prom_init.c

linux 内核源代码

			/* Primary Thread of non-boot cpu */
			prom_printf("%x : starting cpu hw idx %x... ", cpuid, reg);
			call_prom("start-cpu", 3, 0, node,
				  secondary_hold, reg);

			for (i = 0; (i < 100000000) && 
			     (*acknowledge == ((unsigned long)-1)); i++ )
				mb();

			if (*acknowledge == reg)
				prom_printf("done\n");
			else
				prom_printf("failed: %x\n", *acknowledge);
		}
#ifdef CONFIG_SMP
		else
			prom_printf("%x : boot cpu     %x\n", cpuid, reg);
#endif /* CONFIG_SMP */

		/* Reserve cpu #s for secondary threads.   They start later. */
		cpuid += cpu_threads;
	}

	if (cpuid > NR_CPUS)
		prom_printf("WARNING: maximum CPUs (" __stringify(NR_CPUS)
			    ") exceeded: ignoring extras\n");

	prom_debug("prom_hold_cpus: end...\n");
}


static void __init prom_init_client_services(unsigned long pp)
{
	struct prom_t *_prom = &RELOC(prom);

	/* Get a handle to the prom entry point before anything else */
	RELOC(prom_entry) = pp;

	/* get a handle for the stdout device */
	_prom->chosen = call_prom("finddevice", 1, 1, ADDR("/chosen"));
	if (!PHANDLE_VALID(_prom->chosen))
		prom_panic("cannot find chosen"); /* msg won't be printed :( */

	/* get device tree root */
	_prom->root = call_prom("finddevice", 1, 1, ADDR("/"));
	if (!PHANDLE_VALID(_prom->root))
		prom_panic("cannot find device tree root"); /* msg won't be printed :( */

	_prom->mmumap = 0;
}

#ifdef CONFIG_PPC32
/*
 * For really old powermacs, we need to map things we claim.
 * For that, we need the ihandle of the mmu.
 * Also, on the longtrail, we need to work around other bugs.
 */
static void __init prom_find_mmu(void)
{
	struct prom_t *_prom = &RELOC(prom);
	phandle oprom;
	char version[64];

	oprom = call_prom("finddevice", 1, 1, ADDR("/openprom"));
	if (!PHANDLE_VALID(oprom))
		return;
	if (prom_getprop(oprom, "model", version, sizeof(version)) <= 0)
		return;
	version[sizeof(version) - 1] = 0;
	/* XXX might need to add other versions here */
	if (strcmp(version, "Open Firmware, 1.0.5") == 0)
		of_workarounds = OF_WA_CLAIM;
	else if (strncmp(version, "FirmWorks,3.", 12) == 0) {
		of_workarounds = OF_WA_CLAIM | OF_WA_LONGTRAIL;
		call_prom("interpret", 1, 1, "dev /memory 0 to allow-reclaim");
	} else
		return;
	_prom->memory = call_prom("open", 1, 1, ADDR("/memory"));
	prom_getprop(_prom->chosen, "mmu", &_prom->mmumap,
		     sizeof(_prom->mmumap));
	if (!IHANDLE_VALID(_prom->memory) || !IHANDLE_VALID(_prom->mmumap))
		of_workarounds &= ~OF_WA_CLAIM;		/* hmmm */
}
#else
#define prom_find_mmu()
#endif

static void __init prom_init_stdout(void)
{
	struct prom_t *_prom = &RELOC(prom);
	char *path = RELOC(of_stdout_device);
	char type[16];
	u32 val;

	if (prom_getprop(_prom->chosen, "stdout", &val, sizeof(val)) <= 0)
		prom_panic("cannot find stdout");

	_prom->stdout = val;

	/* Get the full OF pathname of the stdout device */
	memset(path, 0, 256);
	call_prom("instance-to-path", 3, 1, _prom->stdout, path, 255);
	val = call_prom("instance-to-package", 1, 1, _prom->stdout);
	prom_setprop(_prom->chosen, "/chosen", "linux,stdout-package",
		     &val, sizeof(val));
	prom_printf("OF stdout device is: %s\n", RELOC(of_stdout_device));
	prom_setprop(_prom->chosen, "/chosen", "linux,stdout-path",
		     path, strlen(path) + 1);

	/* If it's a display, note it */
	memset(type, 0, sizeof(type));
	prom_getprop(val, "device_type", type, sizeof(type));
	if (strcmp(type, RELOC("display")) == 0)
		prom_setprop(val, path, "linux,boot-display", NULL, 0);
}

static void __init prom_close_stdin(void)
{
	struct prom_t *_prom = &RELOC(prom);
	ihandle val;

	if (prom_getprop(_prom->chosen, "stdin", &val, sizeof(val)) > 0)
		call_prom("close", 1, 0, val);
}

static int __init prom_find_machine_type(void)
{
	struct prom_t *_prom = &RELOC(prom);
	char compat[256];
	int len, i = 0;
#ifdef CONFIG_PPC64
	phandle rtas;
	int x;
#endif

