prom_init.c

是关于linux2.5.1的完全源码

/*
 * Note that prom_init() and anything called from prom_init()
 * may be running at an address that is different from the address
 * that it was linked at.  References to static data items are
 * handled by compiling this file with -mrelocatable-lib.
 */

#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/ioport.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/io.h>
#include <asm/smp.h>
#include <asm/bootx.h>
#include <asm/system.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/bitops.h>
#include <asm/bootinfo.h>
#include <asm/btext.h>
#include <asm/pci-bridge.h>
#include <asm/open_pic.h>
#include <asm/cacheflush.h>

#ifdef CONFIG_FB
#include <asm/linux_logo.h>
#endif

/*
 * Properties whose value is longer than this get excluded from our
 * copy of the device tree.  This way we don't waste space storing
 * things like "driver,AAPL,MacOS,PowerPC" properties.  But this value
 * does need to be big enough to ensure that we don't lose things
 * like the interrupt-map property on a PCI-PCI bridge.
 */
#define MAX_PROPERTY_LENGTH	4096

#ifndef FB_MAX			/* avoid pulling in all of the fb stuff */
#define FB_MAX	8
#endif

#define ALIGNUL(x) (((x) + sizeof(unsigned long)-1) & -sizeof(unsigned long))

struct prom_args {
	const char *service;
	int nargs;
	int nret;
	void *args[10];
};

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 pci_range {
	struct pci_address addr;
	unsigned phys;
	unsigned size_hi;
	unsigned size_lo;
};

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

struct pci_intr_map {
	struct pci_address addr;
	unsigned dunno;
	phandle int_ctrler;
	unsigned intr;
};

static void prom_exit(void);
static void *call_prom(const char *service, int nargs, int nret, ...);
static void *call_prom_ret(const char *service, int nargs, int nret,
			   void **rets, ...);
static void prom_print_hex(unsigned int v);
static int  prom_set_color(ihandle ih, int i, int r, int g, int b);
static int  prom_next_node(phandle *nodep);
static unsigned long check_display(unsigned long mem);
static void setup_disp_fake_bi(ihandle dp);
static unsigned long copy_device_tree(unsigned long mem_start,
				unsigned long mem_end);
static unsigned long inspect_node(phandle node, struct device_node *dad,
				unsigned long mem_start, unsigned long mem_end,
				struct device_node ***allnextpp);
static void prom_hold_cpus(unsigned long mem);
static void prom_instantiate_rtas(void);
static void * early_get_property(unsigned long base, unsigned long node,
				char *prop);

prom_entry prom __initdata = 0;
ihandle prom_chosen __initdata = 0;
ihandle prom_stdout __initdata = 0;

char *prom_display_paths[FB_MAX] __initdata = { 0, };
phandle prom_display_nodes[FB_MAX] __initdata;
unsigned int prom_num_displays __initdata = 0;
static char *of_stdout_device __initdata = 0;
static ihandle prom_disp_node __initdata = 0;

unsigned int rtas_data;   /* physical pointer */
unsigned int rtas_entry;  /* physical pointer */
unsigned int rtas_size;
unsigned int old_rtas;

boot_infos_t *boot_infos;
char *bootpath;
char *bootdevice;
struct device_node *allnodes;

extern char *klimit;
extern char _stext;

static void __init
prom_exit(void)
{
	struct prom_args args;

	args.service = "exit";
	args.nargs = 0;
	args.nret = 0;
	prom(&args);
	for (;;)			/* should never get here */
		;
}

static void * __init
call_prom(const char *service, int nargs, int nret, ...)
{
	va_list list;
	int i;
	struct prom_args prom_args;

	prom_args.service = service;
	prom_args.nargs = nargs;
	prom_args.nret = nret;
	va_start(list, nret);
	for (i = 0; i < nargs; ++i)
		prom_args.args[i] = va_arg(list, void *);
	va_end(list);
	for (i = 0; i < nret; ++i)
		prom_args.args[i + nargs] = 0;
	prom(&prom_args);
	return prom_args.args[nargs];
}

static void * __init
call_prom_ret(const char *service, int nargs, int nret, void **rets, ...)
{
	va_list list;
	int i;
	struct prom_args prom_args;

	prom_args.service = service;
	prom_args.nargs = nargs;
	prom_args.nret = nret;
	va_start(list, rets);
	for (i = 0; i < nargs; ++i)
		prom_args.args[i] = va_arg(list, void *);
	va_end(list);
	for (i = 0; i < nret; ++i)
		prom_args.args[i + nargs] = 0;
	prom(&prom_args);
	for (i = 1; i < nret; ++i)
		rets[i-1] = prom_args.args[nargs + i];
	return prom_args.args[nargs];
}

