/* * srm_env.c - Access to SRM environment * variables through linux' procfs * * Copyright (C) 2001-2002 Jan-Benedict Glaw * * This driver is at all a modified version of Erik Mouw's * Documentation/DocBook/procfs_example.c, so: thank * you, Erik! He can be reached via email at * . It is based on an idea * provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They * included a patch like this as well. Thanks for idea! * * This program is free software; you can redistribute * it and/or modify it under the terms of the GNU General * Public License version 2 as published by the Free Software * Foundation. * * 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 * */ /* * Changelog * ~~~~~~~~~ * * Thu, 22 Aug 2002 15:10:43 +0200 * - Update Config.help entry. I got a number of emails asking * me to tell their senders if they could make use of this * piece of code... So: "SRM is something like BIOS for your * Alpha" * - Update code formatting a bit to better conform CodingStyle * rules. * - So this is v0.0.5, with no changes (except formatting) * * Wed, 22 May 2002 00:11:21 +0200 * - Fix typo on comment (SRC -> SRM) * - Call this "Version 0.0.4" * * Tue, 9 Apr 2002 18:44:40 +0200 * - Implement access by variable name and additionally * by number. This is done by creating two subdirectories * where one holds all names (like the old directory * did) and the other holding 256 files named like "0", * "1" and so on. * - Call this "Version 0.0.3" * */ #include #include #include #include #include #include #include #define BASE_DIR "srm_environment" /* Subdir in /proc/ */ #define NAMED_DIR "named_variables" /* Subdir for known variables */ #define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */ #define VERSION "0.0.5" /* Module version */ #define NAME "srm_env" /* Module name */ MODULE_AUTHOR("Jan-Benedict Glaw "); MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface"); MODULE_LICENSE("GPL"); typedef struct _srm_env { char *name; unsigned long id; struct proc_dir_entry *proc_entry; } srm_env_t; static struct proc_dir_entry *base_dir; static struct proc_dir_entry *named_dir; static struct proc_dir_entry *numbered_dir; static char number[256][4]; static srm_env_t srm_named_entries[] = { { "auto_action", ENV_AUTO_ACTION }, { "boot_dev", ENV_BOOT_DEV }, { "bootdef_dev", ENV_BOOTDEF_DEV }, { "booted_dev", ENV_BOOTED_DEV }, { "boot_file", ENV_BOOT_FILE }, { "booted_file", ENV_BOOTED_FILE }, { "boot_osflags", ENV_BOOT_OSFLAGS }, { "booted_osflags", ENV_BOOTED_OSFLAGS }, { "boot_reset", ENV_BOOT_RESET }, { "dump_dev", ENV_DUMP_DEV }, { "enable_audit", ENV_ENABLE_AUDIT }, { "license", ENV_LICENSE }, { "char_set", ENV_CHAR_SET }, { "language", ENV_LANGUAGE }, { "tty_dev", ENV_TTY_DEV }, { NULL, 0 }, }; static srm_env_t srm_numbered_entries[256]; static int srm_env_read(char *page, char **start, off_t off, int count, int *eof, void *data) { int nbytes; unsigned long ret; srm_env_t *entry; if(off != 0) return -EFAULT; entry = (srm_env_t *) data; ret = callback_getenv(entry->id, page, count); if((ret >> 61) == 0) nbytes = (int) ret; else nbytes = -EFAULT; return nbytes; } static int srm_env_write(struct file *file, const char __user *buffer, unsigned long count, void *data) { int res; srm_env_t *entry; char *buf = (char *) __get_free_page(GFP_USER); unsigned long ret1, ret2; entry = (srm_env_t *) data; if (!buf) return -ENOMEM; res = -EINVAL; if (count >= PAGE_SIZE) goto out; res = -EFAULT; if (copy_from_user(buf, buffer, count)) goto out; buf[count] = '\0'; ret1 = callback_setenv(entry->id, buf, count); if ((ret1 >> 61) == 0) { do ret2 = callback_save_env(); while((ret2 >> 61) == 1); res = (int) ret1; } out: free_page((unsigned long)buf); return res; } static void srm_env_cleanup(void) { srm_env_t *entry; unsigned long var_num; if(base_dir) { /* * Remove named entries */ if(named_dir) { entry = srm_named_entries; while(entry->name != NULL && entry->id != 0) { if(entry->proc_entry) { remove_proc_entry(entry->name, named_dir); entry->proc_entry = NULL; } entry++; } remove_proc_entry(NAMED_DIR, base_dir); } /* * Remove numbered entries */ if(numbered_dir) { for(var_num = 0; var_num <= 255; var_num++) { entry = &srm_numbered_entries[var_num]; if(entry->proc_entry) { remove_proc_entry(entry->name, numbered_dir); entry->proc_entry = NULL; entry->name = NULL; } } remove_proc_entry(NUMBERED_DIR, base_dir); } remove_proc_entry(BASE_DIR, NULL); } return; } static int __init srm_env_init(void) { srm_env_t *entry; unsigned long var_num; /* * Check system */ if(!alpha_using_srm) { printk(KERN_INFO "%s: This Alpha system doesn't " "know about SRM (or you've booted " "SRM->MILO->Linux, which gets " "misdetected)...\n", __FUNCTION__); return -ENODEV; } /* * Init numbers */ for(var_num = 0; var_num <= 255; var_num++) sprintf(number[var_num], "%ld", var_num); /* * Create base directory */ base_dir = proc_mkdir(BASE_DIR, NULL); if(base_dir == NULL) { printk(KERN_ERR "Couldn't create base dir /proc/%s\n", BASE_DIR); goto cleanup; } base_dir->owner = THIS_MODULE; /* * Create per-name subdirectory */ named_dir = proc_mkdir(NAMED_DIR, base_dir); if(named_dir == NULL) { printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", BASE_DIR, NAMED_DIR); goto cleanup; } named_dir->owner = THIS_MODULE; /* * Create per-number subdirectory */ numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir); if(numbered_dir == NULL) { printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", BASE_DIR, NUMBERED_DIR); goto cleanup; } numbered_dir->owner = THIS_MODULE; /* * Create all named nodes */ entry = srm_named_entries; while(entry->name != NULL && entry->id != 0) { entry->proc_entry = create_proc_entry(entry->name, 0644, named_dir); if(entry->proc_entry == NULL) goto cleanup; entry->proc_entry->data = (void *) entry; entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; entry++; } /* * Create all numbered nodes */ for(var_num = 0; var_num <= 255; var_num++) { entry = &srm_numbered_entries[var_num]; entry->name = number[var_num]; entry->proc_entry = create_proc_entry(entry->name, 0644, numbered_dir); if(entry->proc_entry == NULL) goto cleanup; entry->id = var_num; entry->proc_entry->data = (void *) entry; entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; } printk(KERN_INFO "%s: version %s loaded successfully\n", NAME, VERSION); return 0; cleanup: srm_env_cleanup(); return -ENOMEM; } static void __exit srm_env_exit(void) { srm_env_cleanup(); printk(KERN_INFO "%s: unloaded successfully\n", NAME); return; } module_init(srm_env_init); module_exit(srm_env_exit);