 u3_rev;
	u32 interrupts[2];
	u32 parent;

	/* Some G5s have a missing interrupt definition, fix it up here */
	u3 = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000"));
	if (!PHANDLE_VALID(u3))
		return;
	i2c = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/i2c@f8001000"));
	if (!PHANDLE_VALID(i2c))
		return;
	mpic = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/mpic@f8040000"));
	if (!PHANDLE_VALID(mpic))
		return;

	/* check if proper rev of u3 */
	if (prom_getprop(u3, "device-rev", &u3_rev, sizeof(u3_rev))
	    == PROM_ERROR)
		return;
	if (u3_rev < 0x35 || u3_rev > 0x39)
		return;
	/* does it need fixup ? */
	if (prom_getproplen(i2c, "interrupts") > 0)
		return;

	prom_printf("fixing up bogus interrupts for u3 i2c...\n");

	/* interrupt on this revision of u3 is number 0 and level */
	interrupts[0] = 0;
	interrupts[1] = 1;
	prom_setprop(i2c, "/u3@0,f8000000/i2c@f8001000", "interrupts",
		     &interrupts, sizeof(interrupts));
	parent = (u32)mpic;
	prom_setprop(i2c, "/u3@0,f8000000/i2c@f8001000", "interrupt-parent",
		     &parent, sizeof(parent));
}
#else
#define fixup_device_tree_pmac()
#endif

static void __init fixup_device_tree(void)
{
	fixup_device_tree_maple();
	fixup_device_tree_pmac();
}

static void __init prom_find_boot_cpu(void)
{
       	struct prom_t *_prom = &RELOC(prom);
	u32 getprop_rval;
	ihandle prom_cpu;
	phandle cpu_pkg;

	_prom->cpu = 0;
	if (prom_getprop(_prom->chosen, "cpu", &prom_cpu, sizeof(prom_cpu)) <= 0)
		return;

	cpu_pkg = call_prom("instance-to-package", 1, 1, prom_cpu);

	prom_getprop(cpu_pkg, "reg", &getprop_rval, sizeof(getprop_rval));
	_prom->cpu = getprop_rval;

	prom_debug("Booting CPU hw index = 0x%x\n", _prom->cpu);
}

static void __init prom_check_initrd(unsigned long r3, unsigned long r4)
{
#ifdef CONFIG_BLK_DEV_INITRD
       	struct prom_t *_prom = &RELOC(prom);

	if (r3 && r4 && r4 != 0xdeadbeef) {
		unsigned long val;

		RELOC(prom_initrd_start) = is_kernel_addr(r3) ? __pa(r3) : r3;
		RELOC(prom_initrd_end) = RELOC(prom_initrd_start) + r4;

		val = RELOC(prom_initrd_start);
		prom_setprop(_prom->chosen, "/chosen", "linux,initrd-start",
			     &val, sizeof(val));
		val = RELOC(prom_initrd_end);
		prom_setprop(_prom->chosen, "/chosen", "linux,initrd-end",
			     &val, sizeof(val));

		reserve_mem(RELOC(prom_initrd_start),
			    RELOC(prom_initrd_end) - RELOC(prom_initrd_start));

		prom_debug("initrd_start=0x%x\n", RELOC(prom_initrd_start));
		prom_debug("initrd_end=0x%x\n", RELOC(prom_initrd_end));
	}
#endif /* CONFIG_BLK_DEV_INITRD */
}

/*
 * We enter here early on, when the Open Firmware prom is still
 * handling exceptions and the MMU hash table for us.
 */

unsigned long __init prom_init(unsigned long r3, unsigned long r4,
			       unsigned long pp,
			       unsigned long r6, unsigned long r7)
{	
       	struct prom_t *_prom;
	unsigned long hdr;
	unsigned long offset = reloc_offset();

#ifdef CONFIG_PPC32
	reloc_got2(offset);
#endif

	_prom = &RELOC(prom);

	/*
	 * First zero the BSS
	 */
	memset(&RELOC(__bss_start), 0, __bss_stop - __bss_start);

	/*
	 * Init interface to Open Firmware, get some node references,
	 * like /chosen
	 */
	prom_init_client_services(pp);

	/*
	 * See if this OF is old enough that we need to do explicit maps
	 * and other workarounds
	 */
	prom_find_mmu();

	/*
	 * Init prom stdout device
	 */
	prom_init_stdout();

	/*
	 * Get default machine type. At this point, we do not differentiate
	 * between pSeries SMP and pSeries LPAR
	 */
	RELOC(of_platform) = prom_find_machine_type();

