arch/openrisc/kernel/setup.c - maze/linux - Git at Google

 /*
  * OpenRISC setup.c
  *
  * Linux architectural port borrowing liberally from similar works of
  * others.  All original copyrights apply as per the original source
  * declaration.
  *
  * Modifications for the OpenRISC architecture:
  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  *
  *      This program is free software; you can redistribute it and/or
  *      modify it under the terms of the GNU General Public License
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  *
  * This file handles the architecture-dependent parts of initialization
  */

 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/console.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/seq_file.h>
 #include <linux/serial.h>
 #include <linux/initrd.h>
 #include <linux/of_fdt.h>
 #include <linux/of.h>
 #include <linux/memblock.h>
 #include <linux/device.h>
 #include <linux/of_platform.h>

 #include <asm/segment.h>
 #include <asm/pgtable.h>
 #include <asm/types.h>
 #include <asm/setup.h>
 #include <asm/io.h>
 #include <asm/cpuinfo.h>
 #include <asm/delay.h>

 #include "vmlinux.h"

 char __initdata cmd_line[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;

 static unsigned long __init setup_memory(void)
 {
 	unsigned long bootmap_size;
 	unsigned long ram_start_pfn;
 	unsigned long free_ram_start_pfn;
 	unsigned long ram_end_pfn;
 	phys_addr_t memory_start, memory_end;
 	struct memblock_region *region;

 	memory_end = memory_start = 0;

 	/* Find main memory where is the kernel */
 	for_each_memblock(memory, region) {
 		memory_start = region->base;
 		memory_end = region->base + region->size;
 		printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
 		       memory_start, memory_end);
 	}

 	if (!memory_end) {
 		panic("No memory!");
 	}

 	ram_start_pfn = PFN_UP(memory_start);
 	/* free_ram_start_pfn is first page after kernel */
 	free_ram_start_pfn = PFN_UP(__pa(&_end));
 	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

 	max_pfn = ram_end_pfn;

 	/*
 	 * initialize the boot-time allocator (with low memory only).
 	 *
 	 * This makes the memory from the end of the kernel to the end of
 	 * RAM usable.
 	 * init_bootmem sets the global values min_low_pfn, max_low_pfn.
 	 */
 	bootmap_size = init_bootmem(free_ram_start_pfn,
 				    ram_end_pfn - ram_start_pfn);
 	free_bootmem(PFN_PHYS(free_ram_start_pfn),
 		     (ram_end_pfn - free_ram_start_pfn) << PAGE_SHIFT);
 	reserve_bootmem(PFN_PHYS(free_ram_start_pfn), bootmap_size,
 			BOOTMEM_DEFAULT);

 	for_each_memblock(reserved, region) {
 		printk(KERN_INFO "Reserved - 0x%08x-0x%08x\n",
 		       (u32) region->base, (u32) region->size);
 		reserve_bootmem(region->base, region->size, BOOTMEM_DEFAULT);
 	}

 	return ram_end_pfn;
 }

 struct cpuinfo cpuinfo;

 static void print_cpuinfo(void)
 {
 	unsigned long upr = mfspr(SPR_UPR);
 	unsigned long vr = mfspr(SPR_VR);
 	unsigned int version;
 	unsigned int revision;

 	version = (vr & SPR_VR_VER) >> 24;
 	revision = (vr & SPR_VR_REV);

 	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
 	       version, revision, cpuinfo.clock_frequency / 1000000);

 	if (!(upr & SPR_UPR_UP)) {
 		printk(KERN_INFO
 		       "-- no UPR register... unable to detect configuration\n");
 		return;
 	}

 	if (upr & SPR_UPR_DCP)
 		printk(KERN_INFO
 		       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
 		       cpuinfo.dcache_size, cpuinfo.dcache_block_size, 1);
 	else
 		printk(KERN_INFO "-- dcache disabled\n");
 	if (upr & SPR_UPR_ICP)
 		printk(KERN_INFO
 		       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
 		       cpuinfo.icache_size, cpuinfo.icache_block_size, 1);
 	else
 		printk(KERN_INFO "-- icache disabled\n");

 	if (upr & SPR_UPR_DMP)
 		printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
 		       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
 		       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
 	if (upr & SPR_UPR_IMP)
 		printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
 		       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
 		       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));

