From: Dirk Brandewie <[email protected]> Add support for specifying a "compatible" string from the kernel command line and functions for the platform to find the compatible blob present in the kernel image if any.
Signed-off-by: Dirk Brandewie <[email protected]> --- drivers/of/fdt.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 9 ++++++++ 2 files changed, 61 insertions(+), 0 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index c1360e0..07fe4c6 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -604,3 +604,55 @@ void __init unflatten_device_tree(void) pr_debug(" <- unflatten_device_tree()\n"); } + +#ifndef MODULE +#ifdef CONFIG_OF_FLATTREE +static char dtb_compat_name[MAX_DTB_COMPAT_STR] = ""; + +char __init *of_get_dtb_compatible_string(void) +{ + return dtb_compat_name; +} + +#ifdef CONFIG_KERNEL_DTB +extern char __dtb_start[]; +extern char __dtb_end[]; + +void *of_find_compatible_dtb(char *name) +{ + void *rc = NULL; + char *hdr; + unsigned long node, root; + struct boot_param_header *blob, *orig_initial_boot_params; + + orig_initial_boot_params = initial_boot_params; + + if (__dtb_start != __dtb_end){ + blob = (struct boot_param_header *)__dtb_start; + do{ + node = ((unsigned long)blob) + + be32_to_cpu(blob->off_dt_struct); + initial_boot_params = blob; + root = of_get_flat_dt_root(); + if (of_flat_dt_is_compatible(root, name) > 0) { + rc = (void*) blob; + break; + } + blob = (unsigned long)blob+be32_to_cpu(blob->totalsize); + }while (blob < (struct boot_param_header *)__dtb_end); + } + if (rc == NULL) + initial_boot_params = orig_initial_boot_params; + return rc; +} +#endif + +static int __init dtb_compat_setup(char *line) +{ + strncpy(dtb_compat_name, line, MAX_DTB_COMPAT_STR); + return 1; +} + +__setup("dtb_compat=", dtb_compat_setup); +#endif +#endif diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 7bbf5b3..181e413 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -58,6 +58,8 @@ struct boot_param_header { }; #if defined(CONFIG_OF_FLATTREE) +#define MAX_DTB_COMPAT_STR 64 + /* TBD: Temporary export of fdt globals - remove when code fully merged */ extern int __initdata dt_root_addr_cells; extern int __initdata dt_root_size_cells; @@ -82,6 +84,13 @@ extern void early_init_dt_add_memory_arch(u64 base, u64 size); extern u64 early_init_dt_alloc_memory_arch(u64 size, u64 align); extern u64 dt_mem_next_cell(int s, __be32 **cellp); +extern char *of_get_dtb_compatible_string(void); +#ifdef CONFIG_KERNEL_DTB +extern void *of_find_compatible_dtb(char *name); +#else +static inline void *of_find_compatible_dtb(char *name) {return 0;} + +#endif /* * If BLK_DEV_INITRD, the fdt early init code will call this function, * to be provided by the arch code. start and end are specified as -- 1.7.2.3 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
