/*
* Copyright (C) 2005 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <console/kconsole.h>
#include <console/console.h>
#include <console/chardev.h>
#include <print.h>
#include <panic.h>
#include <typedefs.h>
#include <arch/types.h>
#include <list.h>
#include <arch.h>
#include <func.h>
#include <macros.h>
#include <debug.h>
#define MAX_CMDLINE 256
/** Simple kernel console.
*
* The console is realized by kernel thread kconsole.
* It doesn't understand any useful command on its own,
* but makes it possible for other kernel subsystems to
* register their own commands.
*/
/** Locking.
*
* There is a list of cmd_info_t structures. This list
* is protected by cmd_lock spinlock. Note that specially
* the link elements of cmd_info_t are protected by
* this lock.
*
* Each cmd_info_t also has its own lock, which protects
* all elements thereof except the link element.
*
* cmd_lock must be acquired before any cmd_info lock.
* When locking two cmd info structures, structure with
* lower address must be locked first.
*/
spinlock_t cmd_lock; /**< Lock protecting command list. */
link_t cmd_head; /**< Command list. */
static cmd_info_t *parse_cmdline(char *cmdline, size_t len);
static bool parse_argument(char *cmdline, size_t len, index_t *start, index_t *end);
/** Data and methods for 'help' command. */
static int cmd_help(cmd_arg_t *argv);
static cmd_info_t help_info;
/** Data and methods for 'description' command. */
static int cmd_desc(cmd_arg_t *argv);
static void desc_help(void);
static cmd_info_t desc_info;
static char desc_buf[MAX_CMDLINE+1];
static cmd_arg_t desc_argv = {
.type = ARG_TYPE_STRING,
.buffer = desc_buf,
.len = sizeof(desc_buf)
};
/** Data and methods for 'halt' command. */
static int cmd_halt(cmd_arg_t *argv);
static cmd_info_t halt_info;
/** Initialize kconsole data structures. */
void kconsole_init(void)
{
spinlock_initialize(&cmd_lock, "kconsole_cmd");
list_initialize(&cmd_head);
help_info.name = "help";
help_info.description = "List supported commands.";
help_info.func = cmd_help;
help_info.help = NULL;
help_info.argc = 0;
help_info.argv = NULL;
spinlock_initialize(&help_info.lock, "kconsole_help");
link_initialize(&help_info.link);
if (!cmd_register(&help_info))
panic("could not register command %s\n", help_info.name);
desc_info.name = "describe";
desc_info.description = "Describe specified command.";
desc_info.help = desc_help;
desc_info.func = cmd_desc;
desc_info.argc = 1;
desc_info.argv = &desc_argv;
spinlock_initialize(&desc_info.lock, "kconsole_desc");
link_initialize(&desc_info.link);
if (!cmd_register(&desc_info))
panic("could not register command %s\n", desc_info.name);
halt_info.name = "halt";
halt_info.description = "Halt the kernel.";
halt_info.func = cmd_halt;
halt_info.help = NULL;
halt_info.argc = 0;
halt_info.argv = NULL;
spinlock_initialize(&halt_info.lock, "kconsole_halt");
link_initialize(&halt_info.link);
if (!cmd_register(&halt_info))
panic("could not register command %s\n", halt_info.name);
}
/** Register kconsole command.
*
* @param cmd Structure describing the command.
*
* @return 0 on failure, 1 on success.
*/
int cmd_register(cmd_info_t *cmd)
{
ipl_t ipl;
link_t *cur;
ipl = interrupts_disable();
spinlock_lock(&cmd_lock);
/*
* Make sure the command is not already listed.
*/
for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {
cmd_info_t *hlp;
hlp = list_get_instance(cur, cmd_info_t, link);
if (hlp == cmd) {
/* The command is already there. */
spinlock_unlock(&cmd_lock);
interrupts_restore(ipl);
return 0;
}
/* Avoid deadlock. */
if (hlp < cmd) {
spinlock_lock(&hlp->lock);
spinlock_lock(&cmd->lock);
} else {
spinlock_lock(&cmd->lock);
spinlock_lock(&hlp->lock);
}
/* The command is already there. */
spinlock_unlock(&hlp->lock);
spinlock_unlock(&cmd->lock);
spinlock_unlock(&cmd_lock);
interrupts_restore(ipl);
return 0;
}
spinlock_unlock(&hlp->lock);
spinlock_unlock(&cmd->lock);
}
/*
* Now the command can be added.
*/
list_append(&cmd->link, &cmd_head);
spinlock_unlock(&cmd_lock);
interrupts_restore(ipl);
return 1;
}
/** Kernel console managing thread.
*
* @param arg Not used.
*/
void kconsole(void *arg)
{
char cmdline[MAX_CMDLINE+1];
cmd_info_t *cmd_info;
count_t len;
if (!stdin) {
printf("%s: no stdin\n", __FUNCTION__
); return;
}
while (true) {
if (!(len
= gets(stdin
, cmdline
, sizeof(cmdline
)))) continue;
cmdline[len] = '\0';
cmd_info = parse_cmdline(cmdline, len);
if (!cmd_info)
continue;
(void) cmd_info->func(cmd_info->argv);
}
}
/** Parse command line.
