drivers/misc/cbmem_console.c

   1 /*
   2  * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
  16  */
  17
  18 #include <common.h>
  19
  20 #ifndef CONFIG_SYS_COREBOOT
  21 #error This driver requires coreboot
  22 #endif
  23
  24 #include <asm/arch/sysinfo.h>
  25
  26 struct cbmem_console {
  27         u32 buffer_size;
  28         u32 buffer_cursor;
  29         u8  buffer_body[0];
  30 }  __attribute__ ((__packed__));
  31
  32 static struct cbmem_console *cbmem_console_p;
  33
  34 void cbmemc_putc(char data)
  35 {
  36         int cursor;
  37
  38         cursor = cbmem_console_p->buffer_cursor++;
  39         if (cursor < cbmem_console_p->buffer_size)
  40                 cbmem_console_p->buffer_body[cursor] = data;
  41 }
  42
  43 void cbmemc_puts(const char *str)
  44 {
  45         char c;
  46
  47         while ((c = *str++) != 0)
  48                 cbmemc_putc(c);
  49 }
  50
  51 int cbmemc_init(void)
  52 {
  53         int rc;
  54         struct stdio_dev cons_dev;
  55         cbmem_console_p = lib_sysinfo.cbmem_cons;
  56
  57         memset(&cons_dev, 0, sizeof(cons_dev));
  58
  59         strcpy(cons_dev.name, "cbmem");
  60         cons_dev.flags = DEV_FLAGS_OUTPUT; /* Output only */
  61         cons_dev.putc  = cbmemc_putc;
  62         cons_dev.puts  = cbmemc_puts;
  63
  64         rc = stdio_register(&cons_dev);
  65
  66         return (rc == 0) ? 1 : rc;
  67 }