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

        if ((long)call_prom(RELOC("getprop"), 4, 1, _prom->chosen,
			    RELOC("stdout"), &getprop_rval,
			    sizeof(getprop_rval)) <= 0)
                prom_exit();

        _prom->stdout = (ihandle)(unsigned long)getprop_rval;

#ifdef DEBUG_YABOOT
        if (_prom->stdout == 0) {
	    call_yaboot(yaboot->printf, RELOC("prom->stdout = 0x%08x%08x\n"), LONG_MSW(_prom->stdout), LONG_LSW(_prom->stdout));
        }

	call_yaboot(yaboot->printf, RELOC("prom->stdout = 0x%08x%08x\n"), LONG_MSW(_prom->stdout), LONG_LSW(_prom->stdout));
#endif

#ifdef DEBUG_YABOOT
	call_yaboot(yaboot->printf, RELOC("Location: 0x11\n"));
#endif

	mem = RELOC(klimit) - offset; 
#ifdef DEBUG_YABOOT
	call_yaboot(yaboot->printf, RELOC("Location: 0x11b\n"));
#endif

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

	getprop_rval = 1;
	prom_root = (ihandle)call_prom(RELOC("finddevice"), 1, 1, RELOC("/"));
	if (prom_root != (ihandle)-1) {
                call_prom(RELOC("getprop"), 4, 1,
                    prom_root, RELOC("#size-cells"),
		    &getprop_rval, sizeof(getprop_rval));
	}
	_prom->encode_phys_size = (getprop_rval==1) ? 32 : 64;

	/* Fetch the cmd_line */
	sz = (long)call_prom(RELOC("getprop"), 4, 1, _prom->chosen,
			    RELOC("bootargs"), _cmd_line,
			    sizeof(cmd_line)-1);
	if (sz > 0)
		_cmd_line[sz] = '\0';

	prom_parse_cmd_line(_cmd_line);

#ifdef DEBUG_PROM
	prom_print(RELOC("DRENG:    Detect OF version...\n"));
#endif
	/* Find the OF version */
	prom_op = (ihandle)call_prom(RELOC("finddevice"), 1, 1, RELOC("/openprom"));
	if (prom_op != (ihandle)-1) {
		char model[64];
		sz = (long)call_prom(RELOC("getprop"), 4, 1, prom_op,
				    RELOC("model"), model, 64);
		if (sz > 0) {
			char *c;
			/* hack to skip the ibm chrp firmware # */
			if ( strncmp(model,RELOC("IBM"),3) ) {
				for (c = model; *c; c++)
					if (*c >= '0' && *c <= '9') {
						_prom->version = *c - '0';
						break;
					}
			}
			else
				chrp = 1;
		}
	}
	if (_prom->version >= 3)
		prom_print(RELOC("OF Version 3 detected.\n"));


	/* Determine which cpu is actually running right _now_ */
        if ((long)call_prom(RELOC("getprop"), 4, 1, _prom->chosen,
			    RELOC("cpu"), &getprop_rval,
			    sizeof(getprop_rval)) <= 0)
                prom_exit();

	prom_cpu = (ihandle)(unsigned long)getprop_rval;
	cpu_pkg = call_prom(RELOC("instance-to-package"), 1, 1, prom_cpu);
	call_prom(RELOC("getprop"), 4, 1,
		cpu_pkg, RELOC("reg"),
		&getprop_rval, sizeof(getprop_rval));
	_prom->cpu = (int)(unsigned long)getprop_rval;
	_xPaca[0].xHwProcNum = _prom->cpu;

#ifdef DEBUG_PROM
  	prom_print(RELOC("Booting CPU hw index = 0x"));
  	prom_print_hex(_prom->cpu);
  	prom_print_nl();
#endif

	/* Get the boot device and translate it to a full OF pathname. */
	p = (char *) mem;
	l = (long) call_prom(RELOC("getprop"), 4, 1, _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 = DOUBLEWORD_ALIGN(mem + strlen(d) + 1);
	}

	mem = prom_initialize_lmb(mem);

	mem = prom_bi_rec_reserve(mem);

	prom_instantiate_rtas();
        
        /* Initialize some system info into the Naca early... */
        mem = prom_initialize_naca(mem);

        /* If we are on an SMP machine, then we *MUST* do the
         * following, regardless of whether we have an SMP
         * kernel or not.
         */
        if ( _naca->processorCount > 1 )
	        prom_hold_cpus(mem);

	mem = check_display(mem);

#ifdef DEBUG_PROM
	prom_print(RELOC("copying OF device tree...\n"));
#endif
	mem = copy_device_tree(mem);

	RELOC(klimit) = mem + offset;

	lmb_reserve(0, __pa(RELOC(klimit)));

	if (_naca->platform == PLATFORM_PSERIES)
		prom_initialize_tce_table();

 	if ((long) call_prom(RELOC("getprop"), 4, 1,
				_prom->chosen,
				RELOC("mmu"),
				&getprop_rval,
				sizeof(getprop_rval)) <= 0) {	
		prom_print(RELOC(" no MMU found\n"));
                prom_exit();
	}