 	printk(KERN_INFO "-- additional features:\n");
 	if (upr & SPR_UPR_DUP)
 		printk(KERN_INFO "-- debug unit\n");
 	if (upr & SPR_UPR_PCUP)
 		printk(KERN_INFO "-- performance counters\n");
 	if (upr & SPR_UPR_PMP)
 		printk(KERN_INFO "-- power management\n");
 	if (upr & SPR_UPR_PICP)
 		printk(KERN_INFO "-- PIC\n");
 	if (upr & SPR_UPR_TTP)
 		printk(KERN_INFO "-- timer\n");
 	if (upr & SPR_UPR_CUP)
 		printk(KERN_INFO "-- custom unit(s)\n");
 }

 void __init setup_cpuinfo(void)
 {
 	struct device_node *cpu;
 	unsigned long iccfgr, dccfgr;
 	unsigned long cache_set_size, cache_ways;

 	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
 	if (!cpu)
 		panic("No compatible CPU found in device tree...\n");

 	iccfgr = mfspr(SPR_ICCFGR);
 	cache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
 	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
 	cpuinfo.icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
 	cpuinfo.icache_size =
 	    cache_set_size * cache_ways * cpuinfo.icache_block_size;

 	dccfgr = mfspr(SPR_DCCFGR);
 	cache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
 	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
 	cpuinfo.dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
 	cpuinfo.dcache_size =
 	    cache_set_size * cache_ways * cpuinfo.dcache_block_size;

 	if (of_property_read_u32(cpu, "clock-frequency",
 				 &cpuinfo.clock_frequency)) {
 		printk(KERN_WARNING
 		       "Device tree missing CPU 'clock-frequency' parameter."
 		       "Assuming frequency 25MHZ"
 		       "This is probably not what you want.");
 	}

 	of_node_put(cpu);

 	print_cpuinfo();
 }

 /**
  * or32_early_setup
  *
  * Handles the pointer to the device tree that this kernel is to use
  * for establishing the available platform devices.
  *
  * Falls back on built-in device tree in case null pointer is passed.
  */

 void __init or32_early_setup(unsigned int fdt)
 {
 	if (fdt) {
 		early_init_devtree((void*) fdt);
 		printk(KERN_INFO "FDT at 0x%08x\n", fdt);
 	} else {
 		early_init_devtree(__dtb_start);
 		printk(KERN_INFO "Compiled-in FDT at %p\n", __dtb_start);
 	}
 }

 static int __init openrisc_device_probe(void)
 {
 	of_platform_populate(NULL, NULL, NULL, NULL);

 	return 0;
 }

 device_initcall(openrisc_device_probe);

 static inline unsigned long extract_value_bits(unsigned long reg,
 					       short bit_nr, short width)
 {
 	return (reg >> bit_nr) & (0 << width);
 }

 static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
 {
 	while (!(mask & 0x1)) {
 		reg = reg >> 1;
 		mask = mask >> 1;
 	}
 	return mask & reg;
 }

 void __init detect_unit_config(unsigned long upr, unsigned long mask,
 			       char *text, void (*func) (void))
 {
 	if (text != NULL)
 		printk("%s", text);

 	if (upr & mask) {
 		if (func != NULL)
 			func();
 		else
 			printk("present\n");
 	} else
 		printk("not present\n");
 }

 /*
  * calibrate_delay
  *
  * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
  * from the clock frequency passed in via the device tree
  *
  */

 void __cpuinit calibrate_delay(void)
 {
 	const int *val;
 	struct device_node *cpu = NULL;
 	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
 	val = of_get_property(cpu, "clock-frequency", NULL);
 	if (!val)
 		panic("no cpu 'clock-frequency' parameter in device tree");
 	loops_per_jiffy = *val / HZ;
 	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
 		loops_per_jiffy / (500000 / HZ),
 		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
 }

 void __init setup_arch(char **cmdline_p)
 {
 	unsigned long max_low_pfn;

 	unflatten_device_tree();

 	setup_cpuinfo();

 	/* process 1's initial memory region is the kernel code/data */
 	init_mm.start_code = (unsigned long)&_stext;
 	init_mm.end_code = (unsigned long)&_etext;
 	init_mm.end_data = (unsigned long)&_edata;
 	init_mm.brk = (unsigned long)&_end;

