bootx_init.c

linux内核源码

	memcpy((void *)*mem_end, namep, l + 1);
	namep = (char *)*mem_end;
	for (lp = p = namep, ep = namep + l; p < ep; p++) {
		if (*p == '/')
			lp = namep;
		else if (*p != 0)
			*lp++ = *p;
	}
	*lp = 0;
	*mem_end = _ALIGN_UP((unsigned long)lp + 1, 4);

	/* get and store all properties */
	while (*ppp) {
		struct bootx_dt_prop *pp =
			(struct bootx_dt_prop *)(base + *ppp);

		namep = pp->name ? (char *)(base + pp->name) : NULL;
		/* Skip "name" */
 		if (namep == NULL || !strcmp(namep, "name"))
 			goto next;
		/* Skip "bootargs" in /chosen too as we replace it */
		if (node == bootx_node_chosen && !strcmp(namep, "bootargs"))
			goto next;

		/* push property head */
		bootx_dt_add_prop(namep,
				  pp->value ? (void *)(base + pp->value): NULL,
				  pp->length, mem_end);
	next:
		ppp = &pp->next;
	}

	if (node == bootx_node_chosen) {
		bootx_add_chosen_props(base, mem_end);
		if (bootx_info->dispDeviceRegEntryOffset == 0)
			bootx_add_display_props(base, mem_end, 0);
	}
	else if (node == bootx_info->dispDeviceRegEntryOffset)
		bootx_add_display_props(base, mem_end, 1);

	/* do all our children */
	cpp = &np->child;
	while(*cpp) {
		np = (struct bootx_dt_node *)(base + *cpp);
		bootx_scan_dt_build_struct(base, *cpp, mem_end);
		cpp = &np->sibling;
	}

	dt_push_token(OF_DT_END_NODE, mem_end);
}

static unsigned long __init bootx_flatten_dt(unsigned long start)
{
	boot_infos_t *bi = bootx_info;
	unsigned long mem_start, mem_end;
	struct boot_param_header *hdr;
	unsigned long base;
	u64 *rsvmap;

	/* Start using memory after the big blob passed by BootX, get
	 * some space for the header
	 */
	mem_start = mem_end = _ALIGN_UP(((unsigned long)bi) + start, 4);
	DBG("Boot params header at: %x\n", mem_start);
	hdr = (struct boot_param_header *)mem_start;
	mem_end += sizeof(struct boot_param_header);
	rsvmap = (u64 *)(_ALIGN_UP(mem_end, 8));
	hdr->off_mem_rsvmap = ((unsigned long)rsvmap) - mem_start;
	mem_end = ((unsigned long)rsvmap) + 8 * sizeof(u64);

	/* Get base of tree */
	base = ((unsigned long)bi) + bi->deviceTreeOffset;

	/* Build string array */
	DBG("Building string array at: %x\n", mem_end);
	DBG("Device Tree Base=%x\n", base);
	bootx_dt_strbase = mem_end;
	mem_end += 4;
	bootx_dt_strend = mem_end;
	bootx_scan_dt_build_strings(base, 4, &mem_end);
	/* Add some strings */
	bootx_dt_add_string("linux,bootx-noscreen", &mem_end);
	bootx_dt_add_string("linux,bootx-depth", &mem_end);
	bootx_dt_add_string("linux,bootx-width", &mem_end);
	bootx_dt_add_string("linux,bootx-height", &mem_end);
	bootx_dt_add_string("linux,bootx-linebytes", &mem_end);
	bootx_dt_add_string("linux,bootx-addr", &mem_end);
	/* Wrap up strings */
	hdr->off_dt_strings = bootx_dt_strbase - mem_start;
	hdr->dt_strings_size = bootx_dt_strend - bootx_dt_strbase;

	/* Build structure */
	mem_end = _ALIGN(mem_end, 16);
	DBG("Building device tree structure at: %x\n", mem_end);
	hdr->off_dt_struct = mem_end - mem_start;
	bootx_scan_dt_build_struct(base, 4, &mem_end);
	dt_push_token(OF_DT_END, &mem_end);

