[PATCH RESEND v5 0/2] x86/earlyprintk: setup earlyprintk as early as possible

From: Alexander Kuleshov
Date: Mon May 11 2015 - 06:08:54 EST

The early_printk function is usable after setup_early_printk will be executed. We
pass 'earlyprintk' through the kernel command line. It means that earlyprintk
will be usable only after the 'parse_early_param' will be executed. So we have
usable earlyprintk only during early boot, kernel decompression and after call
of the 'parse_early_param'. This patchset makes earlyprintk usable before the
call of the 'parse_early_param'.

These patchset provides two patches:

1. Move handling of the builtin command line to the separate function
from the setup_arch. Now we can call it from the arch/x86/kernel/head{32,64}.c,
and find 'earlyprintk' kernel command line paramter there.

2. Provide setup_serial_console function to setup serial earlyprintk in the

Changes v5:

* Call setup_builtin_cmdline instead of setup_cmdline

Changes v4:

* Move setup_early_serial_console from the include/linux/printk.h
to the arch/x86/include/asm/serial.h, because this function is only
for x86 now.

Changes v3:

* Call setup_cmdline before setup_early_printk;
* setup_early_printk call wrapped with the setup_early_serial_console which
checks that 'serial' given to the earlyprintk command line option. This
prevents call of the setup_early_printk with the given pciserial/dbgp/efi,
because they are using early_ioremap.

Changes v2:

* Comment added before the setup_early_printk call;
* Added information about testing to the commit message.

Alexander Kuleshov (2):
x86/setup: update boot_command_line with builtin_cmdline in separate
x86/earlyprintk: setup earlyprintk as early as possible

arch/x86/include/asm/serial.h | 2 ++
arch/x86/include/asm/setup.h | 3 ++-
arch/x86/kernel/early_printk.c | 25 +++++++++++++++++++++++++
arch/x86/kernel/head32.c | 6 ++++++
arch/x86/kernel/head64.c | 7 +++++++
arch/x86/kernel/setup.c | 28 +++++++++++++++-------------
6 files changed, 57 insertions(+), 14 deletions(-)


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