d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make sure the baudrate specified with the BR tag is somewhat sane.

Browse Source 
A baudrate we consider insane is silently replaced with 0. When the
baudrate is 0, we will not try to program the hardware. Instead we
leave the communication speed unaltered, maximizing the chance to
have a working console. Obviously this means we allow specifying a
0 baudrate for exactly that purpose.
This commit is contained in:
Marcel Moolenaar 2004-11-14 21:38:22 +00:00
parent 443ceb1c7e
commit ecf4dc2505
1 changed files with 20 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/dev/uart/uart_subr.c
View File

@ -242,6 +242,26 @@ uart_getenv(int devtype, struct uart_devinfo *di)
*/
if (addr == ~0U)
return (EINVAL);
/*
* Accept only the well-known baudrates. Any invalid baudrate
* is silently replaced with a 0-valued baudrate. The 0 baudrate
* has special meaning. It means that we're not supposed to
* program the baudrate and simply communicate with whatever
* speed the hardware is currently programmed for.
*/
if (di->baudrate >= 19200) {
if (di->baudrate % 19200)
di->baudrate = 0;
} else if (di->baudrate >= 1200) {
if (di->baudrate % 1200)
di->baudrate = 0;
} else if (di->baudrate > 0) {
if (di->baudrate % 75)
di->baudrate = 0;
} else
di->baudrate = 0;
/* XXX the size of the mapping depends on the UART class. */
if (bus_space_map(di->bas.bst, addr, 8, 0, &di->bas.bsh) != 0)
return (EINVAL);