diff options
Diffstat (limited to 'drivers/of/fdt.c')
| -rw-r--r-- | drivers/of/fdt.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index dfeba8b8ce94..e5a385285149 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -8,6 +8,7 @@ #define pr_fmt(fmt) "OF: fdt: " fmt +#include <linux/acpi.h> #include <linux/crash_dump.h> #include <linux/crc32.h> #include <linux/kernel.h> @@ -33,6 +34,13 @@ #include "of_private.h" /* + * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by + * cmd_dt_S_dtb in scripts/Makefile.lib + */ +extern uint8_t __dtb_empty_root_begin[]; +extern uint8_t __dtb_empty_root_end[]; + +/* * of_fdt_limit_memory - limit the number of regions in the /memory node * @limit: maximum entries * @@ -1343,7 +1351,29 @@ static void *__init copy_device_tree(void *fdt) */ void __init unflatten_device_tree(void) { - __unflatten_device_tree(initial_boot_params, NULL, &of_root, + void *fdt = initial_boot_params; + + /* Don't use the bootloader provided DTB if ACPI is enabled */ + if (!acpi_disabled) + fdt = NULL; + + /* + * Populate an empty root node when ACPI is enabled or bootloader + * doesn't provide one. + */ + if (!fdt) { + fdt = (void *) __dtb_empty_root_begin; + /* fdt_totalsize() will be used for copy size */ + if (fdt_totalsize(fdt) > + __dtb_empty_root_end - __dtb_empty_root_begin) { + pr_err("invalid size in dtb_empty_root\n"); + return; + } + of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); + fdt = copy_device_tree(fdt); + } + + __unflatten_device_tree(fdt, NULL, &of_root, early_init_dt_alloc_memory_arch, false); /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ |