It's possible that an architecture may want to populate boot_command_line before calling the device tree code. Currently, early_init_dt_scan_chosen won't accept a NULL in the data parameter and it returns immediately if you send one. I changed early_init_dt_scan_nodes() to send a NULL into early_init_dt_scan_chosen() , then I made early_init_dt_scan_chosen() to do the initrd checking, and the rng-seed checking and skip all the command line related code. Given lots of changes to the command line, I think it makes sense to allow the initrd code and rng-seed code to be run without forcing the command line handling. I'm also submitting changes to arm64 which populate boot_command_line much early and this device tree code overwrites boot_command_line in that case. This code depends on all architecture to have a NULL boot_command_line at boot up when this function runs, unless it's already populated. This code was boot tested on powerpc 32bit, x86, and arm64. Cc: xe-linux-external@xxxxxxxxx Signed-off-by: Daniel Walker <danielwa@xxxxxxxxx> --- drivers/of/fdt.c | 44 +++++++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 19 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index adb26aff481d..a1fda952ce60 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1052,36 +1052,38 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); - if (depth != 1 || !data || - (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) + if (depth != 1 || (strcmp(uname, "chosen") != 0 + && strcmp(uname, "chosen@0") != 0)) return 0; early_init_dt_check_for_initrd(node); - /* Retrieve command line */ - p = of_get_flat_dt_prop(node, "bootargs", &l); - if (p != NULL && l > 0) - strlcpy(data, p, min(l, COMMAND_LINE_SIZE)); + if (data) { + /* Retrieve command line */ + p = of_get_flat_dt_prop(node, "bootargs", &l); + if (p != NULL && l > 0) + strlcpy(data, p, min(l, COMMAND_LINE_SIZE)); - /* - * CONFIG_CMDLINE is meant to be a default in case nothing else - * managed to set the command line, unless CONFIG_CMDLINE_FORCE - * is set in which case we override whatever was found earlier. - */ + /* + * CONFIG_CMDLINE is meant to be a default in case nothing else + * managed to set the command line, unless CONFIG_CMDLINE_FORCE + * is set in which case we override whatever was found earlier. + */ #ifdef CONFIG_CMDLINE #if defined(CONFIG_CMDLINE_EXTEND) - strlcat(data, " ", COMMAND_LINE_SIZE); - strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); + strlcat(data, " ", COMMAND_LINE_SIZE); + strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #elif defined(CONFIG_CMDLINE_FORCE) - strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); -#else - /* No arguments from boot loader, use kernel's cmdl*/ - if (!((char *)data)[0]) strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#else + /* No arguments from boot loader, use kernel's cmdl*/ + if (!((char *)data)[0]) + strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #endif #endif /* CONFIG_CMDLINE */ - pr_debug("Command line is: %s\n", (char *)data); + pr_debug("Command line is: %s\n", (char *)data); + } rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); if (rng_seed && l > 0) { @@ -1202,7 +1204,11 @@ void __init early_init_dt_scan_nodes(void) int rc = 0; /* Retrieve various information from the /chosen node */ - rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); + if (boot_command_line[0]) + rc = of_scan_flat_dt(early_init_dt_scan_chosen, NULL); + else + rc = of_scan_flat_dt(early_init_dt_scan_chosen, + boot_command_line); if (!rc) pr_warn("No chosen node found, continuing without\n"); -- 2.25.1