LXR linux/arch/mips/bcm47xx/prom.c

   1/*
   2 *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
   3 *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
   4 *
   5 *  This program is free software; you can redistribute  it and/or modify it
   6 *  under  the terms of  the GNU General  Public License as published by the
   7 *  Free Software Foundation;  either version 2 of the  License, or (at your
   8 *  option) any later version.
   9 *
  10 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  11 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  12 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  13 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  14 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  15 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  16 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  17 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  18 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  19 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  20 *
  21 *  You should have received a copy of the  GNU General Public License along
  22 *  with this program; if not, write  to the Free Software Foundation, Inc.,
  23 *  675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26#include <linux/init.h>
  27#include <linux/types.h>
  28#include <linux/kernel.h>
  29#include <linux/spinlock.h>
  30#include <asm/bootinfo.h>
  31#include <asm/fw/cfe/cfe_api.h>
  32#include <asm/fw/cfe/cfe_error.h>
  33
  34static int cfe_cons_handle;
  35
  36const char *get_system_type(void)
  37{
  38        return "Broadcom BCM47XX";
  39}
  40
  41void prom_putchar(char c)
  42{
  43        while (cfe_write(cfe_cons_handle, &c, 1) == 0)
  44                ;
  45}
  46
  47static __init void prom_init_cfe(void)
  48{
  49        uint32_t cfe_ept;
  50        uint32_t cfe_handle;
  51        uint32_t cfe_eptseal;
  52        int argc = fw_arg0;
  53        char **envp = (char **) fw_arg2;
  54        int *prom_vec = (int *) fw_arg3;
  55
  56        /*
  57         * Check if a loader was used; if NOT, the 4 arguments are
  58         * what CFE gives us (handle, 0, EPT and EPTSEAL)
  59         */
  60        if (argc < 0) {
  61                cfe_handle = (uint32_t)argc;
  62                cfe_ept = (uint32_t)envp;
  63                cfe_eptseal = (uint32_t)prom_vec;
  64        } else {
  65                if ((int)prom_vec < 0) {
  66                        /*
  67                         * Old loader; all it gives us is the handle,
  68                         * so use the "known" entrypoint and assume
  69                         * the seal.
  70                         */
  71                        cfe_handle = (uint32_t)prom_vec;
  72                        cfe_ept = 0xBFC00500;
  73                        cfe_eptseal = CFE_EPTSEAL;
  74                } else {
  75                        /*
  76                         * Newer loaders bundle the handle/ept/eptseal
  77                         * Note: prom_vec is in the loader's useg
  78                         * which is still alive in the TLB.
  79                         */
  80                        cfe_handle = prom_vec[0];
  81                        cfe_ept = prom_vec[2];
  82                        cfe_eptseal = prom_vec[3];
  83                }
  84        }
  85
  86        if (cfe_eptseal != CFE_EPTSEAL) {
  87                /* too early for panic to do any good */
  88                printk(KERN_ERR "CFE's entrypoint seal doesn't match.");
  89                while (1) ;
  90        }
  91
  92        cfe_init(cfe_handle, cfe_ept);
  93}
  94
  95static __init void prom_init_console(void)
  96{
  97        /* Initialize CFE console */
  98        cfe_cons_handle = cfe_getstdhandle(CFE_STDHANDLE_CONSOLE);
  99}
 100
 101static __init void prom_init_cmdline(void)
 102{
 103        static char buf[COMMAND_LINE_SIZE] __initdata;
 104
 105        /* Get the kernel command line from CFE */
 106        if (cfe_getenv("LINUX_CMDLINE", buf, COMMAND_LINE_SIZE) >= 0) {
 107                buf[COMMAND_LINE_SIZE - 1] = 0;
 108                strcpy(arcs_cmdline, buf);
 109        }
 110
 111        /* Force a console handover by adding a console= argument if needed,
 112         * as CFE is not available anymore later in the boot process. */
 113        if ((strstr(arcs_cmdline, "console=")) == NULL) {
 114                /* Try to read the default serial port used by CFE */
 115                if ((cfe_getenv("BOOT_CONSOLE", buf, COMMAND_LINE_SIZE) < 0)
 116                    || (strncmp("uart", buf, 4)))
 117                        /* Default to uart0 */
 118                        strcpy(buf, "uart0");
 119
 120                /* Compute the new command line */
 121                snprintf(arcs_cmdline, COMMAND_LINE_SIZE, "%s console=ttyS%c,115200",
 122                         arcs_cmdline, buf[4]);
 123        }
 124}
 125
 126static __init void prom_init_mem(void)
 127{
 128        unsigned long mem;
 129        unsigned long max;
 130
 131        /* Figure out memory size by finding aliases.
 132         *
 133         * We should theoretically use the mapping from CFE using cfe_enummem().
 134         * However as the BCM47XX is mostly used on low-memory systems, we
 135         * want to reuse the memory used by CFE (around 4MB). That means cfe_*
 136         * functions stop to work at some point during the boot, we should only
 137         * call them at the beginning of the boot.
 138         *
 139         * BCM47XX uses 128MB for addressing the ram, if the system contains
 140         * less that that amount of ram it remaps the ram more often into the
 141         * available space.
 142         * Accessing memory after 128MB will cause an exception.
 143         * max contains the biggest possible address supported by the platform.
 144         * If the method wants to try something above we assume 128MB ram.
 145         */
 146        max = ((unsigned long)(prom_init) | ((128 << 20) - 1));
 147        for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
 148                if (((unsigned long)(prom_init) + mem) > max) {
 149                        mem = (128 << 20);
 150                        printk(KERN_DEBUG "assume 128MB RAM\n");
 151                        break;
 152                }
 153                if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
 154                    *(unsigned long *)(prom_init))
 155                        break;
 156        }
 157
 158        add_memory_region(0, mem, BOOT_MEM_RAM);
 159}
 160
 161void __init prom_init(void)
 162{
 163        prom_init_cfe();
 164        prom_init_console();
 165        prom_init_cmdline();
 166        prom_init_mem();
 167}
 168
 169void __init prom_free_prom_memory(void)
 170{
 171}
 172