diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | kernel/printk.c | 16 |
2 files changed, 21 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e9261e938f6a..c357a31411cd 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -872,6 +872,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. If specified, z/VM IUCV HVC accepts connections from listed z/VM user IDs only. + keep_bootcon [KNL] + Do not unregister boot console at start. This is only + useful for debugging when something happens in the window + between unregistering the boot console and initializing + the real console. + i2c_bus= [HW] Override the default board specific I2C bus speed or register an additional I2C bus that is not registered from board initialization code. diff --git a/kernel/printk.c b/kernel/printk.c index 33284adb2189..2b591f252e55 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1316,6 +1316,18 @@ void console_start(struct console *console) } EXPORT_SYMBOL(console_start); +static int __read_mostly keep_bootcon; + +static int __init keep_bootcon_setup(char *str) +{ + keep_bootcon = 1; + printk(KERN_INFO "debug: skip boot console de-registration.\n"); + + return 0; +} + +early_param("keep_bootcon", keep_bootcon_setup); + /* * The console driver calls this routine during kernel initialization * to register the console printing procedure with printk() and to @@ -1463,7 +1475,9 @@ void register_console(struct console *newcon) * users know there might be something in the kernel's log buffer that * went to the bootconsole (that they do not see on the real console) */ - if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) { + if (bcon && + ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV) && + !keep_bootcon) { /* we need to iterate through twice, to make sure we print * everything out, before we unregister the console(s) */ |