prom.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * BK Id: %F% %I% %G% %U% %#%
 */
/*
 * Procedures for interfacing to the Open Firmware PROM on
 * Power Macintosh computers.
 *
 * In particular, we are interested in the device tree
 * and in using some of its services (exit, write to stdout).
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996 Paul Mackerras.
 */
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/version.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/slab.h>

#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/open_pic.h>
#include <asm/system.h>
#include <asm/btext.h>
#include <asm/pci-bridge.h>

struct pci_address {
	unsigned a_hi;
	unsigned a_mid;
	unsigned a_lo;
};

struct pci_reg_property {
	struct pci_address addr;
	unsigned size_hi;
	unsigned size_lo;
};

struct isa_reg_property {
	unsigned space;
	unsigned address;
	unsigned size;
};

typedef unsigned long interpret_func(struct device_node *, unsigned long,
				     int, int);
static interpret_func interpret_pci_props;
static interpret_func interpret_dbdma_props;
static interpret_func interpret_isa_props;
static interpret_func interpret_macio_props;
static interpret_func interpret_root_props;

extern char *klimit;

/* Set for a newworld or CHRP machine */
int use_of_interrupt_tree;
struct device_node *dflt_interrupt_controller;
int num_interrupt_controllers;

int pmac_newworld;

extern unsigned int rtas_entry;  /* physical pointer */

extern struct device_node *allnodes;

static unsigned long finish_node(struct device_node *, unsigned long,
				 interpret_func *, int, int);
static unsigned long finish_node_interrupts(struct device_node *, unsigned long);

extern void enter_rtas(void *);
void phys_call_rtas(int, int, int, ...);

extern char cmd_line[512];	/* XXX */
extern boot_infos_t *boot_infos;
unsigned long dev_tree_size;

void __openfirmware
phys_call_rtas(int service, int nargs, int nret, ...)
{
	va_list list;
	union {
		unsigned long words[16];
		double align;
	} u;
	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)) rtas_entry;
	rtas(&u, rtas_data);
}

/*
 * 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 && strcmp(name, "AppleKiwi"))) {
				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;
}

static unsigned long __init
finish_node(struct device_node *np, unsigned long mem_start,
	    interpret_func *ifunc, int naddrc, int nsizec)
{
	struct device_node *child;
	int *ip;

	np->name = get_property(np, "name", 0);
	np->type = get_property(np, "device_type", 0);

	if (!np->name)
		np->name = "<NULL>";
	if (!np->type)
		np->type = "<NULL>";

	/* get the device addresses and interrupts */
	if (ifunc != NULL)
		mem_start = ifunc(np, mem_start, naddrc, nsizec);

	if (use_of_interrupt_tree)
		mem_start = finish_node_interrupts(np, mem_start);

	/* Look for #address-cells and #size-cells properties. */
	ip = (int *) get_property(np, "#address-cells", 0);
	if (ip != NULL)
		naddrc = *ip;
	ip = (int *) get_property(np, "#size-cells", 0);
	if (ip != NULL)
		nsizec = *ip;

	if (np->parent == NULL)
		ifunc = interpret_root_props;
	else if (np->type == 0)
		ifunc = NULL;
	else if (!strcmp(np->type, "pci") || !strcmp(np->type, "vci"))
		ifunc = interpret_pci_props;
	else if (!strcmp(np->type, "dbdma"))
		ifunc = interpret_dbdma_props;
	else if (!strcmp(np->type, "mac-io")
		 || ifunc == interpret_macio_props)
		ifunc = interpret_macio_props;
	else if (!strcmp(np->type, "isa"))
		ifunc = interpret_isa_props;
	else if (!strcmp(np->name, "uni-n"))
		ifunc = interpret_root_props;
	else if (!((ifunc == interpret_dbdma_props
		    || ifunc == interpret_macio_props)
		   && (!strcmp(np->type, "escc")
		       || !strcmp(np->type, "media-bay"))))
		ifunc = NULL;

	/* if we were booted from BootX, convert the full name */
	if (boot_infos
	    && strncmp(np->full_name, "Devices:device-tree", 19) == 0) {
		if (np->full_name[19] == 0) {
			strcpy(np->full_name, "/");
		} else if (np->full_name[19] == ':') {
			char *p = np->full_name + 19;
			np->full_name = p;
			for (; *p; ++p)
				if (*p == ':')
					*p = '/';
		}
	}

	for (child = np->child; child != NULL; child = child->sibling)
		mem_start = finish_node(child, mem_start, ifunc,
					naddrc, nsizec);

	return mem_start;
}

/*
 * Find the interrupt parent of a node.
 */
static struct device_node * __init
intr_parent(struct device_node *p)
{
	phandle *parp;

	parp = (phandle *) get_property(p, "interrupt-parent", NULL);
	if (parp == NULL)
		return p->parent;
	p = find_phandle(*parp);
	if (p != NULL)
		return p;
	/*
	 * On a powermac booted with BootX, we don't get to know the
	 * phandles for any nodes, so find_phandle will return NULL.
	 * Fortunately these machines only have one interrupt controller
	 * so there isn't in fact any ambiguity.  -- paulus
	 */
	if (num_interrupt_controllers == 1)
		p = dflt_interrupt_controller;
	return p;
}

