prom.c

ARM 嵌入式 系统 设计与实例开发 实验教材 二源码

/*
 * 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(int r3, int r4, prom_entry pp)
{
	unsigned long mem;
	ihandle prom_mmu;
	unsigned long offset = reloc_offset();
	int l;
	char *p, *d;
 	unsigned long phys;

 	/* Default */
 	phys = offset + KERNELBASE;

	/* First get a handle for the stdout device */
	RELOC(prom) = pp;
	RELOC(prom_chosen) = call_prom(RELOC("finddevice"), 1, 1,
				       RELOC("/chosen"));
	if (RELOC(prom_chosen) == (void *)-1)
		prom_exit();
	if ((int) call_prom(RELOC("getprop"), 4, 1, RELOC(prom_chosen),
			    RELOC("stdout"), &RELOC(prom_stdout),
			    sizeof(prom_stdout)) <= 0)
		prom_exit();

	/* Get the full OF pathname of the stdout device */
	mem = (unsigned long) RELOC(klimit) + offset;
	p = (char *) mem;
	memset(p, 0, 256);
	call_prom(RELOC("instance-to-path"), 3, 1, RELOC(prom_stdout), p, 255);
	RELOC(of_stdout_device) = PTRUNRELOC(p);
	mem += strlen(p) + 1;

	/* Get the boot device and translate it to a full OF pathname. */
	p = (char *) mem;
	l = (int) call_prom(RELOC("getprop"), 4, 1, RELOC(prom_chosen),
			    RELOC("bootpath"), p, 1<<20);
	if (l > 0) {
		p[l] = 0;	/* should already be null-terminated */
		RELOC(bootpath) = PTRUNRELOC(p);
		mem += l + 1;
		d = (char *) mem;
		*d = 0;
		call_prom(RELOC("canon"), 3, 1, p, d, 1<<20);
		RELOC(bootdevice) = PTRUNRELOC(d);
		mem = ALIGN(mem + strlen(d) + 1);
	}

	prom_instantiate_rtas();

#ifdef CONFIG_PPC64BRIDGE
	/*
	 * Find out how much memory we have and allocate a
	 * suitably-sized hash table.
	 */
	prom_alloc_htab();
#endif

	mem = check_display(mem);

	prom_print(RELOC("copying OF device tree..."));
	mem = copy_device_tree(mem, mem + (1<<20));
	prom_print(RELOC("done\n"));

#ifdef CONFIG_SMP
	prom_hold_cpus(mem);
#endif

	RELOC(klimit) = (char *) (mem - offset);

	/* If we are already running at 0xc0000000, we assume we were loaded by
	 * an OF bootloader which did set a BAT for us. This breaks OF translate
	 * so we force phys to be 0
	 */
	if (offset == 0)
		phys = 0;
	else {
 	    if ((int) call_prom(RELOC("getprop"), 4, 1, RELOC(prom_chosen),
			    RELOC("mmu"), &prom_mmu, sizeof(prom_mmu)) <= 0) {
		prom_print(RELOC(" no MMU found\n"));
	    } else {
		int nargs;
		struct prom_args prom_args;
		nargs = 4;
		prom_args.service = RELOC("call-method");
		prom_args.nargs = nargs;
		prom_args.nret = 4;
		prom_args.args[0] = RELOC("translate");
		prom_args.args[1] = prom_mmu;
		prom_args.args[2] = (void *)(offset + KERNELBASE);
		prom_args.args[3] = (void *)1;
		RELOC(prom)(&prom_args);

		/* We assume the phys. address size is 3 cells */
		if (prom_args.args[nargs] != 0)
			prom_print(RELOC(" (translate failed)\n"));
		else
			phys = (unsigned long)prom_args.args[nargs+3];
	    }
	}

#ifdef CONFIG_BOOTX_TEXT
	if (RELOC(prom_disp_node) != 0)
		setup_disp_fake_bi(RELOC(prom_disp_node));
#endif

	/* Use quiesce call to get OF to shut down any devices it's using */
	prom_print(RELOC("Calling quiesce ...\n"));
	call_prom(RELOC("quiesce"), 0, 0);