void __init
prom_print(const char *msg)
{
	const char *p, *q;

	if (prom_stdout == 0)
		return;

	for (p = msg; *p != 0; p = q) {
		for (q = p; *q != 0 && *q != '\n'; ++q)
			;
		if (q > p)
			call_prom("write", 3, 1, prom_stdout, p, q - p);
		if (*q != 0) {
			++q;
			call_prom("write", 3, 1, prom_stdout, "\r\n", 2);
		}
	}
}

static void __init
prom_print_hex(unsigned int v)
{
	char buf[16];
	int i, c;

	for (i = 0; i < 8; ++i) {
		c = (v >> ((7-i)*4)) & 0xf;
		c += (c >= 10)? ('a' - 10): '0';
		buf[i] = c;
	}
	buf[i] = ' ';
	buf[i+1] = 0;
	prom_print(buf);
}

static int __init
prom_set_color(ihandle ih, int i, int r, int g, int b)
{
	struct prom_args prom_args;

	prom_args.service = "call-method";
	prom_args.nargs = 6;
	prom_args.nret = 1;
	prom_args.args[0] = "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;
	prom(&prom_args);
	return (int) prom_args.args[6];
}

static int __init
prom_next_node(phandle *nodep)
{
	phandle node;

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

/*
 * 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;
	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
	};

	prom_disp_node = 0;

	for (node = 0; prom_next_node(&node); ) {
		type[0] = 0;
		call_prom("getprop", 4, 1, node, "device_type",
			  type, sizeof(type));
		if (strcmp(type, "display") != 0)
			continue;
		/* It seems OF doesn't null-terminate the path :-( */
		path = (char *) mem;
		memset(path, 0, 256);
		if ((int) call_prom("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 = prom_num_displays++;
		if (of_stdout_device != 0 && i > 0
		    && strcmp(of_stdout_device, path) == 0) {
			for (; i > 0; --i) {
				prom_display_paths[i]
					= prom_display_paths[i-1];
				prom_display_nodes[i]
					= prom_display_nodes[i-1];
			}
		}
		prom_display_paths[i] = path;
		prom_display_nodes[i] = node;
		if (i == 0)
			prom_disp_node = node;
		if (prom_num_displays >= FB_MAX)
			break;
	}

try_again:
	/*
	 * Open the first display and set its colormap.
	 */
	if (prom_num_displays > 0) {
		path = prom_display_paths[0];
		prom_print("opening display ");
		prom_print(path);
		ih = call_prom("open", 1, 1, path);
		if (ih == 0 || ih == (ihandle) -1) {
			prom_print("... failed\n");
			for (i=1; i<prom_num_displays; i++) {
				prom_display_paths[i-1] = prom_display_paths[i];
				prom_display_nodes[i-1] = prom_display_nodes[i];
			}
			if (--prom_num_displays > 0)
				prom_disp_node = prom_display_nodes[0];
			else
				prom_disp_node = NULL;
			goto try_again;
		} else {
			prom_print("... 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, default_colors[i*3],
						   default_colors[i*3+1],
						   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,
						   linux_logo_red[i],
						   linux_logo_green[i],
						   linux_logo_blue[i]) != 0)
					break;
#endif /* CONFIG_FB */
		}
	}

	return ALIGNUL(mem);
}

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

	prom_print("Initializing fake screen: ");

	memset(name, 0, sizeof(name));
	call_prom(getprop, 4, 1, dp, "name", name, sizeof(name));
	name[sizeof(name)-1] = 0;
	prom_print(name);
	prom_print("\n");
	call_prom(getprop, 4, 1, dp, "width", &width, sizeof(width));
	call_prom(getprop, 4, 1, dp, "height", &height, sizeof(height));
	call_prom(getprop, 4, 1, dp, "depth", &depth, sizeof(depth));
	pitch = width * ((depth + 7) / 8);
	call_prom(getprop, 4, 1, dp, "linebytes",
		  &pitch, sizeof(pitch));
	if (pitch == 1)
		pitch = 0x1000;		/* for strange IBM display */
	address = 0;
	call_prom(getprop, 4, 1, dp, "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,
				"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("Failed to get address\n");
			return;
		}
	}
	/* kludge for valkyrie */
	if (strcmp(name, "valkyrie") == 0)
		address += 0x1000;

	btext_setup_display(width, height, depth, pitch, address);

	btext_prepare_BAT();
#endif /* CONFIG_BOOTX_TEXT */
}

/*
 * 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;