 #ifdef CONFIG_BLK_DEV_INITRD
 	initrd_start = (unsigned long)&__initrd_start;
 	initrd_end = (unsigned long)&__initrd_end;
 	if (initrd_start == initrd_end) {
 		initrd_start = 0;
 		initrd_end = 0;
 	}
 	initrd_below_start_ok = 1;
 #endif

 	/* setup bootmem allocator */
 	max_low_pfn = setup_memory();

 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();

 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
 	if (!conswitchp)
 		conswitchp = &dummy_con;
 #endif

 	*cmdline_p = cmd_line;

 	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.net\n");
 }

 static int show_cpuinfo(struct seq_file *m, void *v)
 {
 	unsigned long vr;
 	int version, revision;

 	vr = mfspr(SPR_VR);
 	version = (vr & SPR_VR_VER) >> 24;
 	revision = vr & SPR_VR_REV;

 	return seq_printf(m,
 			  "cpu\t\t: OpenRISC-%x\n"
 			  "revision\t: %d\n"
 			  "frequency\t: %ld\n"
 			  "dcache size\t: %d bytes\n"
 			  "dcache block size\t: %d bytes\n"
 			  "icache size\t: %d bytes\n"
 			  "icache block size\t: %d bytes\n"
 			  "immu\t\t: %d entries, %lu ways\n"
 			  "dmmu\t\t: %d entries, %lu ways\n"
 			  "bogomips\t: %lu.%02lu\n",
 			  version,
 			  revision,
 			  loops_per_jiffy * HZ,
 			  cpuinfo.dcache_size,
 			  cpuinfo.dcache_block_size,
 			  cpuinfo.icache_size,
 			  cpuinfo.icache_block_size,
 			  1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
 			  1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),
 			  1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
 			  1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),
 			  (loops_per_jiffy * HZ) / 500000,
 			  ((loops_per_jiffy * HZ) / 5000) % 100);
 }

 static void *c_start(struct seq_file *m, loff_t * pos)
 {
 	/* We only have one CPU... */
 	return *pos < 1 ? (void *)1 : NULL;
 }

 static void *c_next(struct seq_file *m, void *v, loff_t * pos)
 {
 	++*pos;
 	return NULL;
 }

 static void c_stop(struct seq_file *m, void *v)
 {
 }

 const struct seq_operations cpuinfo_op = {
 	.start = c_start,
 	.next = c_next,
 	.stop = c_stop,
 	.show = show_cpuinfo,
 };
	/*
	* OpenRISC setup.c
	*
	* Linux architectural port borrowing liberally from similar works of
	* others. All original copyrights apply as per the original source
	* declaration.
	*
	* Modifications for the OpenRISC architecture:
	* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
	* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	* This file handles the architecture-dependent parts of initialization
	*/

	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/ptrace.h>
	#include <linux/slab.h>
	#include <linux/tty.h>
	#include <linux/ioport.h>
	#include <linux/delay.h>
	#include <linux/console.h>
	#include <linux/init.h>
	#include <linux/bootmem.h>
	#include <linux/seq_file.h>
	#include <linux/serial.h>
	#include <linux/initrd.h>
	#include <linux/of_fdt.h>
	#include <linux/of.h>
	#include <linux/memblock.h>
	#include <linux/device.h>
	#include <linux/of_platform.h>

	#include <asm/segment.h>
	#include <asm/pgtable.h>
	#include <asm/types.h>
	#include <asm/setup.h>
	#include <asm/io.h>
	#include <asm/cpuinfo.h>
	#include <asm/delay.h>

	#include "vmlinux.h"

	char __initdata cmd_line[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;

	static unsigned long __init setup_memory(void)
	{
	unsigned long bootmap_size;
	unsigned long ram_start_pfn;
	unsigned long free_ram_start_pfn;
	unsigned long ram_end_pfn;
	phys_addr_t memory_start, memory_end;
	struct memblock_region *region;

	memory_end = memory_start = 0;

	/* Find main memory where is the kernel */
	for_each_memblock(memory, region) {
	memory_start = region->base;
	memory_end = region->base + region->size;
	printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
	memory_start, memory_end);
	}

	if (!memory_end) {
	panic("No memory!");
	}

	ram_start_pfn = PFN_UP(memory_start);
	/* free_ram_start_pfn is first page after kernel */
	free_ram_start_pfn = PFN_UP(__pa(&_end));
	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

	max_pfn = ram_end_pfn;