#ifdef CONFIG_BOOTX_TEXT
	if (RELOC(prom_disp_node) != 0)
		btext_prepare_BAT();
#endif

	prom_print(RELOC("returning "));
	prom_print_hex(phys);
	prom_print(RELOC(" from prom_init\n"));
	RELOC(prom_stdout) = 0;

	return phys;
}

void phys_call_rtas(int service, int nargs, int nret, ...)
{
	va_list list;
	union {
		unsigned long words[16];
		double align;
	} u;
	unsigned long offset = reloc_offset();
	void (*rtas)(void *, unsigned long);
	int i;

	u.words[0] = service;
	u.words[1] = nargs;
	u.words[2] = nret;
	va_start(list, nret);
	for (i = 0; i < nargs; ++i)
		u.words[i+3] = va_arg(list, unsigned long);
	va_end(list);

	rtas = (void (*)(void *, unsigned long)) RELOC(rtas_entry);
	rtas(&u, RELOC(rtas_data));
}

static int __init
prom_set_color(ihandle ih, int i, int r, int g, int b)
{
	struct prom_args prom_args;
	unsigned long offset = reloc_offset();

	prom_args.service = RELOC("call-method");
	prom_args.nargs = 6;
	prom_args.nret = 1;
	prom_args.args[0] = RELOC("color!");
	prom_args.args[1] = ih;
	prom_args.args[2] = (void *) i;
	prom_args.args[3] = (void *) b;
	prom_args.args[4] = (void *) g;
	prom_args.args[5] = (void *) r;
	RELOC(prom)(&prom_args);
	return (int) prom_args.args[6];
}

/*
 * 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 unsigned long __init
check_display(unsigned long mem)
{
	phandle node;
	ihandle ih;
	int i;
	unsigned long offset = reloc_offset();
	char type[16], *path;
	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
	};

	RELOC(prom_disp_node) = 0;

	for (node = 0; prom_next_node(&node); ) {
		type[0] = 0;
		call_prom(RELOC("getprop"), 4, 1, node, RELOC("device_type"),
			  type, sizeof(type));
		if (strcmp(type, RELOC("display")) != 0)
			continue;
		/* It seems OF doesn't null-terminate the path :-( */
		path = (char *) mem;
		memset(path, 0, 256);
		if ((int) call_prom(RELOC("package-to-path"), 3, 1,
				    node, path, 255) < 0)
			continue;

		/*
		 * If this display is the device that OF is using for stdout,
		 * move it to the front of the list.
		 */
		mem += strlen(path) + 1;
		i = RELOC(prom_num_displays)++;
		if (RELOC(of_stdout_device) != 0 && i > 0
		    && strcmp(PTRRELOC(RELOC(of_stdout_device)), path) == 0) {
			for (; i > 0; --i) {
				RELOC(prom_display_paths[i])
					= RELOC(prom_display_paths[i-1]);
				RELOC(prom_display_nodes[i])
					= RELOC(prom_display_nodes[i-1]);
			}
		}
		RELOC(prom_display_paths[i]) = PTRUNRELOC(path);
		RELOC(prom_display_nodes[i]) = node;
		if (i == 0)
			RELOC(prom_disp_node) = node;
		if (RELOC(prom_num_displays) >= FB_MAX)
			break;
	}

try_again:
	/*
	 * Open the first display and set its colormap.
	 */
	if (RELOC(prom_num_displays) > 0) {
		path = PTRRELOC(RELOC(prom_display_paths[0]));
		prom_print(RELOC("opening display "));
		prom_print(path);
		ih = call_prom(RELOC("open"), 1, 1, path);
		if (ih == 0 || ih == (ihandle) -1) {
			prom_print(RELOC("... failed\n"));
			for (i=1; i<RELOC(prom_num_displays); i++) {
				RELOC(prom_display_paths[i-1]) = RELOC(prom_display_paths[i]);
				RELOC(prom_display_nodes[i-1]) = RELOC(prom_display_nodes[i]);
			}
			if (--RELOC(prom_num_displays) > 0)
				RELOC(prom_disp_node) = RELOC(prom_display_nodes[0]);
			else
				RELOC(prom_disp_node) = NULL;
			goto try_again;
		} else {
			prom_print(RELOC("... ok\n"));
			/*
			 * Setup a usable color table when the appropriate
			 * method is available.
			 * Should update this to use set-colors.
			 */
			for (i = 0; i < 32; i++)
				if (prom_set_color(ih, i, RELOC(default_colors)[i*3],
						   RELOC(default_colors)[i*3+1],
						   RELOC(default_colors)[i*3+2]) != 0)
					break;

