| 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); |
| 141 | |