/*
 * Find out the size of each entry of the interrupts property
 * for a node.
 */
static int __init
prom_n_intr_cells(struct device_node *np)
{
	struct device_node *p;
	unsigned int *icp;

	for (p = np; (p = intr_parent(p)) != NULL; ) {
		icp = (unsigned int *)
			get_property(p, "#interrupt-cells", NULL);
		if (icp != NULL)
			return *icp;
		if (get_property(p, "interrupt-controller", NULL) != NULL
		    || get_property(p, "interrupt-map", NULL) != NULL) {
			printk("oops, node %s doesn't have #interrupt-cells\n",
			       p->full_name);
			return 1;
		}
	}
	printk("prom_n_intr_cells failed for %s\n", np->full_name);
	return 1;
}

/*
 * Map an interrupt from a device up to the platform interrupt
 * descriptor.
 */
static int __init
map_interrupt(unsigned int **irq, struct device_node **ictrler,
	      struct device_node *np, unsigned int *ints, int nintrc)
{
	struct device_node *p, *ipar;
	unsigned int *imap, *imask, *ip;
	int i, imaplen, match;
	int newintrc, newaddrc;
	unsigned int *reg;
	int naddrc;

	reg = (unsigned int *) get_property(np, "reg", NULL);
	naddrc = prom_n_addr_cells(np);
	p = intr_parent(np);
	while (p != NULL) {
		if (get_property(p, "interrupt-controller", NULL) != NULL)
			/* this node is an interrupt controller, stop here */
			break;
		imap = (unsigned int *)
			get_property(p, "interrupt-map", &imaplen);
		if (imap == NULL) {
			p = intr_parent(p);
			continue;
		}
		imask = (unsigned int *)
			get_property(p, "interrupt-map-mask", NULL);
		if (imask == NULL) {
			printk("oops, %s has interrupt-map but no mask\n",
			       p->full_name);
			return 0;
		}
		imaplen /= sizeof(unsigned int);
		match = 0;
		ipar = NULL;
		while (imaplen > 0 && !match) {
			/* check the child-interrupt field */
			match = 1;
			for (i = 0; i < naddrc && match; ++i)
				match = ((reg[i] ^ imap[i]) & imask[i]) == 0;
			for (; i < naddrc + nintrc && match; ++i)
				match = ((ints[i-naddrc] ^ imap[i]) & imask[i]) == 0;
			imap += naddrc + nintrc;
			imaplen -= naddrc + nintrc;
			/* grab the interrupt parent */
			ipar = find_phandle((phandle) *imap++);
			--imaplen;
			if (ipar == NULL && num_interrupt_controllers == 1)
				/* cope with BootX not giving us phandles */
				ipar = dflt_interrupt_controller;
			if (ipar == NULL) {
				printk("oops, no int parent %x in map of %s\n",
				       imap[-1], p->full_name);
				return 0;
			}
			/* find the parent's # addr and intr cells */
			ip = (unsigned int *)
				get_property(ipar, "#interrupt-cells", NULL);
			if (ip == NULL) {
				printk("oops, no #interrupt-cells on %s\n",
				       ipar->full_name);
				return 0;
			}
			newintrc = *ip;
			ip = (unsigned int *)
				get_property(ipar, "#address-cells", NULL);
			newaddrc = (ip == NULL)? 0: *ip;
			imap += newaddrc + newintrc;
			imaplen -= newaddrc + newintrc;
		}
		if (imaplen < 0) {
			printk("oops, error decoding int-map on %s, len=%d\n",
			       p->full_name, imaplen);
			return 0;
		}
		if (!match) {
			printk("oops, no match in %s int-map for %s\n",
			       p->full_name, np->full_name);
			return 0;
		}
		p = ipar;
		naddrc = newaddrc;
		nintrc = newintrc;
		ints = imap - nintrc;
		reg = ints - naddrc;
	}
	if (p == NULL)
		printk("hmmm, int tree for %s doesn't have ctrler\n",
		       np->full_name);
	*irq = ints;
	*ictrler = p;
	return nintrc;
}

/*
 * New version of finish_node_interrupts.
 */
static unsigned long __init
finish_node_interrupts(struct device_node *np, unsigned long mem_start)
{
	unsigned int *ints;
	int intlen, intrcells;
	int i, j, n, offset;
	unsigned int *irq;
	struct device_node *ic;

	ints = (unsigned int *) get_property(np, "interrupts", &intlen);
	if (ints == NULL)
		return mem_start;
	intrcells = prom_n_intr_cells(np);
	intlen /= intrcells * sizeof(unsigned int);
	np->n_intrs = intlen;
	np->intrs = (struct interrupt_info *) mem_start;
	mem_start += intlen * sizeof(struct interrupt_info);

	for (i = 0; i < intlen; ++i) {
		np->intrs[i].line = 0;
		np->intrs[i].sense = 1;
		n = map_interrupt(&irq, &ic, np, ints, intrcells);
		if (n <= 0)
			continue;
		offset = 0;
		/*