2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
17 #include <linux/kernel.h>
18 #include <linux/string.h>
19 #include <linux/init.h>
20 #include <linux/threads.h>
21 #include <linux/spinlock.h>
22 #include <linux/types.h>
23 #include <linux/pci.h>
24 #include <linux/stringify.h>
25 #include <linux/delay.h>
26 #include <linux/initrd.h>
27 #include <linux/bitops.h>
28 #include <linux/module.h>
29 #include <linux/kexec.h>
30 #include <linux/debugfs.h>
31 #include <linux/irq.h>
32 #include <linux/memblock.h>
36 #include <asm/processor.h>
39 #include <asm/system.h>
41 #include <asm/pgtable.h>
42 #include <asm/sections.h>
43 #include <asm/pci-bridge.h>
45 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
47 memblock_add(base, size);
50 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
52 return __va(memblock_alloc(size, align));
55 #ifdef CONFIG_EARLY_PRINTK
58 int __init early_init_dt_scan_chosen_serial(unsigned long node,
59 const char *uname, int depth, void *data)
64 pr_debug("%s: depth: %d, uname: %s\n", __func__, depth, uname);
66 if (depth == 1 && (strcmp(uname, "chosen") == 0 ||
67 strcmp(uname, "chosen@0") == 0)) {
68 p = of_get_flat_dt_prop(node, "linux,stdout-path", &l);
69 if (p != NULL && l > 0)
70 stdout = p; /* store pointer to stdout-path */
73 if (stdout && strstr(stdout, uname)) {
74 p = of_get_flat_dt_prop(node, "compatible", &l);
75 pr_debug("Compatible string: %s\n", p);
77 if ((strncmp(p, "xlnx,xps-uart16550", 18) == 0) ||
78 (strncmp(p, "xlnx,axi-uart16550", 18) == 0)) {
81 *(u32 *)data = UART16550;
83 addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l);
84 addr += *(u32 *)of_get_flat_dt_prop(node,
86 /* clear register offset */
87 return be32_to_cpu(addr) & ~3;
89 if ((strncmp(p, "xlnx,xps-uartlite", 17) == 0) ||
90 (strncmp(p, "xlnx,opb-uartlite", 17) == 0) ||
91 (strncmp(p, "xlnx,axi-uartlite", 17) == 0)) {
94 *(u32 *)data = UARTLITE;
96 addrp = of_get_flat_dt_prop(node, "reg", &l);
97 return be32_to_cpup(addrp); /* return address */
103 /* this function is looking for early console - Microblaze specific */
104 int __init of_early_console(void *version)
106 return of_scan_flat_dt(early_init_dt_scan_chosen_serial, version);
110 void __init early_init_devtree(void *params)
112 pr_debug(" -> early_init_devtree(%p)\n", params);
114 /* Setup flat device-tree pointer */
115 initial_boot_params = params;
117 /* Retrieve various informations from the /chosen node of the
118 * device-tree, including the platform type, initrd location and
119 * size, TCE reserve, and more ...
121 of_scan_flat_dt(early_init_dt_scan_chosen, cmd_line);
123 /* Scan memory nodes and rebuild MEMBLOCKs */
125 of_scan_flat_dt(early_init_dt_scan_root, NULL);
126 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
128 /* Save command line for /proc/cmdline and then parse parameters */
129 strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
134 pr_debug("Phys. mem: %lx\n", (unsigned long) memblock_phys_mem_size());
136 pr_debug(" <- early_init_devtree()\n");
139 #ifdef CONFIG_BLK_DEV_INITRD
140 void __init early_init_dt_setup_initrd_arch(unsigned long start,
143 initrd_start = (unsigned long)__va(start);
144 initrd_end = (unsigned long)__va(end);
145 initrd_below_start_ok = 1;
151 * New implementation of the OF "find" APIs, return a refcounted
152 * object, call of_node_put() when done. The device tree and list
153 * are protected by a rw_lock.
155 * Note that property management will need some locking as well,
156 * this isn't dealt with yet.
160 #if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
161 static struct debugfs_blob_wrapper flat_dt_blob;
163 static int __init export_flat_device_tree(void)
167 flat_dt_blob.data = initial_boot_params;
168 flat_dt_blob.size = initial_boot_params->totalsize;
170 d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
171 of_debugfs_root, &flat_dt_blob);
177 device_initcall(export_flat_device_tree);