RISC-V: Update Kconfig to better handle CMDLINE

Added a menu to choose how the built-in command line will be
used and CMDLINE_EXTEND for compatibility with FDT code.

v2: Improved help messages, removed references to bootloader
and made them more descriptive. I also asked help from a
friend who's a language expert just in case.

v3: This time used the corrected text

v4: Copy the config strings from the arm32 port.

v5: Actually copy the config strings from the arm32 port.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Debbie Maliotaki <dmaliotaki@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

1 files changed, 33 insertions, 24 deletions

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 55da93f4e818..23ac6d6f9ab2 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -227,39 +227,48 @@ endmenu
 
 menu "Boot options"
 
-config CMDLINE_BOOL
-        bool "Built-in kernel command line"
+config CMDLINE
+        string "Built-in kernel command line"
         help
-          For most platforms, it is firmware or second stage bootloader
-          that by default specifies the kernel command line options.
-          However, it might be necessary or advantageous to either override
-          the default kernel command line or add a few extra options to it.
-          For such cases, this option allows hardcoding command line options
-          directly into the kernel.
+          For most platforms, the arguments for the kernel's command line
+          are provided at run-time, during boot. However, there are cases
+          where either no arguments are being provided or the provided
+          arguments are insufficient or even invalid.
 
-          For that, choose 'Y' here and fill in the extra boot parameters
-          in CONFIG_CMDLINE.
+          When that occurs, it is possible to define a built-in command
+          line here and choose how the kernel should use it later on.
 
-          The built-in options will be concatenated to the default command
-          line if CMDLINE_FORCE is set to 'N'. Otherwise, the default
-          command line will be ignored and replaced by the built-in string.
+choice
+        prompt "Built-in command line usage" if CMDLINE != ""
+        default CMDLINE_FALLBACK
+        help
+          Choose how the kernel will handle the provided built-in command
+          line.
 
-config CMDLINE
-        string "Built-in kernel command string"
-        depends on CMDLINE_BOOL
-        default ""
+config CMDLINE_FALLBACK
+        bool "Use bootloader kernel arguments if available"
         help
-          Supply command-line options at build time by entering them here.
+          Use the built-in command line as fallback in case we get nothing
+          during boot. This is the default behaviour.
+
+config CMDLINE_EXTEND
+        bool "Extend bootloader kernel arguments"
+        help
+          The command-line arguments provided during boot will be
+          appended to the built-in command line. This is useful in
+          cases where the provided arguments are insufficient and
+          you don't want to or cannot modify them.
+
 
 config CMDLINE_FORCE
-        bool "Built-in command line overrides bootloader arguments"
-        depends on CMDLINE_BOOL
+        bool "Always use the default kernel command string"
         help
-          Set this option to 'Y' to have the kernel ignore the bootloader
-          or firmware command line.  Instead, the built-in command line
-          will be used exclusively.
+          Always use the built-in command line, even if we get one during
+          boot. This is useful in case you need to override the provided
+          command line on systems where you don't have or want control
+          over it.
 
-          If you don't know what to do here, say N.
+endchoice
 
 endmenu