second/file.c

/*
 *  file.c - Filesystem related interfaces
 *
 *  Copyright (C) 2001 Ethan Benson
 *
 *  parse_device_path()
 *
 *  Copyright (C) 2001 Colin Walters
 *
 *  Copyright (C) 1999 Benjamin Herrenschmidt
 *
 *  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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "ctype.h"
#include "types.h"
#include "stddef.h"
#include "stdlib.h"
#include "file.h"
#include "prom.h"
#include "string.h"
#include "partition.h"
#include "fs.h"
#include "errors.h"
#include "debug.h"

extern char bootdevice[1024];

/* This function follows the device path in the devtree and separates
   the device name, partition number, and other datas (mostly file name)
   the string passed in parameters is changed since 0 are put in place
   of some separators to terminate the various strings.  

   when a default device is supplied imagepath will be assumed to be a
   plain filename unless it contains a : otherwise if defaultdev is
   NULL imagepath will be assumed to be a device path.

   returns 1 on success 0 on failure.

   Supported examples:
    - /pci@80000000/pci-bridge@d/ADPT,2930CU@2/@1:4
    - /pci@80000000/pci-bridge@d/ADPT,2930CU@2/@1:4,/boot/vmlinux
    - hd:3,/boot/vmlinux
    - enet:10.0.0.1,/tftpboot/vmlinux
    - enet:,/tftpboot/vmlinux
    - enet:bootp
    - enet:0
   Supported only if defdevice == NULL
    - disc
    - any other device path lacking a :
   Unsupported examples:
    - hd:2,\\:tbxi <- no filename will be detected due to the extra :
    - enet:192.168.2.1,bootme,c-iaddr,g-iaddr,subnet-mask,bootp-retries,tftp-retries */

int
parse_device_path(char *imagepath, char *defdevice, int defpart,
		  char *deffile, struct boot_fspec_t *result)
{
     char *ptr;
     char *ipath = NULL;
     char *defdev = NULL;

     result->dev = NULL;
     result->part = -1;
     result->file = NULL;

     if (!imagepath)
	  return 0;
     else
	  ipath = strdup(imagepath);

     if (defdevice)
	  defdev = strdup(defdevice);

     if (defdev) {
	  if (!strstr(defdev, "ethernet") && !strstr(defdev, "enet")) {
	       if ((ptr = strrchr(defdev, ':')) != NULL)
		    *ptr = 0; /* remove trailing : from defdevice if necessary */
	  }
     }

     /* if there is no : then there is no filename or partition.  must
        use strrchr() since enet:,10.0.0.1,file is legal */

     if (strchr(ipath, ':') != NULL) {
	  if ((ptr = strrchr(ipath, ',')) != NULL) {
	       char *colon = strrchr(ipath, ':');
	       /* If a ':' occurs *after* a ',', then we assume that there is
		  no filename */
	       if (!colon || colon < ptr) {
		    result->file = strdup(ptr+1);
		    /* Trim the filename off */
		    *ptr = 0;
	       }
	  }
     }

     if (strstr(ipath, "ethernet") || strstr(ipath, "enet"))
	  if ((ptr = strstr(ipath, "bootp")) != NULL) { /* `n' key booting boots enet:bootp */
	       *ptr = 0;
	       result->dev = strdup(ipath);
	  } else
	       result->dev = strdup(ipath);
     else if ((ptr = strchr(ipath, ':')) != NULL) {
	  *ptr = 0;
	  result->dev = strdup(ipath);
	  if (*(ptr+1))
	       result->part = simple_strtol(ptr+1, NULL, 10);
     } else if (!defdev) {
	  result->dev = strdup(ipath); 
     } else if (strlen(ipath)) {
          result->file = strdup(ipath);
     } else {
	  return 0;
     }

     if (!result->dev && defdev)
	  result->dev = strdup(defdev);
     
     if (result->part < 0)
	  result->part = defpart;
     
     if (!result->file)
	  result->file = strdup(deffile);

     free(ipath);
     if (defdev)
	  free(defdev);
     return 1;
}


static int
file_block_open(	struct boot_file_t*	file,
			const char*		dev_name,
			const char*		file_name,
			int			partition)
{
     struct partition_t*	parts;
     struct partition_t*	p;
     struct partition_t*	found;
	
     parts = partitions_lookup(dev_name);
     found = NULL;
			
#if DEBUG
     if (parts)
	  prom_printf("partitions:\n");
     else
	  prom_printf("no partitions found.\n");
#endif
     for (p = parts; p && !found; p=p->next) {
	  DEBUG_F("number: %02d, start: 0x%08lx, length: 0x%08lx\n",
		  p->part_number, p->part_start, p->part_size );
	  if (partition == -1) {
	       file->fs = fs_open( file, dev_name, p, file_name );
	       if (file->fs != NULL)
		    goto bail;
	  }
	  if ((partition >= 0) && (partition == p->part_number))
	       found = p;
#if DEBUG
	  if (found)
	       prom_printf(" (match)\n");
#endif						
     }

     /* Note: we don't skip when found is NULL since we can, in some
      * cases, let OF figure out a default partition.
      */
     DEBUG_F( "Using OF defaults.. (found = %p)\n", found );
     file->fs = fs_open( file, dev_name, found, file_name );

bail:
     if (parts)
	  partitions_free(parts);

     return fserrorno;
}

static int
file_net_open(	struct boot_file_t*	file,
		const char*		dev_name,
		const char*		file_name)
{
     file->fs = fs_of_netboot;
     return fs_of_netboot->open(file, dev_name, NULL, file_name);
}

static int
default_read(	struct boot_file_t*	file,
		unsigned int		size,
		void*			buffer)
{
     prom_printf("WARNING ! default_read called !\n");
     return FILE_ERR_EOF;
}

static int
default_seek(	struct boot_file_t*	file,
		unsigned int		newpos)
{
     prom_printf("WARNING ! default_seek called !\n");
     return FILE_ERR_EOF;
}

static int
default_close(	struct boot_file_t*	file)
{
     prom_printf("WARNING ! default_close called !\n");
     return FILE_ERR_OK;
}

static struct fs_t fs_default =
{
     "defaults",
     NULL,
     default_read,
     default_seek,
     default_close
};


int open_file(const struct boot_fspec_t* spec, struct boot_file_t* file)
{
     int result;
	
     memset(file, 0, sizeof(struct boot_file_t*));
     file->fs        = &fs_default;

     DEBUG_F("dev_path = %s\nfile_name = %s\npartition = %d\n",
	     spec->dev, spec->file, spec->part);

     result = prom_get_devtype(spec->dev);
     if (result > 0)
	  file->device_kind = result;
     else
	  return result;
	
     switch(file->device_kind) {
     case FILE_DEVICE_BLOCK:
	  DEBUG_F("device is a block device\n");
	  return file_block_open(file, spec->dev, spec->file, spec->part);
     case FILE_DEVICE_NET:
	  DEBUG_F("device is a network device\n");
	  return file_net_open(file, spec->dev, spec->file);
     }
     return 0;
}

/* 
 * Local variables:
 * c-file-style: "k&r"
 * c-basic-offset: 5
 * End:
 */