arch/powerpc/boot/oflib.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 <stddef.h>
  10 #include "types.h"
  11 #include "elf.h"
  12 #include "string.h"
  13 #include "stdio.h"
  14 #include "page.h"
  15 #include "ops.h"
  16
  17 #include "of.h"
  18
  19 typedef u32 prom_arg_t;
  20
  21 /* The following structure is used to communicate with open firmware.
  22  * All arguments in and out are in big endian format. */
  23 struct prom_args {
  24         __be32 service; /* Address of service name string. */
  25         __be32 nargs;   /* Number of input arguments. */
  26         __be32 nret;    /* Number of output arguments. */
  27         __be32 args[10];        /* Input/output arguments. */
  28 };
  29
  30 static int (*prom) (void *);
  31
  32 void of_init(void *promptr)
  33 {
  34         prom = (int (*)(void *))promptr;
  35 }
  36
  37 #define ADDR(x)         (u32)(unsigned long)(x)
  38
  39 int of_call_prom(const char *service, int nargs, int nret, ...)
  40 {
  41         int i;
  42         struct prom_args args;
  43         va_list list;
  44
  45         args.service = ADDR(service);
  46         args.nargs = nargs;
  47         args.nret = nret;
  48
  49         va_start(list, nret);
  50         for (i = 0; i < nargs; i++)
  51                 args.args[i] = va_arg(list, prom_arg_t);
  52         va_end(list);
  53
  54         for (i = 0; i < nret; i++)
  55                 args.args[nargs+i] = 0;
  56
  57         if (prom(&args) < 0)
  58                 return -1;
  59
  60         return (nret > 0)? args.args[nargs]: 0;
  61 }
  62
  63 static int of_call_prom_ret(const char *service, int nargs, int nret,
  64                             prom_arg_t *rets, ...)
  65 {
  66         int i;
  67         struct prom_args args;
  68         va_list list;
  69
  70         args.service = ADDR(service);
  71         args.nargs = nargs;
  72         args.nret = nret;
  73
  74         va_start(list, rets);
  75         for (i = 0; i < nargs; i++)
  76                 args.args[i] = va_arg(list, prom_arg_t);
  77         va_end(list);
  78
  79         for (i = 0; i < nret; i++)
  80                 args.args[nargs+i] = 0;
  81
  82         if (prom(&args) < 0)
  83                 return -1;
  84
  85         if (rets != (void *) 0)
  86                 for (i = 1; i < nret; ++i)
  87                         rets[i-1] = args.args[nargs+i];
  88
  89         return (nret > 0)? args.args[nargs]: 0;
  90 }
  91
  92 /* returns true if s2 is a prefix of s1 */
  93 static int string_match(const char *s1, const char *s2)
  94 {
  95         for (; *s2; ++s2)
  96                 if (*s1++ != *s2)
  97                         return 0;
  98         return 1;
  99 }
 100
 101 /*
 102  * Older OF's require that when claiming a specific range of addresses,
 103  * we claim the physical space in the /memory node and the virtual
 104  * space in the chosen mmu node, and then do a map operation to
 105  * map virtual to physical.
 106  */
 107 static int need_map = -1;
 108 static ihandle chosen_mmu;
 109 static phandle memory;
 110
 111 static int check_of_version(void)
 112 {
 113         phandle oprom, chosen;
 114         char version[64];
 115
 116         oprom = of_finddevice("/openprom");
 117         if (oprom == (phandle) -1)
 118                 return 0;
 119         if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
 120                 return 0;
 121         version[sizeof(version)-1] = 0;
 122         printf("OF version = '%s'\r\n", version);
 123         if (!string_match(version, "Open Firmware, 1.")
 124             && !string_match(version, "FirmWorks,3."))
 125                 return 0;
 126         chosen = of_finddevice("/chosen");
 127         if (chosen == (phandle) -1) {
 128                 chosen = of_finddevice("/chosen@0");
 129                 if (chosen == (phandle) -1) {
 130                         printf("no chosen\n");
 131                         return 0;
 132                 }
 133         }
 134         if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
 135                 printf("no mmu\n");
 136                 return 0;
 137         }
 138         memory = (ihandle) of_call_prom("open", 1, 1, "/memory");
 139         if (memory == (ihandle) -1) {
 140                 memory = (ihandle) of_call_prom("open", 1, 1, "/memory@0");
 141                 if (memory == (ihandle) -1) {
 142                         printf("no memory node\n");
 143                         return 0;
 144                 }
 145         }
 146         printf("old OF detected\r\n");
 147         return 1;
 148 }
 149
 150 void *of_claim(unsigned long virt, unsigned long size, unsigned long align)
 151 {
 152         int ret;
 153         prom_arg_t result;
 154
 155         if (need_map < 0)
 156                 need_map = check_of_version();
 157         if (align || !need_map)
 158                 return (void *) of_call_prom("claim", 3, 1, virt, size, align);
 159
 160         ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
 161                                align, size, virt);
 162         if (ret != 0 || result == -1)
 163                 return (void *) -1;
 164         ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
 165                                align, size, virt);
 166         /* 0x12 == coherent + read/write */
 167         ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
 168                            0x12, size, virt, virt);
 169         return (void *) virt;
 170 }
 171
 172 void *of_vmlinux_alloc(unsigned long size)
 173 {
 174         unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
 175         void *addr;
 176         void *p;
 177
 178         /* With some older POWER4 firmware we need to claim the area the kernel
 179          * will reside in.  Newer firmwares don't need this so we just ignore
 180          * the return value.
 181          */
 182         addr = of_claim(start, end - start, 0);
 183         printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %p\r\n",
 184                start, end, end - start, addr);
 185
 186         p = malloc(size);
 187         if (!p)
 188                 fatal("Can't allocate memory for kernel image!\n\r");
 189
 190         return p;
 191 }
 192
 193 void of_exit(void)
 194 {
 195         of_call_prom("exit", 0, 0);
 196 }
 197
 198 /*
 199  * OF device tree routines
 200  */
 201 void *of_finddevice(const char *name)
 202 {
 203         return (phandle) of_call_prom("finddevice", 1, 1, name);
 204 }
 205
 206 int of_getprop(const void *phandle, const char *name, void *buf,
 207                const int buflen)
 208 {
 209         return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
 210 }
 211
 212 int of_setprop(const void *phandle, const char *name, const void *buf,
 213                const int buflen)
 214 {
 215         return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
 216 }