arch/powerpc/boot/of.c

   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(u32 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_exit(void)
 212 {
 213         call_prom("exit", 0, 0);
 214 }
 215
 216 /*
 217  * OF device tree routines
 218  */
 219 static void *of_finddevice(const char *name)
 220 {
 221         return (phandle) call_prom("finddevice", 1, 1, name);
 222 }
 223
 224 static int of_getprop(const void *phandle, const char *name, void *buf,
 225                 const int buflen)
 226 {
 227         return call_prom("getprop", 4, 1, phandle, name, buf, buflen);
 228 }
 229
 230 static int of_setprop(const void *phandle, const char *name, const void *buf,
 231                 const int buflen)
 232 {
 233         return call_prom("setprop", 4, 1, phandle, name, buf, buflen);
 234 }
 235
 236 /*
 237  * OF console routines
 238  */
 239 static void *of_stdout_handle;
 240
 241 static int of_console_open(void)
 242 {
 243         void *devp;
 244
 245         if (((devp = finddevice("/chosen")) != NULL)
 246                         && (getprop(devp, "stdout", &of_stdout_handle,
 247                                 sizeof(of_stdout_handle))
 248                                 == sizeof(of_stdout_handle)))
 249                 return 0;
 250
 251         return -1;
 252 }
 253
 254 static void of_console_write(char *buf, int len)
 255 {
 256         call_prom("write", 3, 1, of_stdout_handle, buf, len);
 257 }
 258
 259 int platform_init(void *promptr, char *dt_blob_start, char *dt_blob_end)
 260 {
 261         platform_ops.image_hdr = of_image_hdr;
 262         platform_ops.malloc = of_try_claim;
 263         platform_ops.exit = of_exit;
 264
 265         dt_ops.finddevice = of_finddevice;
 266         dt_ops.getprop = of_getprop;
 267         dt_ops.setprop = of_setprop;
 268
 269         console_ops.open = of_console_open;
 270         console_ops.write = of_console_write;
 271
 272         prom = (int (*)(void *))promptr;
 273         return 0;
 274 }