	/*
	* initialize the boot-time allocator (with low memory only).
	*
	* This makes the memory from the end of the kernel to the end of
	* RAM usable.
	* init_bootmem sets the global values min_low_pfn, max_low_pfn.
	*/
	bootmap_size = init_bootmem(free_ram_start_pfn,
	ram_end_pfn - ram_start_pfn);
	free_bootmem(PFN_PHYS(free_ram_start_pfn),
	(ram_end_pfn - free_ram_start_pfn) << PAGE_SHIFT);
	reserve_bootmem(PFN_PHYS(free_ram_start_pfn), bootmap_size,
	BOOTMEM_DEFAULT);

	for_each_memblock(reserved, region) {
	printk(KERN_INFO "Reserved - 0x%08x-0x%08x\n",
	(u32) region->base, (u32) region->size);
	reserve_bootmem(region->base, region->size, BOOTMEM_DEFAULT);
	}

	return ram_end_pfn;
	}

	struct cpuinfo cpuinfo;

	static void print_cpuinfo(void)
	{
	unsigned long upr = mfspr(SPR_UPR);
	unsigned long vr = mfspr(SPR_VR);
	unsigned int version;
	unsigned int revision;

	version = (vr & SPR_VR_VER) >> 24;
	revision = (vr & SPR_VR_REV);

	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
	version, revision, cpuinfo.clock_frequency / 1000000);

	if (!(upr & SPR_UPR_UP)) {
	printk(KERN_INFO
	"-- no UPR register... unable to detect configuration\n");
	return;
	}

	if (upr & SPR_UPR_DCP)
	printk(KERN_INFO
	"-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
	cpuinfo.dcache_size, cpuinfo.dcache_block_size, 1);
	else
	printk(KERN_INFO "-- dcache disabled\n");
	if (upr & SPR_UPR_ICP)
	printk(KERN_INFO
	"-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
	cpuinfo.icache_size, cpuinfo.icache_block_size, 1);
	else
	printk(KERN_INFO "-- icache disabled\n");

	if (upr & SPR_UPR_DMP)
	printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
	1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
	if (upr & SPR_UPR_IMP)
	printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
	1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));

	printk(KERN_INFO "-- additional features:\n");
	if (upr & SPR_UPR_DUP)
	printk(KERN_INFO "-- debug unit\n");
	if (upr & SPR_UPR_PCUP)
	printk(KERN_INFO "-- performance counters\n");
	if (upr & SPR_UPR_PMP)
	printk(KERN_INFO "-- power management\n");
	if (upr & SPR_UPR_PICP)
	printk(KERN_INFO "-- PIC\n");
	if (upr & SPR_UPR_TTP)
	printk(KERN_INFO "-- timer\n");
	if (upr & SPR_UPR_CUP)
	printk(KERN_INFO "-- custom unit(s)\n");
	}

	void __init setup_cpuinfo(void)
	{
	struct device_node *cpu;
	unsigned long iccfgr, dccfgr;
	unsigned long cache_set_size, cache_ways;

	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
	if (!cpu)
	panic("No compatible CPU found in device tree...\n");

	iccfgr = mfspr(SPR_ICCFGR);
	cache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
	cpuinfo.icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
	cpuinfo.icache_size =
	cache_set_size * cache_ways * cpuinfo.icache_block_size;

	dccfgr = mfspr(SPR_DCCFGR);
	cache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
	cpuinfo.dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
	cpuinfo.dcache_size =
	cache_set_size * cache_ways * cpuinfo.dcache_block_size;

	if (of_property_read_u32(cpu, "clock-frequency",
	&cpuinfo.clock_frequency)) {
	printk(KERN_WARNING
	"Device tree missing CPU 'clock-frequency' parameter."
	"Assuming frequency 25MHZ"
	"This is probably not what you want.");
	}

	of_node_put(cpu);

	print_cpuinfo();
	}

	/**
	* or32_early_setup
	*
	* Handles the pointer to the device tree that this kernel is to use
	* for establishing the available platform devices.
	*
	* Falls back on built-in device tree in case null pointer is passed.
	*/