#ifdef CONFIG_FB
			for (i = 0; i < LINUX_LOGO_COLORS; i++)
				if (prom_set_color(ih, i + 32,
						   RELOC(linux_logo_red)[i],
						   RELOC(linux_logo_green)[i],
						   RELOC(linux_logo_blue)[i]) != 0)
					break;
#endif /* CONFIG_FB */
		}
	}

	return ALIGN(mem);
}

/* This function will enable the early boot text when doing OF booting. This
 * way, xmon output should work too
 */
#ifdef CONFIG_BOOTX_TEXT
static void __init
setup_disp_fake_bi(ihandle dp)
{
	int width = 640, height = 480, depth = 8, pitch;
	unsigned address;
	unsigned long offset = reloc_offset();
	struct pci_reg_property addrs[8];
	int i, naddrs;
	char name[32];
	char *getprop = RELOC("getprop");

	prom_print(RELOC("Initializing fake screen: "));

	memset(name, 0, sizeof(name));
	call_prom(getprop, 4, 1, dp, RELOC("name"), name, sizeof(name));
	name[sizeof(name)-1] = 0;
	prom_print(name);
	prom_print(RELOC("\n"));
	call_prom(getprop, 4, 1, dp, RELOC("width"), &width, sizeof(width));
	call_prom(getprop, 4, 1, dp, RELOC("height"), &height, sizeof(height));
	call_prom(getprop, 4, 1, dp, RELOC("depth"), &depth, sizeof(depth));
	pitch = width * ((depth + 7) / 8);
	call_prom(getprop, 4, 1, dp, RELOC("linebytes"),
		  &pitch, sizeof(pitch));
	if (pitch == 1)
		pitch = 0x1000;		/* for strange IBM display */
	address = 0;
	call_prom(getprop, 4, 1, dp, RELOC("address"),
		  &address, sizeof(address));
	if (address == 0) {
		/* look for an assigned address with a size of >= 1MB */
		naddrs = (int) call_prom(getprop, 4, 1, dp,
				RELOC("assigned-addresses"),
				addrs, sizeof(addrs));
		naddrs /= sizeof(struct pci_reg_property);
		for (i = 0; i < naddrs; ++i) {
			if (addrs[i].size_lo >= (1 << 20)) {
				address = addrs[i].addr.a_lo;
				/* use the BE aperture if possible */
				if (addrs[i].size_lo >= (16 << 20))
					address += (8 << 20);
				break;
			}
		}
		if (address == 0) {
			prom_print(RELOC("Failed to get address\n"));
			return;
		}
	}
	/* kludge for valkyrie */
	if (strcmp(name, RELOC("valkyrie")) == 0)
		address += 0x1000;

	btext_setup_display(width, height, depth, pitch, address);
}
#endif

static int __init
prom_next_node(phandle *nodep)
{
	phandle node;
	unsigned long offset = reloc_offset();

	if ((node = *nodep) != 0
	    && (*nodep = call_prom(RELOC("child"), 1, 1, node)) != 0)
		return 1;
	if ((*nodep = call_prom(RELOC("peer"), 1, 1, node)) != 0)
		return 1;
	for (;;) {
		if ((node = call_prom(RELOC("parent"), 1, 1, node)) == 0)
			return 0;
		if ((*nodep = call_prom(RELOC("peer"), 1, 1, node)) != 0)
			return 1;
	}
}

/*
 * Make a copy of the device tree from the PROM.
 */
static unsigned long __init
copy_device_tree(unsigned long mem_start, unsigned long mem_end)
{
	phandle root;
	unsigned long new_start;
	struct device_node **allnextp;
	unsigned long offset = reloc_offset();

	root = call_prom(RELOC("peer"), 1, 1, (phandle)0);
	if (root == (phandle)0) {
		prom_print(RELOC("couldn't get device tree root\n"));
		prom_exit();
	}
	allnextp = &RELOC(allnodes);
	mem_start = ALIGN(mem_start);
	new_start = inspect_node(root, 0, mem_start, mem_end, &allnextp);
	*allnextp = 0;
	return new_start;
}

static unsigned long __init
inspect_node(phandle node, struct device_node *dad,
	     unsigned long mem_start, unsigned long mem_end,
	     struct device_node ***allnextpp)
{
	int l;
	phandle child;
	struct device_node *np;
	struct property *pp, **prev_propp;
	char *prev_name, *namep;
	unsigned char *valp;
	unsigned long offset = reloc_offset();

	np = (struct device_node *) mem_start;
	mem_start += sizeof(struct device_node);
	memset(np, 0, sizeof(*np));
	np->node = node;
	**allnextpp = PTRUNRELOC(np);
	*allnextpp = &np->allnext;
	if (dad != 0) {
		np->parent = PTRUNRELOC(dad);
		/* we temporarily use the `next' field as `last_child'. */
		if (dad->next == 0)
			dad->child = PTRUNRELOC(np);
		else
			dad->next->sibling = PTRUNRELOC(np);
		dad->next = np;
	}