*
* @param cmdline Command line as read from input device.
* @param len Command line length.
*
* @return Structure describing the command.
*/
cmd_info_t *parse_cmdline(char *cmdline, size_t len)
{
index_t start = 0, end = 0;
cmd_info_t *cmd = NULL;
link_t *cur;
ipl_t ipl;
int i;
if (!parse_argument(cmdline, len, &start, &end)) {
/* Command line did not contain alphanumeric word. */
return NULL;
}
ipl = interrupts_disable();
spinlock_lock(&cmd_lock);
for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {
cmd_info_t *hlp;
hlp = list_get_instance(cur, cmd_info_t, link);
spinlock_lock(&hlp->lock);
if (strncmp(hlp
->name
, &cmdline
[start
], (end
- start
) + 1) == 0) { cmd = hlp;
break;
}
spinlock_unlock(&hlp->lock);
}
spinlock_unlock(&cmd_lock);
if (!cmd) {
/* Unknown command. */
interrupts_restore(ipl);
return NULL;
}
/* cmd == hlp is locked */
/*
* The command line must be further analyzed and
* the parameters therefrom must be matched and
* converted to those specified in the cmd info
* structure.
*/
for (i = 0; i < cmd->argc; i++) {
char *buf;
start = end + 1;
if (!parse_argument(cmdline, len, &start, &end)) {
printf("Too few arguments.\n"); spinlock_unlock(&cmd->lock);
interrupts_restore(ipl);
return NULL;
}
switch (cmd->argv[i].type) {
case ARG_TYPE_STRING:
buf = cmd->argv[i].buffer;
strncpy(buf
, (const char *) &cmdline
[start
], min
((end
- start
) + 1, cmd
->argv
[i
].
len - 1)); buf[min((end - start) + 1, cmd->argv[i].len - 1)] = '\0';
break;
case ARG_TYPE_INT:
case ARG_TYPE_INVALID:
default:
panic("invalid argument type\n");
break;
}
}
start = end + 1;
if (parse_argument(cmdline, len, &start, &end)) {
printf("Too many arguments.\n"); spinlock_unlock(&cmd->lock);
interrupts_restore(ipl);
return NULL;
}
spinlock_unlock(&cmd->lock);
interrupts_restore(ipl);
return cmd;
}
/** Parse argument.
*
* Find start and end positions of command line argument.
*
* @param cmdline Command line as read from the input device.
* @param len Number of characters in cmdline.
* @param start On entry, 'start' contains pointer to the index
* of first unprocessed character of cmdline.
* On successful exit, it marks beginning of the next argument.
* @param end Undefined on entry. On exit, 'end' points to the last character
* of the next argument.
*
* @return false on failure, true on success.
*/
bool parse_argument(char *cmdline, size_t len, index_t *start, index_t *end)
{
int i;
bool found_start = false;
ASSERT(start != NULL);
ASSERT(end != NULL);
for (i = *start; i < len; i++) {
if (!found_start) {
if (is_white(cmdline[i]))
(*start)++;
else
found_start = true;
} else {
if (is_white(cmdline[i]))
break;
}
}
*end = i - 1;
return found_start;
}
/** List supported commands.
*
* @param argv Argument vector.
*
* @return 0 on failure, 1 on success.
*/
int cmd_help(cmd_arg_t *argv)
{
link_t *cur;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&cmd_lock);
for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {
cmd_info_t *hlp;
hlp = list_get_instance(cur, cmd_info_t, link);
spinlock_lock(&hlp->lock);
printf("%s - %s\n", hlp
->name
, hlp
->description
);
spinlock_unlock(&hlp->lock);
}
spinlock_unlock(&cmd_lock);
interrupts_restore(ipl);
return 1;
}
/** Describe specified command.
*
* @param argv Argument vector.
*
* @return 0 on failure, 1 on success.
*/
int cmd_desc(cmd_arg_t *argv)
{
link_t *cur;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&cmd_lock);
for (cur = cmd_head.next; cur != &cmd_head; cur = cur->next) {
cmd_info_t *hlp;
hlp = list_get_instance(cur, cmd_info_t, link);
spinlock_lock(&hlp->lock);
if (strncmp(hlp
->name
, (const char *) argv
->buffer
, strlen(hlp
->name
)) == 0) { printf("%s - %s\n", hlp
->name
, hlp
->description
); if (hlp->help)
hlp->help();
spinlock_unlock(&hlp->lock);
break;
}
spinlock_unlock(&hlp->lock);
}
spinlock_unlock(&cmd_lock);
interrupts_restore(ipl);
return 1;
}
/** Print detailed description of 'describe' command. */
void desc_help(void)
{
printf("Syntax: describe command_name\n"); }
/** Halt the kernel.
*
* @param argv Argument vector (ignored).
*
* @return 0 on failure, 1 on success (never returns).
*/
int cmd_halt(cmd_arg_t *argv)
{
halt();
return 1;
}