Le 03/03/2021 à 18:57, Will Deacon a écrit :
On Tue, Mar 02, 2021 at 05:25:22PM +0000, Christophe Leroy wrote:
Most architectures have similar boot command line manipulation
options. This patchs adds the definition in init/Kconfig, gated by
CONFIG_HAVE_CMDLINE that the architectures can select to use them.
In order to use this, a few architectures will have to change their
CONFIG options:
- riscv has to replace CMDLINE_FALLBACK by CMDLINE_FROM_BOOTLOADER
- architectures using CONFIG_CMDLINE_OVERRIDE or
CONFIG_CMDLINE_OVERWRITE have to replace them by CONFIG_CMDLINE_FORCE.
Architectures also have to define CONFIG_DEFAULT_CMDLINE.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
init/Kconfig | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/init/Kconfig b/init/Kconfig
index 22946fe5ded9..a0f2ad9467df 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -117,6 +117,62 @@ config INIT_ENV_ARG_LIMIT
Maximum of each of the number of arguments and environment
variables passed to init from the kernel command line.
+config HAVE_CMDLINE
+ bool
+
+config CMDLINE_BOOL
+ bool "Default bootloader kernel arguments"
+ depends on HAVE_CMDLINE
+ help
+ On some platforms, there is currently no way for the boot loader to
+ pass arguments to the kernel. For these platforms, you can supply
+ some command-line options at build time by entering them here. In
+ most cases you will need to specify the root device here.
Why is this needed as well as CMDLINE_FROM_BOOTLOADER? IIUC, the latter
will use CONFIG_CMDLINE if it fails to get anything from the bootloader,
which sounds like the same scenario.
+config CMDLINE
+ string "Initial kernel command string"
s/Initial/Default
which is then consistent with the rest of the text here.
+ depends on CMDLINE_BOOL
Ah, so this is a bit different and I don't think lines-up with the
CMDLINE_BOOL help text.
You are right, the help text is duplicated, I will change the text for the CMDLINE_BOOL
+ default DEFAULT_CMDLINE
+ help
+ On some platforms, there is currently no way for the boot loader to
+ pass arguments to the kernel. For these platforms, you can supply
+ some command-line options at build time by entering them here. In
+ most cases you will need to specify the root device here.
(same stale text)
+choice
+ prompt "Kernel command line type" if CMDLINE != ""
+ default CMDLINE_FROM_BOOTLOADER
+ help
+ Selects the way you want to use the default kernel arguments.
How about:
"Determines how the default kernel arguments are combined with any
arguments passed by the bootloader"
+config CMDLINE_FROM_BOOTLOADER
+ bool "Use bootloader kernel arguments if available"
+ help
+ Uses the command-line options passed by the boot loader. If
+ the boot loader doesn't provide any, the default kernel command
+ string provided in CMDLINE will be used.
+
+config CMDLINE_EXTEND
Can we rename this to CMDLINE_APPEND, please? There is code in the tree
which disagrees about what CMDLINE_EXTEND means, so that will need be
to be updated to be consistent (e.g. the EFI stub parsing order). Having
the generic option with a different name means we won't accidentally end
up with the same inconsistent behaviours.
+ bool "Extend bootloader kernel arguments"
"Append to the bootloader kernel arguments"
+ help
+ The default kernel command string will be appended to the
+ command-line arguments provided during boot.
s/provided during boot/provided by the bootloader/
+
+config CMDLINE_PREPEND
+ bool "Prepend bootloader kernel arguments"
"Prepend to the bootloader kernel arguments"
+ help
+ The default kernel command string will be prepend to the
+ command-line arguments provided during boot.
s/prepend/prepended/
s/provided during boot/provided by the bootloader/
+
+config CMDLINE_FORCE
+ bool "Always use the default kernel command string"
+ help
+ Always use the default kernel command string, even if the boot
+ loader passes other arguments to the kernel.
+ This is useful if you cannot or don't want to change the
+ command-line options your boot loader passes to the kernel.
I find the "This is useful if ..." sentence really confusing, perhaps just
remove it? I'd then tweak it to be:
"Always use the default kernel command string, ignoring any arguments
provided by the bootloader."
Taken all your suggested text.
Thanks
Christophe