	/* Bail if this is a kdump kernel. */
	if (PHYSICAL_START > 0)
		prom_panic("Error: You can't boot a kdump kernel from OF!\n");

	/*
	 * Check for an initrd
	 */
	prom_check_initrd(r3, r4);

#ifdef CONFIG_PPC_PSERIES
	/*
	 * On pSeries, inform the firmware about our capabilities
	 */
	if (RELOC(of_platform) == PLATFORM_PSERIES ||
	    RELOC(of_platform) == PLATFORM_PSERIES_LPAR)
		prom_send_capabilities();
#endif

	/*
	 * Copy the CPU hold code
	 */
       	if (RELOC(of_platform) != PLATFORM_POWERMAC)
       		copy_and_flush(0, KERNELBASE + offset, 0x100, 0);

	/*
	 * Do early parsing of command line
	 */
	early_cmdline_parse();

	/*
	 * Initialize memory management within prom_init
	 */
	prom_init_mem();

#ifdef CONFIG_KEXEC
	if (RELOC(prom_crashk_base))
		reserve_mem(RELOC(prom_crashk_base), RELOC(prom_crashk_size));
#endif
	/*
	 * Determine which cpu is actually running right _now_
	 */
	prom_find_boot_cpu();

	/* 
	 * Initialize display devices
	 */
	prom_check_displays();

#ifdef CONFIG_PPC64
	/*
	 * Initialize IOMMU (TCE tables) on pSeries. Do that before anything else
	 * that uses the allocator, we need to make sure we get the top of memory
	 * available for us here...
	 */
	if (RELOC(of_platform) == PLATFORM_PSERIES)
		prom_initialize_tce_table();
#endif

	/*
	 * On non-powermacs, try to instantiate RTAS and puts all CPUs
	 * in spin-loops. PowerMacs don't have a working RTAS and use
	 * a different way to spin CPUs
	 */
	if (RELOC(of_platform) != PLATFORM_POWERMAC) {
		prom_instantiate_rtas();
		prom_hold_cpus();
	}

	/*
	 * Fill in some infos for use by the kernel later on
	 */
	if (RELOC(prom_memory_limit))
		prom_setprop(_prom->chosen, "/chosen", "linux,memory-limit",
			     &RELOC(prom_memory_limit),
			     sizeof(prom_memory_limit));
#ifdef CONFIG_PPC64
	if (RELOC(ppc64_iommu_off))
		prom_setprop(_prom->chosen, "/chosen", "linux,iommu-off",
			     NULL, 0);

	if (RELOC(iommu_force_on))
		prom_setprop(_prom->chosen, "/chosen", "linux,iommu-force-on",
			     NULL, 0);

	if (RELOC(prom_tce_alloc_start)) {
		prom_setprop(_prom->chosen, "/chosen", "linux,tce-alloc-start",
			     &RELOC(prom_tce_alloc_start),
			     sizeof(prom_tce_alloc_start));
		prom_setprop(_prom->chosen, "/chosen", "linux,tce-alloc-end",
			     &RELOC(prom_tce_alloc_end),
			     sizeof(prom_tce_alloc_end));
	}
#endif

#ifdef CONFIG_KEXEC
	if (RELOC(prom_crashk_base)) {
		prom_setprop(_prom->chosen, "/chosen", "linux,crashkernel-base",
			PTRRELOC(&prom_crashk_base),
			sizeof(RELOC(prom_crashk_base)));
		prom_setprop(_prom->chosen, "/chosen", "linux,crashkernel-size",
			PTRRELOC(&prom_crashk_size),
			sizeof(RELOC(prom_crashk_size)));
	}
#endif
	/*
	 * Fixup any known bugs in the device-tree
	 */
	fixup_device_tree();

	/*
	 * Now finally create the flattened device-tree
	 */
	prom_printf("copying OF device tree ...\n");
	flatten_device_tree();

	/*
	 * in case stdin is USB and still active on IBM machines...
	 * Unfortunately quiesce crashes on some powermacs if we have
	 * closed stdin already (in particular the powerbook 101).
	 */
	if (RELOC(of_platform) != PLATFORM_POWERMAC)
		prom_close_stdin();

	/*
	 * Call OF "quiesce" method to shut down pending DMA's from
	 * devices etc...
	 */
	prom_printf("Calling quiesce ...\n");
	call_prom("quiesce", 0, 0);

	/*
	 * And finally, call the kernel passing it the flattened device
	 * tree and NULL as r5, thus triggering the new entry point which
	 * is commo