xref: /openbmc/linux/arch/powerpc/boot/of.c (revision 64c70b1c)
1 /*
2  * Copyright (C) Paul Mackerras 1997.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 #include <stdarg.h>
10 #include <stddef.h>
11 #include "types.h"
12 #include "elf.h"
13 #include "string.h"
14 #include "stdio.h"
15 #include "page.h"
16 #include "ops.h"
17 
18 typedef void *ihandle;
19 typedef void *phandle;
20 
21 extern char _end[];
22 
23 /* Value picked to match that used by yaboot */
24 #define PROG_START	0x01400000	/* only used on 64-bit systems */
25 #define RAM_END		(512<<20)	/* Fixme: use OF */
26 #define	ONE_MB		0x100000
27 
28 int (*prom) (void *);
29 
30 
31 static unsigned long claim_base;
32 
33 static int call_prom(const char *service, int nargs, int nret, ...)
34 {
35 	int i;
36 	struct prom_args {
37 		const char *service;
38 		int nargs;
39 		int nret;
40 		unsigned int args[12];
41 	} args;
42 	va_list list;
43 
44 	args.service = service;
45 	args.nargs = nargs;
46 	args.nret = nret;
47 
48 	va_start(list, nret);
49 	for (i = 0; i < nargs; i++)
50 		args.args[i] = va_arg(list, unsigned int);
51 	va_end(list);
52 
53 	for (i = 0; i < nret; i++)
54 		args.args[nargs+i] = 0;
55 
56 	if (prom(&args) < 0)
57 		return -1;
58 
59 	return (nret > 0)? args.args[nargs]: 0;
60 }
61 
62 static int call_prom_ret(const char *service, int nargs, int nret,
63 		  unsigned int *rets, ...)
64 {
65 	int i;
66 	struct prom_args {
67 		const char *service;
68 		int nargs;
69 		int nret;
70 		unsigned int args[12];
71 	} args;
72 	va_list list;
73 
74 	args.service = service;
75 	args.nargs = nargs;
76 	args.nret = nret;
77 
78 	va_start(list, rets);
79 	for (i = 0; i < nargs; i++)
80 		args.args[i] = va_arg(list, unsigned int);
81 	va_end(list);
82 
83 	for (i = 0; i < nret; i++)
84 		args.args[nargs+i] = 0;
85 
86 	if (prom(&args) < 0)
87 		return -1;
88 
89 	if (rets != (void *) 0)
90 		for (i = 1; i < nret; ++i)
91 			rets[i-1] = args.args[nargs+i];
92 
93 	return (nret > 0)? args.args[nargs]: 0;
94 }
95 
96 /*
97  * Older OF's require that when claiming a specific range of addresses,
98  * we claim the physical space in the /memory node and the virtual
99  * space in the chosen mmu node, and then do a map operation to
100  * map virtual to physical.
101  */
102 static int need_map = -1;
103 static ihandle chosen_mmu;
104 static phandle memory;
105 
106 /* returns true if s2 is a prefix of s1 */
107 static int string_match(const char *s1, const char *s2)
108 {
109 	for (; *s2; ++s2)
110 		if (*s1++ != *s2)
111 			return 0;
112 	return 1;
113 }
114 
115 static int check_of_version(void)
116 {
117 	phandle oprom, chosen;
118 	char version[64];
119 
120 	oprom = finddevice("/openprom");
121 	if (oprom == (phandle) -1)
122 		return 0;
123 	if (getprop(oprom, "model", version, sizeof(version)) <= 0)
124 		return 0;
125 	version[sizeof(version)-1] = 0;
126 	printf("OF version = '%s'\r\n", version);
127 	if (!string_match(version, "Open Firmware, 1.")
128 	    && !string_match(version, "FirmWorks,3."))