	/* Look for a PowerMac */
	len = prom_getprop(_prom->root, "compatible",
			   compat, sizeof(compat)-1);
	if (len > 0) {
		compat[len] = 0;
		while (i < len) {
			char *p = &compat[i];
			int sl = strlen(p);
			if (sl == 0)
				break;
			if (strstr(p, RELOC("Power Macintosh")) ||
			    strstr(p, RELOC("MacRISC")))
				return PLATFORM_POWERMAC;
#ifdef CONFIG_PPC64
			/* We must make sure we don't detect the IBM Cell
			 * blades as pSeries due to some firmware issues,
			 * so we do it here.
			 */
			if (strstr(p, RELOC("IBM,CBEA")) ||
			    strstr(p, RELOC("IBM,CPBW-1.0")))
				return PLATFORM_GENERIC;
#endif /* CONFIG_PPC64 */
			i += sl + 1;
		}
	}
#ifdef CONFIG_PPC64
	/* If not a mac, try to figure out if it's an IBM pSeries or any other
	 * PAPR compliant platform. We assume it is if :
	 *  - /device_type is "chrp" (please, do NOT use that for future
	 *    non-IBM designs !
	 *  - it has /rtas
	 */
	len = prom_getprop(_prom->root, "device_type",
			   compat, sizeof(compat)-1);
	if (len <= 0)
		return PLATFORM_GENERIC;
	if (strcmp(compat, RELOC("chrp")))
		return PLATFORM_GENERIC;

	/* Default to pSeries. We need to know if we are running LPAR */
	rtas = call_prom("finddevice", 1, 1, ADDR("/rtas"));
	if (!PHANDLE_VALID(rtas))
		return PLATFORM_GENERIC;
	x = prom_getproplen(rtas, "ibm,hypertas-functions");
	if (x != PROM_ERROR) {
		prom_printf("Hypertas detected, assuming LPAR !\n");
		return PLATFORM_PSERIES_LPAR;
	}
	return PLATFORM_PSERIES;
#else
	return PLATFORM_GENERIC;
#endif
}

static int __init prom_set_color(ihandle ih, int i, int r, int g, int b)
{
	return call_prom("call-method", 6, 1, ADDR("color!"), ih, i, b, g, r);
}

/*
 * If we have a display that we don't know how to drive,
 * we will want to try to execute OF's open method for it
 * later.  However, OF will probably fall over if we do that
 * we've taken over the MMU.
 * So we check whether we will need to open the display,
 * and if so, open it now.
 */
static void __init prom_check_displays(void)
{
	char type[16], *path;
	phandle node;
	ihandle ih;
	int i;

	static unsigned char default_colors[] = {
		0x00, 0x00, 0x00,
		0x00, 0x00, 0xaa,
		0x00, 0xaa, 0x00,
		0x00, 0xaa, 0xaa,
		0xaa, 0x00, 0x00,
		0xaa, 0x00, 0xaa,
		0xaa, 0xaa, 0x00,
		0xaa, 0xaa, 0xaa,
		0x55, 0x55, 0x55,
		0x55, 0x55, 0xff,
		0x55, 0xff, 0x55,
		0x55, 0xff, 0xff,
		0xff, 0x55, 0x55,
		0xff, 0x55, 0xff,
		0xff, 0xff, 0x55,
		0xff, 0xff, 0xff
	};
	const unsigned char *clut;

	prom_printf("Looking for displays\n");
	for (node = 0; prom_next_node(&node); ) {
		memset(type, 0, sizeof(type));
		prom_getprop(node, "device_type", type, sizeof(type));
		if (strcmp(type, RELOC("display")) != 0)
			continue;

		/* It seems OF doesn't null-terminate the path :-( */
		path = RELOC(prom_scratch);
		memset(path, 0, PROM_SCRATCH_SIZE);

		/*
		 * leave some room at the end of the path for appending extra
		 * arguments
		 */
		if (call_prom("package-to-path", 3, 1, node, path,
			      PROM_SCRATCH_SIZE-10) == PROM_ERROR)
			continue;
		prom_printf("found display   : %s, opening ... ", path);
		
		ih = call_prom("open", 1, 1, path);
		if (ih == 0) {
			prom_printf("failed\n");
			continue;
		}

		/* Success */
		prom_printf("done\n");
		prom_setprop(node, path, "linux,opened", NULL, 0);

		/* Setup a usable color table when the appropriate
		 * method is available. Should update this to set-colors */
		clut = RELOC(default_colors);
		for (i = 0; i < 32; i++, clut += 3)
			if (prom_set_color(ih, i, clut[0], clut[1],
					   clut[2]) != 0)
				break;

#ifdef CONFIG_LOGO_LINUX_CLUT224
		clut = PTRRELOC(RELOC(logo_linux_clut224.clut));
		for (i = 0; i < RELOC(logo_linux_clut224.clutsize); i++, clut += 3)
			if (prom_set_color(ih, i + 32, clut[0], clut[1],
					   clut[2]) != 0)
				break;
#endif /* CONFIG_LOGO_LINUX_CLUT224 */
	}
}


