Messages in this thread Patch in this message | | | Date | Wed, 27 Feb 2008 13:18:57 -0500 | From | Bill Nottingham <> | Subject | [PATCH, RFC, BAD IDEA] /proc/tty/console |
| |
I'm not seriously proposing this. But, as far as I can tell, this information isn't exposed to userspace anywhere, and it's a useful thing to know. I'm certainly open for better ideas on how to expose this (sysfs attributes? other?)
....
The attached patch adds /proc/tty/console. The contents of it are simply a description of the current drivers attached to /dev/console. For example, a boot with 'console=ttyS3,115200n1 console=tty0' would yield:
# cat /proc/tty/console unknown /dev/tty0 serial /dev/ttyS3
Bill
--- diff -ru linux-2.6.24.noarch/fs/proc/proc_tty.c linux/fs/proc/proc_tty.c --- linux-2.6.24.noarch/fs/proc/proc_tty.c 2008-02-27 12:50:59.000000000 -0500 +++ linux/fs/proc/proc_tty.c 2008-02-27 12:25:54.000000000 -0500 @@ -6,6 +6,7 @@ #include <asm/uaccess.h> +#include <linux/console.h> #include <linux/init.h> #include <linux/errno.h> #include <linux/time.h> @@ -129,6 +130,38 @@ return seq_open(file, &tty_drivers_op); } +static int show_tty_console(struct seq_file *m, void *v) +{ + int index; + struct console *c; + + for (c = console_drivers; c ; c = c->next) { + struct tty_driver *t = NULL; + if (!c->device) + continue; + t = c->device(c, &index); + seq_printf(m, "%-20s", t->driver_name ? t->driver_name : "unknown"); + seq_printf(m, "/dev/%s%d", t->name, c->index); + seq_printf(m, "\n"); + } + return 0; +} + +static void *c_start(struct seq_file *m, loff_t *pos) +{ + return *pos == 0 ? &c_start : NULL; +} + +static void *c_next(struct seq_file *m, void *v, loff_t *pos) +{ + ++*pos; + return c_start(m, pos); +} + +static void c_stop(struct seq_file *m, void *v) +{ +} + static const struct file_operations proc_tty_drivers_operations = { .open = tty_drivers_open, .read = seq_read, @@ -136,6 +169,25 @@ .release = seq_release, }; +static const struct seq_operations tty_console_op = { + .start = c_start, + .next = c_next, + .stop = c_stop, + .show = show_tty_console +}; + +static int tty_console_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &tty_console_op); +} + +static const struct file_operations proc_tty_console_operations = { + .open = tty_console_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release +}; + /* * This is the handler for /proc/tty/ldiscs */ @@ -230,4 +282,7 @@ entry = create_proc_entry("tty/drivers", 0, NULL); if (entry) entry->proc_fops = &proc_tty_drivers_operations; + entry = create_proc_entry("tty/console", 0, NULL); + if (entry) + entry->proc_fops = &proc_tty_console_operations; }
| |