path: root/init
diff options
authorYinghai Lu <Yinghai.Lu@Sun.COM>2007-07-15 23:37:59 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:35 -0700
commit18a8bd949d6adb311ea816125ff65050df1f3f6e (patch)
tree4365db908430747a5c08cacdb4354577b7bfead7 /init
parentb1c931e39327ef121797927d4b3198d370e75b9b (diff)
serial: convert early_uart to earlycon for 8250
Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in serial initializing stage. the console_init=>serial8250_console_init=> register_console=>serial8250_console_setup will return -ENDEV, and console ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in drivers/serial/serial_core.c to call register_console to get console ttyS0. that is too late. Make early_uart to use early_param, so uart console can be used earlier. Make it to be bootconsole with CON_BOOT flag, so can use console handover feature. and it will switch to corresponding normal serial console automatically. new command line will be: console=uart8250,io,0x3f8,9600n8 console=uart8250,mmio,0xff5e0000,115200n8 or earlycon=uart8250,io,0x3f8,9600n8 earlycon=uart8250,mmio,0xff5e0000,115200n8 it will print in very early stage: Early serial console at I/O port 0x3f8 (options '9600n8') console [uart0] enabled later for console it will print: console handover: boot [uart0] -> real [ttyS0] Signed-off-by: <yinghai.lu@sun.com> Cc: Andi Kleen <ak@suse.de> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
1 files changed, 4 insertions, 1 deletions
diff --git a/init/main.c b/init/main.c
index 0eb1c7463fe..038c7cb5239 100644
--- a/init/main.c
+++ b/init/main.c
@@ -453,7 +453,10 @@ static int __init do_early_param(char *param, char *val)
struct obs_kernel_param *p;
for (p = __setup_start; p < __setup_end; p++) {
- if (p->early && strcmp(param, p->str) == 0) {
+ if ((p->early && strcmp(param, p->str) == 0) ||
+ (strcmp(param, "console") == 0 &&
+ strcmp(p->str, "earlycon") == 0)
+ ) {
if (p->setup_func(val) != 0)
"Malformed early option '%s'\n", param);