minix/drivers/log/diag.c
David van Moolenbroek f56c4001d5 TTY/LOG driver cleanup:
- remove non-safecopy support from TTY
- make TTY warning-free with gcc -Wall
- remove obsolete diagnostics support
2011-03-25 10:43:24 +00:00

56 lines
2 KiB
C

/* This file handle diagnostic output that is sent to the LOG driver. Output
* can be either from the kernel, or from other system processes. Output from
* system processes is also routed through the kernel. The kernel notifies
* this driver with a SIGKMESS signal if any messages are available.
*
* Changes:
* 21 July 2005: Created (Jorrit N. Herder)
*/
#include "log.h"
/*==========================================================================*
* do_new_kmess *
*==========================================================================*/
PUBLIC void do_new_kmess(void)
{
/* Notification for a new kernel message. */
static struct kmessages kmess; /* entire kmess structure */
static char print_buf[_KMESS_BUF_SIZE]; /* copy new message here */
int bytes;
int i, r;
static int prev_next = 0;
/* Try to get a fresh copy of the buffer with kernel messages. */
if ((r=sys_getkmessages(&kmess)) != OK) {
printf("log: couldn't get copy of kmessages: %d\n", r);
return;
}
/* Print only the new part. Determine how many new bytes there are with
* help of the current and previous 'next' index. Note that the kernel
* buffer is circular. This works fine if less than KMESS_BUF_SIZE bytes
* are new data; else we miss % KMESS_BUF_SIZE here.
* Check for size being positive, the buffer might as well be emptied!
*/
if (kmess.km_size > 0) {
bytes = ((kmess.km_next + _KMESS_BUF_SIZE) - prev_next) %
_KMESS_BUF_SIZE;
r= prev_next; /* start at previous old */
i=0;
while (bytes > 0) {
print_buf[i] = kmess.km_buf[(r%_KMESS_BUF_SIZE)];
bytes --;
r ++;
i ++;
}
/* Now terminate the new message and save it in the log. */
print_buf[i] = 0;
log_append(print_buf, i);
}
/* Almost done, store 'next' so that we can determine what part of the
* kernel messages buffer to print next time a notification arrives.
*/
prev_next = kmess.km_next;
}