linux/arch/powerpc/boot/prom.c

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/*
* Copyright (C) Paul Mackerras 1997.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <stdarg.h>
#include <stddef.h>
#include "string.h"
#include "stdio.h"
#include "prom.h"
int (*prom)(void *);
phandle chosen_handle;
ihandle stdout;
int call_prom(const char *service, int nargs, int nret, ...)
{
int i;
struct prom_args {
const char *service;
int nargs;
int nret;
unsigned int args[12];
} args;
va_list list;
args.service = service;
args.nargs = nargs;
args.nret = nret;
va_start(list, nret);
for (i = 0; i < nargs; i++)
args.args[i] = va_arg(list, unsigned int);
va_end(list);
for (i = 0; i < nret; i++)
args.args[nargs+i] = 0;
if (prom(&args) < 0)
return -1;
return (nret > 0)? args.args[nargs]: 0;
}
int call_prom_ret(const char *service, int nargs, int nret,
unsigned int *rets, ...)
{
int i;
struct prom_args {
const char *service;
int nargs;
int nret;
unsigned int args[12];
} args;
va_list list;
args.service = service;
args.nargs = nargs;
args.nret = nret;
va_start(list, rets);
for (i = 0; i < nargs; i++)
args.args[i] = va_arg(list, unsigned int);
va_end(list);
for (i = 0; i < nret; i++)
args.args[nargs+i] = 0;
if (prom(&args) < 0)
return -1;
if (rets != (void *) 0)
for (i = 1; i < nret; ++i)
rets[i-1] = args.args[nargs+i];
return (nret > 0)? args.args[nargs]: 0;
}
int write(void *handle, void *ptr, int nb)
{
return call_prom("write", 3, 1, handle, ptr, nb);
}
/*
* Older OF's require that when claiming a specific range of addresses,
* we claim the physical space in the /memory node and the virtual
* space in the chosen mmu node, and then do a map operation to
* map virtual to physical.
*/
static int need_map = -1;
static ihandle chosen_mmu;
static phandle memory;
/* returns true if s2 is a prefix of s1 */
static int string_match(const char *s1, const char *s2)
{
for (; *s2; ++s2)
if (*s1++ != *s2)
return 0;
return 1;
}
static int check_of_version(void)
{
phandle oprom, chosen;
char version[64];
oprom = finddevice("/openprom");
if (oprom == (phandle) -1)
return 0;
if (getprop(oprom, "model", version, sizeof(version)) <= 0)
return 0;
version[sizeof(version)-1] = 0;
printf("OF version = '%s'\r\n", version);
if (!string_match(version, "Open Firmware, 1.")
&& !string_match(version, "FirmWorks,3."))
return 0;
chosen = finddevice("/chosen");
if (chosen == (phandle) -1) {
chosen = finddevice("/chosen@0");
if (chosen == (phandle) -1) {
printf("no chosen\n");
return 0;
}
}
if (getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
printf("no mmu\n");
return 0;
}
memory = (ihandle) call_prom("open", 1, 1, "/memory");
if (memory == (ihandle) -1) {
memory = (ihandle) call_prom("open", 1, 1, "/memory@0");
if (memory == (ihandle) -1) {
printf("no memory node\n");
return 0;
}
}
printf("old OF detected\r\n");
return 1;
}
void *claim(unsigned long virt, unsigned long size, unsigned long align)
{
int ret;
unsigned int result;
if (need_map < 0)
need_map = check_of_version();
if (align || !need_map)
return (void *) call_prom("claim", 3, 1, virt, size, align);
ret = call_prom_ret("call-method", 5, 2, &result, "claim", memory,
align, size, virt);
if (ret != 0 || result == -1)
return (void *) -1;
ret = call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
align, size, virt);
/* 0x12 == coherent + read/write */
ret = call_prom("call-method", 6, 1, "map", chosen_mmu,
0x12, size, virt, virt);
return (void *) virt;
}