oflib.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 <stddef.h>
#include "types.h"
#include "elf.h"
#include "string.h"
#include "stdio.h"
#include "page.h"
#include "ops.h"

#include "of.h"

static int (*prom) (void *);

void of_init(void *promptr)
{
    prom = (int (*)(void *))promptr;
}

int of_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;
}

static int of_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;
}

/* 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;
}

/*
 * 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;

static int check_of_version(void)
{
    phandle oprom, chosen;
    char version[64];

    oprom = of_finddevice("/openprom");
    if (oprom == (phandle) -1)
        return 0;
    if (of_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 = of_finddevice("/chosen");
    if (chosen == (phandle) -1) {
        chosen = of_finddevice("/chosen@0");
        if (chosen == (phandle) -1) {
            printf("no chosen\n");
            return 0;
        }
    }
    if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
        printf("no mmu\n");
        return 0;
    }
    memory = (ihandle) of_call_prom("open", 1, 1, "/memory");
    if (memory == (ihandle) -1) {
        memory = (ihandle) of_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 *of_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 *) of_call_prom("claim", 3, 1, virt, size, align);

    ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
                   align, size, virt);
    if (ret != 0 || result == -1)
        return (void *) -1;
    ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
                   align, size, virt);
    /* 0x12 == coherent + read/write */
    ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
               0x12, size, virt, virt);
    return (void *) virt;
}

void *of_vmlinux_alloc(unsigned long size)
{
    unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
    void *addr;
    void *p;

    /* With some older POWER4 firmware we need to claim the area the kernel
     * will reside in.  Newer firmwares don't need this so we just ignore
     * the return value.
     */
    addr = of_claim(start, end - start, 0);
    printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %p\r\n",
           start, end, end - start, addr);

    p = malloc(size);
    if (!p)
        fatal("Can't allocate memory for kernel image!\n\r");

    return p;
}

void of_exit(void)
{
    of_call_prom("exit", 0, 0);
}

/*
 * OF device tree routines
 */
void *of_finddevice(const char *name)
{
    return (phandle) of_call_prom("finddevice", 1, 1, name);
}

int of_getprop(const void *phandle, const char *name, void *buf,
           const int buflen)
{
    return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
}

int of_setprop(const void *phandle, const char *name, const void *buf,
           const int buflen)
{
    return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
}