Re: [PATCH] KGDB: refactor kconfig menu

From: Jason Wessel
Date: Sun Jan 27 2008 - 13:01:29 EST

Jan Kiszka wrote:
> This is an attempt to improve the so far, well, unfortunate Kconfig menu
> organization of KGDB. Most notably, it pushes all sub-entries into their
> own menuconfig, removes the (IMHO) unneeded "Method for KGDB
> communication" choice, and ensures everything is indented properly. This
> should keep the original semantic while reducing the number of knobs the
> user is confronted with.
>
>

While it is probably reasonable to put the kgdb options into a sub
entry, you cannot get rid of the "Method for KGDB communication"
choice, unless you re-implement it another way.

It is designed to implement the following:
1) You can chose to build 1 and only 1 KGDB I/O module into the kernel
2) Or you select modules only and can you can build as many additional
KGDB I/O modules as you like.
3) Additional I/O modules can be built and you can load one at run time
if you want to use another I/O method vs #1

KGDB's Kconfig options are designed to allow you to have alternate ways
to select static or run time configuration of the I/O connection to the
KGDB core, IE: over serial, over ethernet, over USB or what ever module
you would like to implement.

Jason.



> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxx>
>
> ---
> lib/Kconfig.kgdb | 91 +++++++++++++++----------------------------------------
> 1 file changed, 25 insertions(+), 66 deletions(-)
>
> Index: b/lib/Kconfig.kgdb
> ===================================================================
> --- a/lib/Kconfig.kgdb
> +++ b/lib/Kconfig.kgdb
> @@ -1,19 +1,9 @@
>
> -config WANT_EXTRA_DEBUG_INFORMATION
> - bool
> - select DEBUG_INFO
> - select UNWIND_INFO
> - select FRAME_POINTER if X86
> - default n
> -
> -config UNWIND_INFO
> - bool
> - default n
> -
> -config KGDB
> +menuconfig KGDB
> bool "KGDB: kernel debugging with remote gdb"
> - select WANT_EXTRA_DEBUG_INFORMATION
> select KGDB_ARCH_HAS_SHADOW_INFO if X86_64
> + select DEBUG_INFO
> + select FRAME_POINTER
> depends on DEBUG_KERNEL && (X86)
> help
> If you say Y here, it will be possible to remotely debug the
> @@ -23,62 +13,20 @@ config KGDB
>
> config KGDB_ARCH_HAS_SHADOW_INFO
> bool
> -
> -config KGDB_CONSOLE
> - bool "KGDB: Console messages through gdb"
> - depends on KGDB
> - help
> - If you say Y here, console messages will appear through gdb.
> - Other consoles such as tty or ttyS will continue to work as usual.
> - Note that if you use this in conjunction with KGDBOE, if the
> - ethernet driver runs into an error condition during use with KGDB,
> - it is possible to hit an infinite recursion, causing the kernel
> - to crash, and typically reboot. For this reason, it is preferable
> - to use NETCONSOLE in conjunction with KGDBOE instead of
> - KGDB_CONSOLE.
> -
> -choice
> - prompt "Method for KGDB communication"
> depends on KGDB
> - default KGDB_8250_NOMODULE
> - help
> - There are a number of different ways in which you can communicate
> - with KGDB. The most common is via serial, with the 8250 driver
> - (should your hardware have an 8250, or ns1655x style uart).
> - Another option is to use the NETPOLL framework and UDP, should
> - your ethernet card support this. Other options may exist.
> - You can elect to have one core I/O driver that is built into the
> - kernel for debugging as the kernel is booting, or using only
> - kernel modules.
> -
> -config KGDB_ONLY_MODULES
> - bool "KGDB: Use only kernel modules for I/O"
> - depends on MODULES
> - help
> - Use only kernel modules to configure KGDB I/O after the
> - kernel is booted.
> -
> -config KGDB_8250_NOMODULE
> - bool "KGDB: On generic serial port (8250)"
> - select KGDB_8250
> - select SERIAL_8250
> - help
> - Uses generic serial port (8250) to communicate with the host
> - GDB. This is independent of the normal (SERIAL_8250) driver
> - for this chipset.
> -endchoice
>
> config KGDB_8250
> - tristate "KGDB: On generic serial port (8250)" if !KGDB_8250_NOMODULE
> - depends on m && KGDB_ONLY_MODULES
> + tristate "KGDB: On generic serial port (8250)"
> + depends on KGDB
> + default y
> help
> Uses generic serial port (8250) to communicate with the host
> GDB. This is independent of the normal (SERIAL_8250) driver
> for this chipset.
>
> config KGDB_SIMPLE_SERIAL
> - bool "Simple selection of KGDB serial port"
> - depends on KGDB_8250_NOMODULE
> + bool "Simple configuration of KGDB serial port"
> + depends on (KGDB_8250 = y)
> default y
> help
> If you say Y here, you will only have to pick the baud rate
> @@ -90,7 +38,7 @@ config KGDB_SIMPLE_SERIAL
>
> config KGDB_BAUDRATE
> int "Debug serial port baud rate"
> - depends on (KGDB_8250 && KGDB_SIMPLE_SERIAL)
> + depends on KGDB_SIMPLE_SERIAL
> default "115200"
> help
> gdb and the kernel stub need to agree on the baud rate to be
> @@ -99,16 +47,15 @@ config KGDB_BAUDRATE
>
> config KGDB_PORT_NUM
> int "Serial port number for KGDB"
> - range 0 1 if KGDB_MPSC
> range 0 3
> - depends on (KGDB_8250 && KGDB_SIMPLE_SERIAL) || KGDB_MPSC
> + depends on KGDB_SIMPLE_SERIAL
> default "1"
> help
> Pick the port number (0 based) for KGDB to use.
>
> config KGDB_8250_CONF_STRING
> string "Configuration string for KGDB"
> - depends on KGDB_8250_NOMODULE && !KGDB_SIMPLE_SERIAL
> + depends on KGDB_8250 && !KGDB_SIMPLE_SERIAL
> default "io,2f8,115200,3" if X86
> help
> The format of this string should be <io or mmio>,
> @@ -119,11 +66,23 @@ config KGDB_8250_CONF_STRING
> config KGDB_ATTACH_WAIT
> bool "KGDB: Wait for debugger to attach on an unknown exception"
> depends on KGDB
> - default y if KGDB_8250_NOMODULE
> - default n if !KGDB_8250_NOMODULE
> + default (KGDB_8250 = y)
> help
> If a panic occurs, or any kind of exception, the kgdb will
> stop and wait for a debugger to attach. This sets the
> default behavior for waiting for the debugger to attach. This
> value can also be changed at runtime through
> /sys/module/kgdb/parameters/attachwait
> +
> +config KGDB_CONSOLE
> + bool "KGDB: Console messages through gdb"
> + depends on KGDB
> + help
> + If you say Y here, console messages will appear through gdb.
> + Other consoles such as tty or ttyS will continue to work as usual.
> + Note that if you use this in conjunction with KGDBOE, if the
> + ethernet driver runs into an error condition during use with KGDB,
> + it is possible to hit an infinite recursion, causing the kernel
> + to crash, and typically reboot. For this reason, it is preferable
> + to use NETCONSOLE in conjunction with KGDBOE instead of
> + KGDB_CONSOLE.
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/