/* Return (relocated) pointer to this much memory: moves initrd if reqd. */
static void __init *make_room(unsigned long *mem_start, unsigned long *mem_end,
			      unsigned long needed, unsigned long align)
{
	void *ret;

	*mem_start = _ALIGN(*mem_start, align);
	while ((*mem_start + needed) > *mem_end) {
		unsigned long room, chunk;

		prom_debug("Chunk exhausted, claiming more at %x...\n",
			   RELOC(alloc_bottom));
		room = RELOC(alloc_top) - RELOC(alloc_bottom);
		if (room > DEVTREE_CHUNK_SIZE)
			room = DEVTREE_CHUNK_SIZE;
		if (room < PAGE_SIZE)
			prom_panic("No memory for flatten_device_tree (no room)");
		chunk = alloc_up(room, 0);
		if (chunk == 0)
			prom_panic("No memory for flatten_device_tree (claim failed)");
		*mem_end = RELOC(alloc_top);
	}

	ret = (void *)*mem_start;
	*mem_start += needed;

	return ret;
}

#define dt_push_token(token, mem_start, mem_end) \
	do { *((u32 *)make_room(mem_start, mem_end, 4, 4)) = token; } while(0)

static unsigned long __init dt_find_string(char *str)
{
	char *s, *os;

	s = os = (char *)RELOC(dt_string_start);
	s += 4;
	while (s <  (char *)RELOC(dt_string_end)) {
		if (strcmp(s, str) == 0)
			return s - os;
		s += strlen(s) + 1;
	}
	return 0;
}

/*
 * The Open Firmware 1275 specification states properties must be 31 bytes or
 * less, however not all firmwares obey this. Make it 64 bytes to be safe.
 */
#define MAX_PROPERTY_NAME 64

static void __init scan_dt_build_strings(phandle node,
					 unsigned long *mem_start,
					 unsigned long *mem_end)
{
	char *prev_name, *namep, *sstart;
	unsigned long soff;
	phandle child;

	sstart =  (char *)RELOC(dt_string_start);

	/* get and store all property names */
	prev_name = RELOC("");
	for (;;) {
		/* 64 is max len of name including nul. */
		namep = make_room(mem_start, mem_end, MAX_PROPERTY_NAME, 1);
		if (call_prom("nextprop", 3, 1, node, prev_name, namep) != 1) {
			/* No more nodes: unwind alloc */
			*mem_start = (unsigned long)namep;
			break;
		}

 		/* skip "name" */
 		if (strcmp(namep, RELOC("name")) == 0) {
 			*mem_start = (unsigned long)namep;
 			prev_name = RELOC("name");
 			continue;
 		}
		/* get/create string entry */
		soff = dt_find_string(namep);
		if (soff != 0) {
			*mem_start = (unsigned long)namep;
			namep = sstart + soff;
		} else {
			/* Trim off some if we can */
			*mem_start = (unsigned long)namep + strlen(namep) + 1;
			RELOC(dt_string_end) = *mem_start;
		}
		prev_name = namep;
	}

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

static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
					unsigned long *mem_end)
{
	phandle child;
	char *namep, *prev_name, *sstart, *p, *ep, *lp, *path;
	unsigned long soff;
	unsigned char *valp;
	static char pname[MAX_PROPERTY_NAME];
	int l, room;

	dt_push_token(OF_DT_BEGIN_NODE, mem_start, mem_end);

	/* get the node's full name */
	namep = (char *)*mem_start;
	room = *mem_end - *mem_start;
	if (room > 255)
		room = 255;
	l = call_prom("package-to-path", 3, 1, node, namep, room);
	if (l >= 0) {
		/* Didn't fit?  Get more room. */
		if (l >= room) {
			if (l >= *mem_end - *mem_start)
				namep = make_room(mem_start, mem_end, l+1, 1);
			call_prom("package-to-path", 3, 1, node, namep, l);
		}
		namep[l] = '\0';

		/* Fixup an Apple bug where they have bogus \0 chars in the
		 * middle of the path in some properties, and extract
		 * the unit name (everything after the last '/').
		 */
		for (lp = p = namep, ep = namep + l; p < ep; p++) {
			if (*p == '/')
				lp = namep;
			else if (*p != 0)
				*lp++ = *p;
		}
		*lp = 0;
		*mem_start = _ALIGN((unsigned long)lp + 1, 4);
	}

	/* get it again for debugging */
	path = RELOC(prom_scratch);
	memset(path, 0, PROM_SCRATCH_SIZE);
	call_prom("package-to-path", 3, 1, node, path, PROM_SCRATCH_SIZE-1);

	/* get and store all properties */
	prev_name = RELOC("");
	sstart = (char *)RELOC(dt_string_start);
	for (;;) {
		if (call_prom("nextprop", 3, 1, node, prev_name,
			      RELOC(pname)) != 1)
			break;

 		/* 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);