target/linux/mcs814x/patches-3.3/010-fdt_config_cmdline_extend.patch

   1 The old logic assumes CMDLINE_FROM_BOOTLOADER vs. CMDLINE_FORCE and
   2 ignores CMDLINE_EXTEND.  Here's the old logic:
   3
   4 - CONFIG_CMDLINE_FORCE=true
   5     CONFIG_CMDLINE
   6 - dt bootargs=non-empty:
   7     dt bootargs
   8 - dt bootargs=empty, @data is non-empty string
   9     @data is left unchanged
  10 - dt bootargs=empty, @data is empty string
  11     CONFIG_CMDLINE (or "" if that's not defined)
  12
  13 The new logic is now documented in of_fdt.h and is copied here for
  14 reference:
  15
  16 - CONFIG_CMDLINE_FORCE=true
  17     CONFIG_CMDLINE
  18 - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
  19     @data + dt bootargs (even if dt bootargs are empty)
  20 - CONFIG_CMDLINE_EXTEND=true, @data is empty string
  21     CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
  22 - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
  23     dt bootargs
  24 - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
  25     @data is left unchanged
  26 - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
  27     CONFIG_CMDLINE (or "" if that's not defined)
  28
  29 Signed-off-by: Doug Anderson <diand...@chromium.org>
  30 CC: devicetree-discuss@lists.ozlabs.org
  31 CC: Grant Likely <grant.lik...@secretlab.ca>
  32 CC: Benjamin Herrenschmidt <b...@kernel.crashing.org>
  33 CC: Rob Herring <rob.herr...@calxeda.com>
  34 ---
  35
  36 --- a/drivers/of/fdt.c
  37 +++ b/drivers/of/fdt.c
  38 @@ -663,6 +663,29 @@ int __init early_init_dt_scan_memory(uns
  39         return 0;
  40  }
  41
  42 +/*
  43 + * Convert configs to something easy to use in C code
  44 + */
  45 +#if defined(CONFIG_CMDLINE_FORCE)
  46 +static const int overwrite_incoming_cmdline = 1;
  47 +static const int read_dt_cmdline;
  48 +static const int concat_cmdline;
  49 +#elif defined(CONFIG_CMDLINE_EXTEND)
  50 +static const int overwrite_incoming_cmdline;
  51 +static const int read_dt_cmdline = 1;
  52 +static const int concat_cmdline = 1;
  53 +#else /* CMDLINE_FROM_BOOTLOADER */
  54 +static const int overwrite_incoming_cmdline;
  55 +static const int read_dt_cmdline = 1;
  56 +static const int concat_cmdline;
  57 +#endif
  58 +
  59 +#ifdef CONFIG_CMDLINE
  60 +static const char *config_cmdline = CONFIG_CMDLINE;
  61 +#else
  62 +static const char *config_cmdline = "";
  63 +#endif
  64 +
  65  int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
  66                                      int depth, void *data)
  67  {
  68 @@ -677,22 +700,26 @@ int __init early_init_dt_scan_chosen(uns
  69
  70         early_init_dt_check_for_initrd(node);
  71
  72 -       /* Retrieve command line */
  73 -       p = of_get_flat_dt_prop(node, "bootargs", &l);
  74 -       if (p != NULL && l > 0)
  75 -               strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
  76 -
  77 -       /*
  78 -        * CONFIG_CMDLINE is meant to be a default in case nothing else
  79 -        * managed to set the command line, unless CONFIG_CMDLINE_FORCE
  80 -        * is set in which case we override whatever was found earlier.
  81 -        */
  82 -#ifdef CONFIG_CMDLINE
  83 -#ifndef CONFIG_CMDLINE_FORCE
  84 -       if (!((char *)data)[0])
  85 -#endif
  86 -               strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
  87 -#endif /* CONFIG_CMDLINE */
  88 +       /* Put CONFIG_CMDLINE in if forced or if data had nothing in it to start */
  89 +       if (overwrite_incoming_cmdline || !((char *)data)[0])
  90 +               strlcpy(data, config_cmdline, COMMAND_LINE_SIZE);
  91 +
  92 +       /* Retrieve command line unless forcing */
  93 +       if (read_dt_cmdline) {
  94 +               p = of_get_flat_dt_prop(node, "bootargs", &l);
  95 +               if (p != NULL && l > 0) {
  96 +                       if (concat_cmdline) {
  97 +                               strlcat(data, " ", COMMAND_LINE_SIZE);
  98 +                               strlcat(data, p, min_t(int, (int)l,
  99 +                                               COMMAND_LINE_SIZE));
 100 +                       } else
 101 +                               strlcpy(data, p, min_t(int, (int)l,
 102 +                                               COMMAND_LINE_SIZE));
 103 +               }
 104 +       }
 105 +
 106 +        pr_debug("Command line is: %s\n", (char*)data);
 107 +
 108
 109         pr_debug("Command line is: %s\n", (char*)data);
 110
 111 --- a/include/linux/of_fdt.h
 112 +++ b/include/linux/of_fdt.h
 113 @@ -91,6 +91,27 @@ extern int of_flat_dt_is_compatible(unsi
 114  extern int of_flat_dt_match(unsigned long node, const char *const *matches);
 115  extern unsigned long of_get_flat_dt_root(void);
 116
 117 +/*
 118 + * early_init_dt_scan_chosen - scan the device tree for ramdisk and bootargs
 119 + *
 120 + * The boot arguments will be placed into the memory pointed to by @data.
 121 + * That memory should be COMMAND_LINE_SIZE big and initialized to be a valid
 122 + * (possibly empty) string.  Logic for what will be in @data after this
 123 + * function finishes:
 124 + *
 125 + * - CONFIG_CMDLINE_FORCE=true
 126 + *     CONFIG_CMDLINE
 127 + * - CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
 128 + *     @data + dt bootargs (even if dt bootargs are empty)
 129 + * - CONFIG_CMDLINE_EXTEND=true, @data is empty string
 130 + *     CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
 131 + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
 132 + *     dt bootargs
 133 + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
 134 + *     @data is left unchanged
 135 + * - CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
 136 + *     CONFIG_CMDLINE (or "" if that's not defined)
 137 + */
 138  extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
 139                                      int depth, void *data);
 140  extern void early_init_dt_check_for_initrd(unsigned long node);