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Diffstat (limited to 'sys/dev')
-rw-r--r--sys/dev/cons/cons.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/sys/dev/cons/cons.c b/sys/dev/cons/cons.c
index 2cef071..9921ff8 100644
--- a/sys/dev/cons/cons.c
+++ b/sys/dev/cons/cons.c
@@ -343,6 +343,7 @@ cons_fast_putch(struct cons_screen *scr, char c)
static int
dev_write(dev_t dev, struct sio_txn *sio, int flags)
{
+ cons_attach();
cons_putstr(&g_root_scr, sio->buf, sio->len);
cons_flush(&g_root_scr);
return sio->len;
@@ -372,6 +373,7 @@ dev_read(dev_t dev, struct sio_txn *sio, int flags)
return -EAGAIN;
}
+ cons_attach();
spinlock_acquire(&g_root_scr.lock);
for (;;) {
/* Buffer too small */
@@ -468,6 +470,69 @@ ctl_feat_write(struct ctlfs_dev *cdp, struct sio_txn *sio)
}
/*
+ * Detach the currently running process from the
+ * console.
+ */
+int
+cons_detach(void)
+{
+ struct cons_screen *scr;
+
+ scr = &g_root_scr;
+ if (scr->atproc == NULL) {
+ return 0;
+ }
+ if (scr->atproc_lock == NULL) {
+ return 0;
+ }
+
+ scr = &g_root_scr;
+ scr->atproc = NULL;
+ mutex_release(scr->atproc_lock);
+ return 0;
+}
+
+/*
+ * Attach the current process to the
+ * console.
+ */
+int
+cons_attach(void)
+{
+ struct cons_screen *scr;
+ struct proc *td, *atproc;
+
+ td = this_td();
+ if (td == NULL) {
+ return -1;
+ }
+
+ scr = &g_root_scr;
+ if (scr->atproc_lock == NULL) {
+ return 0;
+ }
+
+ scr = &g_root_scr;
+ atproc = scr->atproc;
+
+ if (atproc != NULL) {
+ if (atproc->pid == td->pid) {
+ return 0;
+ }
+
+ /*
+ * Do not release this here as we want
+ * any other process that tries to attach
+ * to wait.
+ */
+ mutex_acquire(scr->atproc_lock, 0);
+ }
+
+ scr->atproc = td;
+ return 0;
+}
+
+/*
* Reset console color.
*/
void
@@ -556,6 +621,8 @@ cons_init(void)
g_root_scr.nrows = fbdev.height / FONT_HEIGHT;
g_root_scr.ncols = fbdev.width / FONT_WIDTH;
g_root_scr.fbdev = fbdev;
+ g_root_scr.atproc = NULL;
+ g_root_scr.atproc_lock = NULL;
memset(&g_root_scr.lock, 0, sizeof(g_root_scr.lock));
cons_init_bufs(&g_root_scr);
SHOW_CURSOR(&g_root_scr);
@@ -578,6 +645,9 @@ cons_expose(void)
return;
}
+ /* Init the attached proc mutex lock */
+ g_root_scr.atproc_lock = mutex_new("console0");
+
/* Register the device here */
major = dev_alloc_major();
dev = dev_alloc(major);