1/*
  2 *
  3 *  linux/arch/cris/kernel/setup.c
  4 *
  5 *  Copyright (C) 1995  Linus Torvalds
  6 *  Copyright (c) 2001  Axis Communications AB
  7 */
  8
  9/*
 10 * This file handles the architecture-dependent parts of initialization
 11 */
 12
 13#include <linux/init.h>
 14#include <linux/mm.h>
 15#include <linux/bootmem.h>
 16#include <asm/pgtable.h>
 17#include <linux/seq_file.h>
 18#include <linux/screen_info.h>
 19#include <linux/utsname.h>
 20#include <linux/pfn.h>
 21#include <linux/cpu.h>
 22#include <linux/of.h>
 23#include <linux/of_fdt.h>
 24#include <linux/of_platform.h>
 25#include <asm/setup.h>
 26#include <arch/system.h>
 27
 28/*
 29 * Setup options
 30 */
 31struct screen_info screen_info;
 32
 33extern int root_mountflags;
 34extern char _etext, _edata, _end;
 35
 36char __initdata cris_command_line[COMMAND_LINE_SIZE] = { 0, };
 37
 38extern const unsigned long text_start, edata; /* set by the linker script */
 39extern unsigned long dram_start, dram_end;
 40
 41extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */
 42
 43static struct cpu cpu_devices[NR_CPUS];
 44
 45extern void show_etrax_copyright(void);		/* arch-vX/kernel/setup.c */
 46
 47/* This mainly sets up the memory area, and can be really confusing.
 48 *
 49 * The physical DRAM is virtually mapped into dram_start to dram_end
 50 * (usually c0000000 to c0000000 + DRAM size). The physical address is
 51 * given by the macro __pa().
 52 *
 53 * In this DRAM, the kernel code and data is loaded, in the beginning.
 54 * It really starts at c0004000 to make room for some special pages -
 55 * the start address is text_start. The kernel data ends at _end. After
 56 * this the ROM filesystem is appended (if there is any).
 57 *
 58 * Between this address and dram_end, we have RAM pages usable to the
 59 * boot code and the system.
 60 *
 61 */
 62
 63void __init setup_arch(char **cmdline_p)
 64{
 65	extern void init_etrax_debug(void);
 66	unsigned long bootmap_size;
 67	unsigned long start_pfn, max_pfn;
 68	unsigned long memory_start;
 69
 70#ifdef CONFIG_OF
 71	early_init_dt_scan(__dtb_start);
 72#endif
 73
 74	/* register an initial console printing routine for printk's */
 75
 76	init_etrax_debug();
 77
 78	/* we should really poll for DRAM size! */
 79
 80	high_memory = &dram_end;
 81
 82	if(romfs_in_flash || !romfs_length) {
 83		/* if we have the romfs in flash, or if there is no rom filesystem,
 84		 * our free area starts directly after the BSS
 85		 */
 86		memory_start = (unsigned long) &_end;
 87	} else {
 88		/* otherwise the free area starts after the ROM filesystem */
 89		printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
 90		memory_start = romfs_start + romfs_length;
 91	}
 92
 93	/* process 1's initial memory region is the kernel code/data */
 94
 95	init_mm.start_code = (unsigned long) &text_start;
 96	init_mm.end_code =   (unsigned long) &_etext;
 97	init_mm.end_data =   (unsigned long) &_edata;
 98	init_mm.brk =        (unsigned long) &_end;
 99
100	/* min_low_pfn points to the start of DRAM, start_pfn points
101	 * to the first DRAM pages after the kernel, and max_low_pfn
102	 * to the end of DRAM.
103	 */
104
105        /*
106         * partially used pages are not usable - thus
107         * we are rounding upwards:
108         */
109
110        start_pfn = PFN_UP(memory_start);  /* usually c0000000 + kernel + romfs */
111	max_pfn =   PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
112
113        /*
114         * Initialize the boot-time allocator (start, end)
115	 *
116	 * We give it access to all our DRAM, but we could as well just have
117	 * given it a small slice. No point in doing that though, unless we
118	 * have non-contiguous memory and want the boot-stuff to be in, say,
119	 * the smallest area.
120	 *
121	 * It will put a bitmap of the allocated pages in the beginning
122	 * of the range we give it, but it won't mark the bitmaps pages
123	 * as reserved. We have to do that ourselves below.
124	 *
125	 * We need to use init_bootmem_node instead of init_bootmem
126	 * because our map starts at a quite high address (min_low_pfn).
127         */
128
129	max_low_pfn = max_pfn;
130	min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;
131
132	bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
133					 min_low_pfn,
134					 max_low_pfn);
135
136	/* And free all memory not belonging to the kernel (addr, size) */
137
138	free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));
139
140        /*
141         * Reserve the bootmem bitmap itself as well. We do this in two
142         * steps (first step was init_bootmem()) because this catches
143         * the (very unlikely) case of us accidentally initializing the
144         * bootmem allocator with an invalid RAM area.
145	 *
146	 * Arguments are start, size
147         */
148
149	reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size, BOOTMEM_DEFAULT);
150
151	unflatten_and_copy_device_tree();
152
153	/* paging_init() sets up the MMU and marks all pages as reserved */
154
155	paging_init();
156
157	*cmdline_p = cris_command_line;
158
159#ifdef CONFIG_ETRAX_CMDLINE
160        if (!strcmp(cris_command_line, "")) {
161		strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
162		cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
163	}
164#endif
165
166	/* Save command line for future references. */
167	memcpy(boot_command_line, cris_command_line, COMMAND_LINE_SIZE);
168	boot_command_line[COMMAND_LINE_SIZE - 1] = '\0';
169
170	/* give credit for the CRIS port */
171	show_etrax_copyright();
172
173	/* Setup utsname */
174	strcpy(init_utsname()->machine, cris_machine_name);
175}
176
177#ifdef CONFIG_PROC_FS
178static void *c_start(struct seq_file *m, loff_t *pos)
179{
180	return *pos < nr_cpu_ids ? (void *)(int)(*pos + 1) : NULL;
181}
182
183static void *c_next(struct seq_file *m, void *v, loff_t *pos)
184{
185	++*pos;
186	return c_start(m, pos);
187}
188
189static void c_stop(struct seq_file *m, void *v)
190{
191}
192
193extern int show_cpuinfo(struct seq_file *m, void *v);
194
195const struct seq_operations cpuinfo_op = {
196	.start = c_start,
197	.next  = c_next,
198	.stop  = c_stop,
199	.show  = show_cpuinfo,
200};
201#endif /* CONFIG_PROC_FS */
202
203static int __init topology_init(void)
204{
205	int i;
206
207	for_each_possible_cpu(i) {
208		 return register_cpu(&cpu_devices[i], i);
209	}
210
211	return 0;
212}
213
214subsys_initcall(topology_init);
215
216static int __init cris_of_init(void)
217{
218	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
219	return 0;
220}
221core_initcall(cris_of_init);