From: mick@ics.forth.gr (Nick Kossifidis) Date: Tue, 2 Oct 2018 17:04:49 +0300 Subject: [PATCH] RISC-V: Implement built-in command line feature Message-ID: <20181002140449.24147-1-mick@ics.forth.gr> To: linux-riscv@lists.infradead.org List-Id: linux-riscv.lists.infradead.org This patch enables the use of a built-in kernel command line, which can optionaly also override the command line provided by the boot loader. Signed-off-by: Nick Kossifidis --- arch/riscv/kernel/setup.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index aee603123..fd171ca7f 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -39,6 +40,14 @@ #include #include +#ifdef CONFIG_CMDLINE_BOOL +#ifdef CONFIG_CMDLINE_FORCE + static const char fixed_cmdline[] __initconst = CONFIG_CMDLINE; +#else + static char builtin_cmdline[] __initdata = CONFIG_CMDLINE; +#endif +#endif + #ifdef CONFIG_EARLY_PRINTK static void sbi_console_write(struct console *co, const char *buf, unsigned int n) @@ -215,6 +224,46 @@ void __init setup_arch(char **cmdline_p) register_console(early_console); } #endif + + /* When we return, cmdline_p should point to a temporary + * buffer on the kernel's init section (that gets cleaned up + * later on) to be saved on static_command_line and parsed for + * parameters. + * + * That string may get tweaked during parameter parsing so we + * also want to keep an untouched version of the command line + * to display on dmesg, /proc/cmdline etc. + * + * At this point boot_command_line is a temporary buffer + * (also on the init section) that contains the command line + * string passed from the boot loader. After we return, + * it will be saved to saved_command_line that holds the + * untouched version of the command line. + * + * Since we won't be doing any parameter parsing here, we'll + * hold the initial/untouched command line string on + * boot_command_line and make cmdline_p point to it as well. + * This way boot_command_line will be copied to both + * saved_command_line and static_command_line. + */ +#ifdef CONFIG_CMDLINE_BOOL +#ifdef CONFIG_CMDLINE_FORCE + /* Built-in args override boot loader args and + * boot loader args are being ignored. + */ + strlcpy(boot_command_line, fixed_cmdline, COMMAND_LINE_SIZE); +#else + /* Boot loader args override built-in args so we + * need to put built-in args before boot loader args. + */ + if (builtin_cmdline[0]) { + strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE); + strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE); + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); + } +#endif +#endif + *cmdline_p = boot_command_line; parse_early_param(); -- 2.16.4