prom.c

Go to the documentation of this file.

/*
 *  RouterBoard 500 specific prom routines
 *
 *  Copyright (C) 2003, Peter Sadik <[email protected]>
 *  Copyright (C) 2005-2006, P.Christeas <[email protected]>
 *  Copyright (C) 2007, Gabor Juhos <[email protected]>
 *          Felix Fietkau <[email protected]>
 *          Florian Fainelli <[email protected]>
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the
 *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA  02110-1301, USA.
 *
 */

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/console.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/blkdev.h>

#include <asm/bootinfo.h>
#include <asm/mach-rc32434/ddr.h>
#include <asm/mach-rc32434/prom.h>

unsigned int idt_cpu_freq = 132000000;
EXPORT_SYMBOL(idt_cpu_freq);

static struct resource ddr_reg[] = {
    {
        .name = "ddr-reg",
        .start = DDR0_PHYS_ADDR,
        .end = DDR0_PHYS_ADDR + sizeof(struct ddr_ram),
        .flags = IORESOURCE_MEM,
    }
};

void __init prom_free_prom_memory(void)
{
    /* No prom memory to free */
}

static inline int match_tag(char *arg, const char *tag)
{
    return strncmp(arg, tag, strlen(tag)) == 0;
}

static inline unsigned long tag2ul(char *arg, const char *tag)
{
    char *num;

    num = arg + strlen(tag);
    return simple_strtoul(num, 0, 10);
}

void __init prom_setup_cmdline(void)
{
    static char cmd_line[COMMAND_LINE_SIZE] __initdata;
    char *cp, *board;
    int prom_argc;
    char **prom_argv, **prom_envp;
    int i;

    prom_argc = fw_arg0;
    prom_argv = (char **) fw_arg1;
    prom_envp = (char **) fw_arg2;

    cp = cmd_line;
        /* Note: it is common that parameters start
         * at argv[1] and not argv[0],
         * however, our elf loader starts at [0] */
    for (i = 0; i < prom_argc; i++) {
        if (match_tag(prom_argv[i], FREQ_TAG)) {
            idt_cpu_freq = tag2ul(prom_argv[i], FREQ_TAG);
            continue;
        }
#ifdef IGNORE_CMDLINE_MEM
        /* parses out the "mem=xx" arg */
        if (match_tag(prom_argv[i], MEM_TAG))
            continue;
#endif
        if (i > 0)
            *(cp++) = ' ';
        if (match_tag(prom_argv[i], BOARD_TAG)) {
            board = prom_argv[i] + strlen(BOARD_TAG);

            if (match_tag(board, BOARD_RB532A))
                mips_machtype = MACH_MIKROTIK_RB532A;
            else
                mips_machtype = MACH_MIKROTIK_RB532;
        }

        strcpy(cp, prom_argv[i]);
        cp += strlen(prom_argv[i]);
    }
    *(cp++) = ' ';

    i = strlen(arcs_cmdline);
    if (i > 0) {
        *(cp++) = ' ';
        strcpy(cp, arcs_cmdline);
        cp += strlen(arcs_cmdline);
    }
    cmd_line[COMMAND_LINE_SIZE - 1] = '\0';

    strcpy(arcs_cmdline, cmd_line);
}

void __init prom_init(void)
{
    struct ddr_ram __iomem *ddr;
    phys_t memsize;
    phys_t ddrbase;

    ddr = ioremap_nocache(ddr_reg[0].start,
            ddr_reg[0].end - ddr_reg[0].start);

    if (!ddr) {
        printk(KERN_ERR "Unable to remap DDR register\n");
        return;
    }

    ddrbase = (phys_t)&ddr->ddrbase;
    memsize = (phys_t)&ddr->ddrmask;
    memsize = 0 - memsize;

    prom_setup_cmdline();

    /* give all RAM to boot allocator,
     * except for the first 0x400 and the last 0x200 bytes */
    add_memory_region(ddrbase + 0x400, memsize - 0x600, BOOT_MEM_RAM);
}