diff options
Diffstat (limited to 'arch/arm/boot/compressed/atags_to_fdt.c')
-rw-r--r-- | arch/arm/boot/compressed/atags_to_fdt.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c new file mode 100644 index 00000000000..6ce11c48117 --- /dev/null +++ b/arch/arm/boot/compressed/atags_to_fdt.c @@ -0,0 +1,97 @@ +#include <asm/setup.h> +#include <libfdt.h> + +static int node_offset(void *fdt, const char *node_path) +{ + int offset = fdt_path_offset(fdt, node_path); + if (offset == -FDT_ERR_NOTFOUND) + offset = fdt_add_subnode(fdt, 0, node_path); + return offset; +} + +static int setprop(void *fdt, const char *node_path, const char *property, + uint32_t *val_array, int size) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop(fdt, offset, property, val_array, size); +} + +static int setprop_string(void *fdt, const char *node_path, + const char *property, const char *string) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop_string(fdt, offset, property, string); +} + +static int setprop_cell(void *fdt, const char *node_path, + const char *property, uint32_t val) +{ + int offset = node_offset(fdt, node_path); + if (offset < 0) + return offset; + return fdt_setprop_cell(fdt, offset, property, val); +} + +/* + * Convert and fold provided ATAGs into the provided FDT. + * + * REturn values: + * = 0 -> pretend success + * = 1 -> bad ATAG (may retry with another possible ATAG pointer) + * < 0 -> error from libfdt + */ +int atags_to_fdt(void *atag_list, void *fdt, int total_space) +{ + struct tag *atag = atag_list; + uint32_t mem_reg_property[2 * NR_BANKS]; + int memcount = 0; + int ret; + + /* make sure we've got an aligned pointer */ + if ((u32)atag_list & 0x3) + return 1; + + /* if we get a DTB here we're done already */ + if (*(u32 *)atag_list == fdt32_to_cpu(FDT_MAGIC)) + return 0; + + /* validate the ATAG */ + if (atag->hdr.tag != ATAG_CORE || + (atag->hdr.size != tag_size(tag_core) && + atag->hdr.size != 2)) + return 1; + + /* let's give it all the room it could need */ + ret = fdt_open_into(fdt, fdt, total_space); + if (ret < 0) + return ret; + + for_each_tag(atag, atag_list) { + if (atag->hdr.tag == ATAG_CMDLINE) { + setprop_string(fdt, "/chosen", "bootargs", + atag->u.cmdline.cmdline); + } else if (atag->hdr.tag == ATAG_MEM) { + if (memcount >= sizeof(mem_reg_property)/4) + continue; + mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.start); + mem_reg_property[memcount++] = cpu_to_fdt32(atag->u.mem.size); + } else if (atag->hdr.tag == ATAG_INITRD2) { + uint32_t initrd_start, initrd_size; + initrd_start = atag->u.initrd.start; + initrd_size = atag->u.initrd.size; + setprop_cell(fdt, "/chosen", "linux,initrd-start", + initrd_start); + setprop_cell(fdt, "/chosen", "linux,initrd-end", + initrd_start + initrd_size); + } + } + + if (memcount) + setprop(fdt, "/memory", "reg", mem_reg_property, 4*memcount); + + return fdt_pack(fdt); +} |