	/* We assume the phys. address size is 3 cells */
	RELOC(prom_mmu) = (ihandle)(unsigned long)getprop_rval;

	if ((long)call_prom(RELOC("call-method"), 4, 4,
				RELOC("translate"),
				prom_mmu,
				(void *)(KERNELBASE - offset),
				(void *)1) != 0) {
		prom_print(RELOC(" (translate failed) "));
	} else {
		prom_print(RELOC(" (translate ok) "));
		phys = (unsigned long)_prom->args.rets[3];
	}

	/* If OpenFirmware version >= 3, then use quiesce call */
	if (_prom->version >= 3) {
		prom_print(RELOC("Calling quiesce ...\n"));
		call_prom(RELOC("quiesce"), 0, 0);
		phys = KERNELBASE - offset;
	}

	prom_print(RELOC("returning from prom_init\n"));
	return phys;
}


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

	return (int)(long)call_prom(RELOC("call-method"), 6, 1,
		                    RELOC("color!"),
                                    ih,
                                    (void *)(long) i,
                                    (void *)(long) b,
                                    (void *)(long) g,
                                    (void *)(long) 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 unsigned long __init
check_display(unsigned long mem)
{
	phandle node;
	ihandle ih;
	int i;
	unsigned long offset = reloc_offset();
        struct prom_t *_prom = PTRRELOC(&prom);
	char type[64], *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(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 ((long) call_prom(RELOC("package-to-path"), 3, 1,
				    node, path, 255) < 0)
			continue;
		prom_print(RELOC("opening display "));
		prom_print(path);
		ih = (ihandle)call_prom(RELOC("open"), 1, 1, path);
		if (ih == (ihandle)0 || ih == (ihandle)-1) {
			prom_print(RELOC("... failed\n"));
			continue;
		}
		prom_print(RELOC("... ok\n"));

		if (_prom->disp_node == 0)
			_prom->disp_node = (ihandle)(unsigned long)node;

		/* Setup a useable color table when the appropriate
		 * method is available. Should update this to 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 */

		/*
		 * 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_paths[i]) = PTRUNRELOC(path);
		if (RELOC(prom_num_displays) >= FB_MAX)
			break;
	}
	return DOUBLEWORD_ALIGN(mem);
}

void
virt_irq_init(void)
{
	int i;
	for (i = 0; i < NR_IRQS; i++)
		virt_irq_to_real_map[i] = UNDEFINED_IRQ;
	for (i = 0; i < NR_HW_IRQS; i++)
		real_irq_to_virt_map[i] = UNDEFINED_IRQ;
}

/* Create a mapping for a real_irq if it doesn't already exist.
 * Return the virtual irq as a convenience.
 */
unsigned long
virt_irq_create_mapping(unsigned long real_irq)
{
	unsigned long virq;
	if (naca->interrupt_controller == IC_OPEN_PIC)
		return real_irq;	/* no mapping for openpic (for now) */
	virq = real_irq_to_virt(real_irq);
	if (virq == UNDEFINED_IRQ) {
		/* Assign a virtual IRQ number */
		if (real_irq < NR_IRQS && virt_irq_to_real(real_irq) == UNDEFINED_IRQ) {
			/* A 1-1 mapping will work. */
			virq = real_irq;
		} else {
			while (last_virt_irq < NR_IRQS &&
			       virt_irq_to_real(++last_virt_irq) != UNDEFINED_IRQ)
				/* skip irq's in use */;
			if (last_virt_irq >= NR_IRQS)
				panic("Too many IRQs are required on this system.  NR_IRQS=%d\n", NR_IRQS);
			virq = last_virt_irq;
		}
		virt_irq_to_real_map[virq] = real_irq;
		real_irq_to_virt_map[real_irq] = virq;
	}
	return virq;
}


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)
{
	phandle root;
	unsigned long new_start;
	struct device_node **allnextp;
	unsigned long offset = reloc_offset();
	unsigned long mem_end = mem_start + (8<<20);

	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 = DOUBLEWORD_ALIGN(mem_start);
	new_start = inspect_node(root, 0, mem_start, mem_end, &allnextp);
	*allnextp = 0;
	return new_start;
}

__init
static unsigned long
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 ((long) call_prom(RELOC("nextprop"), 3, 1, node, prev_name,
				    namep) <= 0)
			break;
		mem_start = DOUBLEWORD_ALIGN((unsigned long)namep + strlen(namep) + 1);
		prev_name = namep;
		valp = (unsigned char *) mem_start;
		pp->value = PTRUNRELOC(valp);
		pp->length = (int)(long)
			call_prom(RELOC("getprop"), 4, 1, node, namep,
				  valp, mem_end - mem_start);
		if (pp->length < 0)
			continue;
		mem_start = DOUBLEWORD_ALIGN(mem_start + pp->length);
		*prev_propp = PTRUNRELOC(pp);
		prev_propp = &pp->next;
	}
	*prev_propp = 0;

	/* get the node's full name */
	l = (long) 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 = DOUBLEWORD_ALIGN(mem_start + l + 1);
	}

	/* do all our children */
	child = call_prom(RELOC("child"), 1, 1, node);
	while (child != (phandle)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 = klimit;

	virt_irq_init();

	mem = finish_node(allnodes, mem, NULL, 0, 0);
	dev_tree_size = mem - (unsigned long) allnodes;

	mem = _ALIGN(mem, PAGE_SIZE);
	lmb_reserve(__pa(klimit), mem-klimit);

	klimit = mem;

	rtas.dev = find_devices("rtas");
}

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);