129 		return 0;
130 	chosen = finddevice("/chosen");
131 	if (chosen == (phandle) -1) {
132 		chosen = finddevice("/chosen@0");
133 		if (chosen == (phandle) -1) {
134 			printf("no chosen\n");
135 			return 0;
136 		}
137 	}
138 	if (getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
139 		printf("no mmu\n");
140 		return 0;
141 	}
142 	memory = (ihandle) call_prom("open", 1, 1, "/memory");
143 	if (memory == (ihandle) -1) {
144 		memory = (ihandle) call_prom("open", 1, 1, "/memory@0");
145 		if (memory == (ihandle) -1) {
146 			printf("no memory node\n");
147 			return 0;
148 		}
149 	}
150 	printf("old OF detected\r\n");
151 	return 1;
152 }
153 
154 static void *claim(unsigned long virt, unsigned long size, unsigned long align)
155 {
156 	int ret;
157 	unsigned int result;
158 
159 	if (need_map < 0)
160 		need_map = check_of_version();
161 	if (align || !need_map)
162 		return (void *) call_prom("claim", 3, 1, virt, size, align);
163 
164 	ret = call_prom_ret("call-method", 5, 2, &result, "claim", memory,
165 			    align, size, virt);
166 	if (ret != 0 || result == -1)
167 		return (void *) -1;
168 	ret = call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
169 			    align, size, virt);
170 	/* 0x12 == coherent + read/write */
171 	ret = call_prom("call-method", 6, 1, "map", chosen_mmu,
172 			0x12, size, virt, virt);
173 	return (void *) virt;
174 }
175 
176 static void *of_try_claim(unsigned long size)
177 {
178 	unsigned long addr = 0;
179 
180 	if (claim_base == 0)
181 		claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);
182 
183 	for(; claim_base < RAM_END; claim_base += ONE_MB) {
184 #ifdef DEBUG
185 		printf("    trying: 0x%08lx\n\r", claim_base);
186 #endif
187 		addr = (unsigned long)claim(claim_base, size, 0);
188 		if ((void *)addr != (void *)-1)
189 			break;
190 	}
191 	if (addr == 0)
192 		return NULL;
193 	claim_base = PAGE_ALIGN(claim_base + size);
194 	return (void *)addr;
195 }
196 
197 static void of_image_hdr(const void *hdr)
198 {
199 	const Elf64_Ehdr *elf64 = hdr;
200 
201 	if (elf64->e_ident[EI_CLASS] == ELFCLASS64) {
202 		/*
203 		 * Maintain a "magic" minimum address. This keeps some older
204 		 * firmware platforms running.
205 		 */
206 		if (claim_base < PROG_START)
207 			claim_base = PROG_START;
208 	}
209 }
210 
211 static void *of_vmlinux_alloc(unsigned long size)
212 {
213 	void *p = malloc(size);
214 
215 	if (!p)
216 		fatal("Can't allocate memory for kernel image!\n\r");
217 
218 	return p;
219 }
220 
221 static void of_exit(void)
222 {
223 	call_prom("exit", 0, 0);
224 }
225 
226 /*
227  * OF device tree routines
228  */
229 static void *of_finddevice(const char *name)
230 {
231 	return (phandle) call_prom("finddevice", 1, 1, name);
232 }
233 
234 static int of_getprop(const void *phandle, const char *name, void *buf,
235 		const int buflen)
236 {
237 	return call_prom("getprop", 4, 1, phandle, name, buf, buflen);
238 }
239 
240 static int of_setprop(const void *phandle, const char *name, const void *buf,
241 		const int buflen)
242 {
243 	return call_prom("setprop", 4, 1, phandle, name, buf, buflen);
244 }
245 
246 /*
247  * OF console routines
248  */
249 static void *of_stdout_handle;
250 
251 static int of_console_open(void)
252 {
253 	void *devp;
254 
255 	if (((devp = finddevice("/chosen")) != NULL)
256 			&& (getprop(devp, "stdout", &of_stdout_handle,
257 				sizeof(of_stdout_handle))
258 				== sizeof(of_stdout_handle)))
259 		return 0;
260 
261 	return -1;
262 }
263 
264 static void of_console_write(char *buf, int len)
265 {
266 	call_prom("write", 3, 1, of_stdout_handle, buf, len);
267 }
268 
269 void platform_init(unsigned long a1, unsigned long a2, void *promptr)
270 {
271 	platform_ops.image_hdr = of_image_hdr;
272 	platform_ops.malloc = of_try_claim;
273 	platform_ops.exit = of_exit;
274 	platform_ops.vmlinux_alloc = of_vmlinux_alloc;
275 
276 	dt_ops.finddevice = of_finddevice;
277 	dt_ops.getprop = of_getprop;
278 	dt_ops.setprop = of_setprop;
279 
280 	console_ops.open = of_console_open;
281 	console_ops.write = of_console_write;
282 
283 	prom = (int (*)(void *))promptr;
284 	loader_info.promptr = promptr;
285 	if (a1 && a2 && a2 != 0xdeadbeef) {
286 		loader_info.initrd_addr = a1;
287 		loader_info.initrd_size = a2;
288 	}
289 }
290