	/* Finish header */
	hdr->boot_cpuid_phys = 0;
	hdr->magic = OF_DT_HEADER;
	hdr->totalsize = mem_end - mem_start;
	hdr->version = OF_DT_VERSION;
	/* Version 16 is not backward compatible */
	hdr->last_comp_version = 0x10;

	/* Reserve the whole thing and copy the reserve map in, we
	 * also bump mem_reserve_cnt to cause further reservations to
	 * fail since it's too late.
	 */
	mem_end = _ALIGN(mem_end, PAGE_SIZE);
	DBG("End of boot params: %x\n", mem_end);
	rsvmap[0] = mem_start;
	rsvmap[1] = mem_end;
	if (bootx_info->ramDisk) {
		rsvmap[2] = ((unsigned long)bootx_info) + bootx_info->ramDisk;
		rsvmap[3] = rsvmap[2] + bootx_info->ramDiskSize;
		rsvmap[4] = 0;
		rsvmap[5] = 0;
	} else {
		rsvmap[2] = 0;
		rsvmap[3] = 0;
	}

	return (unsigned long)hdr;
}


#ifdef CONFIG_BOOTX_TEXT
static void __init btext_welcome(boot_infos_t *bi)
{
	unsigned long flags;
	unsigned long pvr;

	bootx_printf("Welcome to Linux, kernel " UTS_RELEASE "\n");
	bootx_printf("\nlinked at        : 0x%x", KERNELBASE);
	bootx_printf("\nframe buffer at  : 0x%x", bi->dispDeviceBase);
	bootx_printf(" (phys), 0x%x", bi->logicalDisplayBase);
	bootx_printf(" (log)");
	bootx_printf("\nklimit           : 0x%x",(unsigned long)klimit);
	bootx_printf("\nboot_info at     : 0x%x", bi);
	__asm__ __volatile__ ("mfmsr %0" : "=r" (flags));
	bootx_printf("\nMSR              : 0x%x", flags);
	__asm__ __volatile__ ("mfspr %0, 287" : "=r" (pvr));
	bootx_printf("\nPVR              : 0x%x", pvr);
	pvr >>= 16;
	if (pvr > 1) {
	    __asm__ __volatile__ ("mfspr %0, 1008" : "=r" (flags));
	    bootx_printf("\nHID0             : 0x%x", flags);
	}
	if (pvr == 8 || pvr == 12 || pvr == 0x800c) {
	    __asm__ __volatile__ ("mfspr %0, 1019" : "=r" (flags));
	    bootx_printf("\nICTC             : 0x%x", flags);
	}
#ifdef DEBUG
	bootx_printf("\n\n");
	bootx_printf("bi->deviceTreeOffset   : 0x%x\n",
		     bi->deviceTreeOffset);
	bootx_printf("bi->deviceTreeSize     : 0x%x\n",
		     bi->deviceTreeSize);
#endif
	bootx_printf("\n\n");
}
#endif /* CONFIG_BOOTX_TEXT */

void __init bootx_init(unsigned long r3, unsigned long r4)
{
	boot_infos_t *bi = (boot_infos_t *) r4;
	unsigned long hdr;
	unsigned long space;
	unsigned long ptr, x;
	char *model;
	unsigned long offset = reloc_offset();

	reloc_got2(offset);

	bootx_info = bi;

	/* We haven't cleared any bss at this point, make sure
	 * what we need is initialized
	 */
	bootx_dt_strbase = bootx_dt_strend = 0;
	bootx_node_chosen = 0;
	bootx_disp_path[0] = 0;

	if (!BOOT_INFO_IS_V2_COMPATIBLE(bi))
		bi->logicalDisplayBase = bi->dispDeviceBase;

