From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: Paul Mackerras , From: David Gibson Subject: [PATCH 3/4] powerpc: Clean up zImage handling of the command line In-Reply-To: <20070322054812.GA16993@localhost.localdomain> Message-Id: <20070322060221.6B429DDF4D@ozlabs.org> Date: Thu, 22 Mar 2007 17:02:21 +1100 (EST) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch cleans up how the zImage code manipulates the kernel command line. Notable improvements from the old handling: - Command line manipulation is consolidated into a new prep_cmdline() function, rather than being scattered across start() and some helper functions - Less stack space use: we use just a single global command line buffer, which can be initialized by an external tool as before, we no longer need another command line sized buffer on the stack. - Easier to support platforms whose firmware passes a commandline, but not a device tree. Platform code can now point new loader_info fields to the firmware's command line, rather than having to do early manipulation of the /chosen bootargs property which may then be rewritten again by the core. Signed-off-by: David Gibson --- arch/powerpc/boot/main.c | 52 +++++++++++++++++------------------------------ arch/powerpc/boot/ops.h | 2 + 2 files changed, 21 insertions(+), 33 deletions(-) Index: working-2.6/arch/powerpc/boot/main.c =================================================================== --- working-2.6.orig/arch/powerpc/boot/main.c 2007-03-22 13:43:13.000000000 +1100 +++ working-2.6/arch/powerpc/boot/main.c 2007-03-22 13:46:52.000000000 +1100 @@ -204,31 +204,22 @@ static struct addr_range prep_initrd(str * edit the command line passed to vmlinux (by setting /chosen/bootargs). * The buffer is put in it's own section so that tools may locate it easier. */ -static char builtin_cmdline[COMMAND_LINE_SIZE] +static char cmdline[COMMAND_LINE_SIZE] __attribute__((__section__("__builtin_cmdline"))); -static void get_cmdline(char *buf, int size) +static void prep_cmdline(void *chosen) { - void *devp; - int len = strlen(builtin_cmdline); + if (cmdline[0] == '\0') + getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1); - buf[0] = '\0'; + printf("\n\rLinux/PowerPC load: %s", cmdline); + /* If possible, edit the command line */ + if (console_ops.edit_cmdline) + console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE); + printf("\n\r"); - if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */ - len = min(len, size-1); - strncpy(buf, builtin_cmdline, len); - buf[len] = '\0'; - } - else if ((devp = finddevice("/chosen"))) - getprop(devp, "bootargs", buf, size); -} - -static void set_cmdline(char *buf) -{ - void *devp; - - if ((devp = finddevice("/chosen"))) - setprop(devp, "bootargs", buf, strlen(buf) + 1); + /* Put the command line back into the devtree for the kernel */ + setprop_str(chosen, "bootargs", cmdline); } struct platform_ops platform_ops; @@ -240,10 +231,16 @@ void start(void *sp) { struct addr_range vmlinux, initrd; kernel_entry_t kentry; - char cmdline[COMMAND_LINE_SIZE]; unsigned long ft_addr = 0; void *chosen; + /* Do this first, because malloc() could clobber the loader's + * command line. Only use the loader command line if a + * built-in command line wasn't set by an external tool */ + if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0')) + memmove(cmdline, loader_info.cmdline, + min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1)); + if (console_ops.open && (console_ops.open() < 0)) exit(); if (platform_ops.fixups) @@ -260,18 +257,7 @@ void start(void *sp) vmlinux = prep_kernel(); initrd = prep_initrd(vmlinux, chosen, loader_info.initrd_addr, loader_info.initrd_size); - - /* If cmdline came from zimage wrapper or if we can edit the one - * in the dt, print it out and edit it, if possible. - */ - if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) { - get_cmdline(cmdline, COMMAND_LINE_SIZE); - printf("\n\rLinux/PowerPC load: %s", cmdline); - if (console_ops.edit_cmdline) - console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE); - printf("\n\r"); - set_cmdline(cmdline); - } + prep_cmdline(chosen); printf("Finalizing device tree..."); if (dt_ops.finalize) Index: working-2.6/arch/powerpc/boot/ops.h =================================================================== --- working-2.6.orig/arch/powerpc/boot/ops.h 2007-03-22 13:43:13.000000000 +1100 +++ working-2.6/arch/powerpc/boot/ops.h 2007-03-22 13:45:26.000000000 +1100 @@ -70,6 +70,8 @@ struct serial_console_data { struct loader_info { void *promptr; unsigned long initrd_addr, initrd_size; + char *cmdline; + int cmdline_len; }; extern struct loader_info loader_info;