bootargs

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arch/arm/kernel/setup.c

void __init setup_arch(char **cmdline_p)

{

strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);

*cmdline_p = cmd_line;

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init/main.c

asmlinkage void __init start_kernel(void)

{

setup_arch(&command_line);

mm_init_owner(&init_mm, &init_task);

mm_init_cpumask(&init_mm);

setup_command_line(command_line);

setup_nr_cpu_ids();

setup_per_cpu_areas();

smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */

build_all_zonelists(NULL);

page_alloc_init();

printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);

parse_early_param();

parse_args("Booting kernel", static_command_line, __start___param,

  __stop___param - __start___param,

  -1, -1, &unknown_bootoption);

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/*

 * We need to store the untouched command line for future reference.

 * We also need to store the touched command line since the parameter

 * parsing is performed in place, and we should allow a component to

 * store reference of name/value for future reference.

 */

static void __init setup_command_line(char *command_line)

{

saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);

static_command_line = alloc_bootmem(strlen (command_line)+1);

strcpy (saved_command_line, boot_command_line);

strcpy (static_command_line, command_line);

}

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/*

 * Unknown boot options get handed to init, unless they look like

 * unused parameters (modprobe will find them in /proc/cmdline).

 */

static int __init unknown_bootoption(char *param, char *val)

{

repair_env_string(param, val);

        printk("HHHHHHHO :%s:%s\n",param,val);

/* Handle obsolete-style parameters */

if (obsolete_checksetup(param))

return 0;

/* Unused module parameter. */

if (strchr(param, '.') && (!val || strchr(param, '.') < val))

return 0;

if (panic_later)

return 0;

if (val) {

/* Environment option */

unsigned int i;

for (i = 0; envp_init[i]; i++) {

if (i == MAX_INIT_ENVS) {

panic_later = "Too many boot env vars at `%s'";

panic_param = param;

}

if (!strncmp(param, envp_init[i], val - param))

break;

}

envp_init[i] = param;

} else {

/* Command line option */

unsigned int i;

for (i = 0; argv_init[i]; i++) {

if (i == MAX_INIT_ARGS) {

panic_later = "Too many boot init vars at `%s'";

panic_param = param;

}

}

argv_init[i] = param;

}

return 0;

}

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static void run_init_process(const char *init_filename)

{

argv_init[0] = init_filename;

kernel_execve(init_filename, argv_init, envp_init);

}

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arch/arm/kernel/sys_arm.c

int kernel_execve(const char *filename,

 const char *const argv[],

 const char *const envp[])

{

struct pt_regs regs;

int ret;

memset(&regs, 0, sizeof(struct pt_regs));

ret = do_execve(filename,

(const char __user *const __user *)argv,

(const char __user *const __user *)envp, &regs);

if (ret < 0)

goto out;

/*

* Save argc to the register structure for userspace.

*/

regs.ARM_r0 = ret;

/*

* We were successful.  We won't be returning to our caller, but

* instead to user space by manipulating the kernel stack.

*/

asm( "add r0, %0, %1\n\t"

"mov r1, %2\n\t"

"mov r2, %3\n\t"

"bl memmove\n\t" /* copy regs to top of stack */

"mov r8, #0\n\t" /* not a syscall */

"mov r9, %0\n\t" /* thread structure */

"mov sp, r0\n\t" /* reposition stack pointer */

"b ret_to_user"

:

: "r" (current_thread_info()),

 "Ir" (THREAD_START_SP - sizeof(regs)),

 "r" (&regs),

 "Ir" (sizeof(regs))

: "r0", "r1", "r2", "r3", "r8", "r9", "ip", "lr", "memory");

 out:

return ret;

}

EXPORT_SYMBOL(kernel_execve);

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