	/* get and store all properties */
	prev_propp = &np->properties;
	prev_name = RELOC("");
	for (;;) {
		pp = (struct property *) mem_start;
		namep = (char *) (pp + 1);
		pp->name = PTRUNRELOC(namep);
		if ((int) call_prom(RELOC("nextprop"), 3, 1, node, prev_name,
				    namep) <= 0)
			break;
		mem_start = ALIGN((unsigned long)namep + strlen(namep) + 1);
		prev_name = namep;
		valp = (unsigned char *) mem_start;
		pp->value = PTRUNRELOC(valp);
		pp->length = (int)
			call_prom(RELOC("getprop"), 4, 1, node, namep,
				  valp, mem_end - mem_start);
		if (pp->length < 0)
			continue;
#ifdef MAX_PROPERTY_LENGTH
		if (pp->length > MAX_PROPERTY_LENGTH)
			continue; /* ignore this property */
#endif
		mem_start = ALIGN(mem_start + pp->length);
		*prev_propp = PTRUNRELOC(pp);
		prev_propp = &pp->next;
	}
	if (np->node != NULL) {
		/* Add a "linux,phandle" property" */
		pp = (struct property *) mem_start;
		*prev_propp = PTRUNRELOC(pp);
		prev_propp = &pp->next;
		namep = (char *) (pp + 1);
		pp->name = PTRUNRELOC(namep);
		strcpy(namep, RELOC("linux,phandle"));
		mem_start = ALIGN((unsigned long)namep + strlen(namep) + 1);
		pp->value = (unsigned char *) PTRUNRELOC(&np->node);
		pp->length = sizeof(np->node);
	}
	*prev_propp = NULL;

	/* get the node's full name */
	l = (int) call_prom(RELOC("package-to-path"), 3, 1, node,
			    (char *) mem_start, mem_end - mem_start);
	if (l >= 0) {
		np->full_name = PTRUNRELOC((char *) mem_start);
		*(char *)(mem_start + l) = 0;
		mem_start = ALIGN(mem_start + l + 1);
	}

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

	return mem_start;
}

/*
 * finish_device_tree is called once things are running normally
 * (i.e. with text and data mapped to the address they were linked at).
 * It traverses the device tree and fills in the name, type,
 * {n_}addrs and {n_}intrs fields of each node.
 */
void __init
finish_device_tree(void)
{
	unsigned long mem = (unsigned long) klimit;
	struct device_node *np;

	/* All newworld pmac machines and CHRPs now use the interrupt tree */
	for (np = allnodes; np != NULL; np = np->allnext) {
		if (get_property(np, "interrupt-parent", 0)) {
			use_of_interrupt_tree = 1;
			break;
		}
	}
	if (_machine == _MACH_Pmac && use_of_interrupt_tree)
		pmac_newworld = 1;

#ifdef CONFIG_BOOTX_TEXT
	if (boot_infos && pmac_newworld) {
		prom_print("WARNING ! BootX/miBoot booting is not supported on this machine\n");
		prom_print("          You should use an Open Firmware bootloader\n");
	}
#endif /* CONFIG_BOOTX_TEXT */

	if (use_of_interrupt_tree) {
		/*
		 * We want to find out here how many interrupt-controller
		 * nodes there are, and if we are booted from BootX,
		 * we need a pointer to the first (and hopefully only)
		 * such node.  But we can't use find_devices here since
		 * np->name has not been set yet.  -- paulus
		 */
		int n = 0;
		char *name, *ic;
		int iclen;

		for (np = allnodes; np != NULL; np = np->allnext) {
			ic = get_property(np, "interrupt-controller", &iclen);
			name = get_property(np, "name", NULL);
			/* checking iclen makes sure we don't get a false
			   match on /chosen.interrupt_controller */
			if ((name != NULL
			     && strcmp(name, "interrupt-controller") == 0)
			    || (ic != NULL && iclen == 0)) {
				if (n == 0)
					dflt_interrupt_controller = np;
				++n;
			}
		}
		num_interrupt_controllers = n;
	}

	mem = finish_node(allnodes, mem, NULL, 1, 1);
	dev_tree_size = mem - (unsigned long) allnodes;
	klimit = (char *) mem;
}