target/linux/generic/patches-3.0/333-mips-kexec-get-kernel-parameters-from-kexec-tools.patch

   1 From 240c76841b26f1b09aaced33414ee1d08b6454cf Mon Sep 17 00:00:00 2001
   2 From: Wu Zhangjin <wuzhangjin@gmail.com>
   3 Date: Sat, 15 Jan 2011 12:46:03 +0000
   4 Subject: MIPS: Get kernel parameters from kexec-tools
   5
   6 Before, we simply use the command lines from the original bootloader,
   7 but it is not convenient. Now, we accept the kernel parameters from the
   8 --command-line or --append option of the kexec-tools.  But If not
   9 --command-line or --apend option indicated, will fall back to use the
  10 ones from the original bootloader.
  11
  12 Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
  13 ---
  14 --- a/arch/mips/kernel/machine_kexec.c
  15 +++ b/arch/mips/kernel/machine_kexec.c
  16 @@ -13,6 +13,7 @@
  17  #include <asm/bootinfo.h>
  18  #include <asm/cacheflush.h>
  19  #include <asm/page.h>
  20 +#include <asm/uaccess.h>
  21
  22  int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  23  void (*_machine_kexec_shutdown)(void) = NULL;
  24 @@ -35,6 +36,56 @@ static void machine_kexec_init_args(void
  25         pr_info("kexec_args[3] (desc): %p\n", (void *)kexec_args[3]);
  26  }
  27
  28 +#define ARGV_MAX_ARGS (COMMAND_LINE_SIZE / 15)
  29 +
  30 +int machine_kexec_pass_args(struct kimage *image)
  31 +{
  32 +       int i, argc = 0;
  33 +       char *bootloader = "kexec";
  34 +       int *kexec_argv = (int *)kexec_args[1];
  35 +
  36 +       for (i = 0; i < image->nr_segments; i++) {
  37 +               if (!strncmp(bootloader, (char *)image->segment[i].buf,
  38 +                               strlen(bootloader))) {
  39 +                       /*
  40 +                        * convert command line string to array
  41 +                        * of parameters (as bootloader does).
  42 +                        */
  43 +                       /*
  44 +                        * Note: we do treat the 1st string "kexec" as an
  45 +                        * argument ;-) so, argc here is 1.
  46 +                        */
  47 +                       char *str = (char *)image->segment[i].buf;
  48 +                       char *ptr = strchr(str, ' ');
  49 +                       char *kbuf = (char *)kexec_argv[0];
  50 +                       /* Whenever --command-line or --append used, "kexec" is copied */
  51 +                       argc = 1;
  52 +                       /* Parse the offset */
  53 +                       while (ptr && (ARGV_MAX_ARGS > argc)) {
  54 +                               *ptr = '\0';
  55 +                               if (ptr[1] != ' ' && ptr[1] != '\0') {
  56 +                                       int offt = (int)(ptr - str + 1);
  57 +                                       kexec_argv[argc] = (int)kbuf + offt;
  58 +                                       argc++;
  59 +                               }
  60 +                               ptr = strchr(ptr + 1, ' ');
  61 +                       }
  62 +                       if (argc > 1) {
  63 +                               /* Copy to kernel space */
  64 +                               copy_from_user(kbuf, (char *)image->segment[i].buf, image->segment[i].bufsz);
  65 +                               fw_arg0 = kexec_args[0] = argc;
  66 +                       }
  67 +                       break;
  68 +               }
  69 +       }
  70 +
  71 +       pr_info("argc = %lu\n", kexec_args[0]);
  72 +       for (i = 0; i < kexec_args[0]; i++)
  73 +               pr_info("argv[%d] = %p, %s\n", i, (char *)kexec_argv[i], (char *)kexec_argv[i]);
  74 +
  75 +       return 0;
  76 +}
  77 +
  78  int
  79  machine_kexec_prepare(struct kimage *kimage)
  80  {
  81 @@ -45,6 +96,7 @@ machine_kexec_prepare(struct kimage *kim
  82          * This can be overrided by _machine_kexec_prepare().
  83          */
  84         machine_kexec_init_args();
  85 +       machine_kexec_pass_args(kimage);
  86
  87         if (_machine_kexec_prepare)
  88                 return _machine_kexec_prepare(kimage);