	/* Fixup depth 16 -> 15 as that's what MacOS calls 16bpp */
	if (bi->dispDeviceDepth == 16)
		bi->dispDeviceDepth = 15;


#ifdef CONFIG_BOOTX_TEXT
	ptr = (unsigned long)bi->logicalDisplayBase;
	ptr += bi->dispDeviceRect[1] * bi->dispDeviceRowBytes;
	ptr += bi->dispDeviceRect[0] * ((bi->dispDeviceDepth + 7) / 8);
	btext_setup_display(bi->dispDeviceRect[2] - bi->dispDeviceRect[0],
			    bi->dispDeviceRect[3] - bi->dispDeviceRect[1],
			    bi->dispDeviceDepth, bi->dispDeviceRowBytes,
			    (unsigned long)bi->logicalDisplayBase);
	btext_clearscreen();
	btext_flushscreen();
#endif /* CONFIG_BOOTX_TEXT */

	/*
	 * Test if boot-info is compatible.  Done only in config
	 * CONFIG_BOOTX_TEXT since there is nothing much we can do
	 * with an incompatible version, except display a message
	 * and eventually hang the processor...
	 *
	 * I'll try to keep enough of boot-info compatible in the
	 * future to always allow display of this message;
	 */
	if (!BOOT_INFO_IS_COMPATIBLE(bi)) {
		bootx_printf(" !!! WARNING - Incompatible version"
			     " of BootX !!!\n\n\n");
		for (;;)
			;
	}
	if (bi->architecture != BOOT_ARCH_PCI) {
		bootx_printf(" !!! WARNING - Usupported machine"
			     " architecture !\n");
		for (;;)
			;
	}

#ifdef CONFIG_BOOTX_TEXT
	btext_welcome(bi);
#endif

	/* New BootX enters kernel with MMU off, i/os are not allowed
	 * here. This hack will have been done by the boostrap anyway.
	 */
	if (bi->version < 4) {
		/*
		 * XXX If this is an iMac, turn off the USB controller.
		 */
		model = (char *) bootx_early_getprop(r4 + bi->deviceTreeOffset,
						     4, "model");
		if (model
		    && (strcmp(model, "iMac,1") == 0
			|| strcmp(model, "PowerMac1,1") == 0)) {
			bootx_printf("iMac,1 detected, shutting down USB \n");
			out_le32((unsigned __iomem *)0x80880008, 1);	/* XXX */
		}
	}

	/* Get a pointer that points above the device tree, args, ramdisk,
	 * etc... to use for generating the flattened tree
	 */
	if (bi->version < 5) {
		space = bi->deviceTreeOffset + bi->deviceTreeSize;
		if (bi->ramDisk >= space)
			space = bi->ramDisk + bi->ramDiskSize;
	} else
		space = bi->totalParamsSize;

	bootx_printf("Total space used by parameters & ramdisk: 0x%x \n", space);

	/* New BootX will have flushed all TLBs and enters kernel with
	 * MMU switched OFF, so this should not be useful anymore.
	 */
	if (bi->version < 4) {
		bootx_printf("Touching pages...\n");

		/*
		 * Touch each page to make sure the PTEs for them
		 * are in the hash table - the aim is to try to avoid
		 * getting DSI exceptions while copying the kernel image.
		 */
		for (ptr = ((unsigned long) &_stext) & PAGE_MASK;
		     ptr < (unsigned long)bi + space; ptr += PAGE_SIZE)
			x = *(volatile unsigned long *)ptr;
	}

	/* Ok, now we need to generate a flattened device-tree to pass
	 * to the kernel
	 */
	bootx_printf("Preparing boot params...\n");

	hdr = bootx_flatten_dt(space);

#ifdef CONFIG_BOOTX_TEXT
#ifdef SET_BOOT_BAT
	bootx_printf("Preparing BAT...\n");
	btext_prepare_BAT();
#else
	btext_unmap();
#endif
#endif

	reloc_got2(-offset);

	__start(hdr, KERNELBASE + offset, 0);
}