	void __init or32_early_setup(unsigned int fdt)
	{
	if (fdt) {
	early_init_devtree((void*) fdt);
	printk(KERN_INFO "FDT at 0x%08x\n", fdt);
	} else {
	early_init_devtree(__dtb_start);
	printk(KERN_INFO "Compiled-in FDT at %p\n", __dtb_start);
	}
	}

	static int __init openrisc_device_probe(void)
	{
	of_platform_populate(NULL, NULL, NULL, NULL);

	return 0;
	}

	device_initcall(openrisc_device_probe);

	static inline unsigned long extract_value_bits(unsigned long reg,
	short bit_nr, short width)
	{
	return (reg >> bit_nr) & (0 << width);
	}

	static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
	{
	while (!(mask & 0x1)) {
	reg = reg >> 1;
	mask = mask >> 1;
	}
	return mask & reg;
	}

	void __init detect_unit_config(unsigned long upr, unsigned long mask,
	char text, void (func) (void))
	{
	if (text != NULL)
	printk("%s", text);

	if (upr & mask) {
	if (func != NULL)
	func();
	else
	printk("present\n");
	} else
	printk("not present\n");
	}

	/*
	* calibrate_delay
	*
	* Lightweight calibrate_delay implementation that calculates loops_per_jiffy
	* from the clock frequency passed in via the device tree
	*
	*/

	void __cpuinit calibrate_delay(void)
	{
	const int *val;
	struct device_node *cpu = NULL;
	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
	val = of_get_property(cpu, "clock-frequency", NULL);
	if (!val)
	panic("no cpu 'clock-frequency' parameter in device tree");
	loops_per_jiffy = *val / HZ;
	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
	loops_per_jiffy / (500000 / HZ),
	(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
	}

	void __init setup_arch(char **cmdline_p)
	{
	unsigned long max_low_pfn;

	unflatten_device_tree();

	setup_cpuinfo();

	/* process 1's initial memory region is the kernel code/data */
	init_mm.start_code = (unsigned long)&_stext;
	init_mm.end_code = (unsigned long)&_etext;
	init_mm.end_data = (unsigned long)&_edata;
	init_mm.brk = (unsigned long)&_end;

	#ifdef CONFIG_BLK_DEV_INITRD
	initrd_start = (unsigned long)&__initrd_start;
	initrd_end = (unsigned long)&__initrd_end;
	if (initrd_start == initrd_end) {
	initrd_start = 0;
	initrd_end = 0;
	}
	initrd_below_start_ok = 1;
	#endif

	/* setup bootmem allocator */
	max_low_pfn = setup_memory();

	/* paging_init() sets up the MMU and marks all pages as reserved */
	paging_init();

	#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
	if (!conswitchp)
	conswitchp = &dummy_con;
	#endif

	*cmdline_p = cmd_line;

	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.net\n");
	}

	static int show_cpuinfo(struct seq_file m, void v)
	{
	unsigned long vr;
	int version, revision;

	vr = mfspr(SPR_VR);
	version = (vr & SPR_VR_VER) >> 24;
	revision = vr & SPR_VR_REV;

	return seq_printf(m,
	"cpu\t\t: OpenRISC-%x\n"
	"revision\t: %d\n"
	"frequency\t: %ld\n"
	"dcache size\t: %d bytes\n"
	"dcache block size\t: %d bytes\n"
	"icache size\t: %d bytes\n"
	"icache block size\t: %d bytes\n"
	"immu\t\t: %d entries, %lu ways\n"
	"dmmu\t\t: %d entries, %lu ways\n"
	"bogomips\t: %lu.%02lu\n",
	version,
	revision,
	loops_per_jiffy * HZ,
	cpuinfo.dcache_size,
	cpuinfo.dcache_block_size,
	cpuinfo.icache_size,
	cpuinfo.icache_block_size,
	1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),
	1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),
	(loops_per_jiffy * HZ) / 500000,
	((loops_per_jiffy * HZ) / 5000) % 100);
	}

	static void c_start(struct seq_file m, loff_t * pos)
	{
	/* We only have one CPU... */
	return pos < 1 ? (void )1 : NULL;
	}

	static void c_next(struct seq_file m, void v, loff_t pos)
	{
	++*pos;
	return NULL;
	}

	static void c_stop(struct seq_file m, void v)
	{
	}

	const struct seq_operations cpuinfo_op = {
	.start = c_start,
	.next = c_next,
	.stop = c_stop,
	.show = show_cpuinfo,
	};