| // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) |
| /* |
| * libfdt - Flat Device Tree manipulation |
| * Copyright (C) 2006 David Gibson, IBM Corporation. |
| */ |
| #include "libfdt_env.h" |
| |
| #include <fdt.h> |
| #include <libfdt.h> |
| |
| #include "libfdt_internal.h" |
| |
| static int fdt_sw_probe_(void *fdt) |
| { |
| if (fdt_chk_basic()) { |
| if (fdt_magic(fdt) == FDT_MAGIC) |
| return -FDT_ERR_BADSTATE; |
| else if (fdt_magic(fdt) != FDT_SW_MAGIC) |
| return -FDT_ERR_BADMAGIC; |
| } |
| |
| return 0; |
| } |
| |
| #define FDT_SW_PROBE(fdt) \ |
| { \ |
| int err; \ |
| if (fdt_chk_basic() && (err = fdt_sw_probe_(fdt)) != 0) \ |
| return err; \ |
| } |
| |
| /* 'memrsv' state: Initial state after fdt_create() |
| * |
| * Allowed functions: |
| * fdt_add_reservmap_entry() |
| * fdt_finish_reservemap() [moves to 'struct' state] |
| */ |
| static int fdt_sw_probe_memrsv_(void *fdt) |
| { |
| int err = fdt_sw_probe_(fdt); |
| if (err) |
| return err; |
| |
| if (fdt_chk_extra() && fdt_off_dt_strings(fdt) != 0) |
| return -FDT_ERR_BADSTATE; |
| return 0; |
| } |
| |
| #define FDT_SW_PROBE_MEMRSV(fdt) \ |
| { \ |
| int err; \ |
| if (fdt_chk_extra() && (err = fdt_sw_probe_memrsv_(fdt)) != 0) \ |
| return err; \ |
| } |
| |
| /* 'struct' state: Enter this state after fdt_finish_reservemap() |
| * |
| * Allowed functions: |
| * fdt_begin_node() |
| * fdt_end_node() |
| * fdt_property*() |
| * fdt_finish() [moves to 'complete' state] |
| */ |
| static int fdt_sw_probe_struct_(void *fdt) |
| { |
| int err; |
| |
| if (!fdt_chk_extra()) |
| return 0; |
| err = fdt_sw_probe_(fdt); |
| if (err) |
| return err; |
| |
| if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) |
| return -FDT_ERR_BADSTATE; |
| return 0; |
| } |
| |
| #define FDT_SW_PROBE_STRUCT(fdt) \ |
| { \ |
| int err; \ |
| if (fdt_chk_extra() && (err = fdt_sw_probe_struct_(fdt)) != 0) \ |
| return err; \ |
| } |
| |
| static inline uint32_t sw_flags(void *fdt) |
| { |
| /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */ |
| return fdt_last_comp_version(fdt); |
| } |
| |
| /* 'complete' state: Enter this state after fdt_finish() |
| * |
| * Allowed functions: none |
| */ |
| |
| static void *fdt_grab_space_(void *fdt, size_t len) |
| { |
| int offset = fdt_size_dt_struct(fdt); |
| int spaceleft; |
| |
| spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt) |
| - fdt_size_dt_strings(fdt); |
| |
| if ((offset + len < offset) || (offset + len > spaceleft)) |
| return NULL; |
| |
| fdt_set_size_dt_struct(fdt, offset + len); |
| return fdt_offset_ptr_w_(fdt, offset); |
| } |
| |
| int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags) |
| { |
| const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header), |
| sizeof(struct fdt_reserve_entry)); |
| void *fdt = buf; |
| |
| if (bufsize < hdrsize) |
| return -FDT_ERR_NOSPACE; |
| |
| if (flags & ~FDT_CREATE_FLAGS_ALL) |
| return -FDT_ERR_BADFLAGS; |
| |
| memset(buf, 0, bufsize); |
| |
| /* |
| * magic and last_comp_version keep intermediate state during the fdt |
| * creation process, which is replaced with the proper FDT format by |
| * fdt_finish(). |
| * |
| * flags should be accessed with sw_flags(). |
| */ |
| fdt_set_magic(fdt, FDT_SW_MAGIC); |
| fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION); |
| fdt_set_last_comp_version(fdt, flags); |
| |
| fdt_set_totalsize(fdt, bufsize); |
| |
| fdt_set_off_mem_rsvmap(fdt, hdrsize); |
| fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt)); |
| fdt_set_off_dt_strings(fdt, 0); |
| |
| return 0; |
| } |
| |
| int fdt_create(void *buf, int bufsize) |
| { |
| return fdt_create_with_flags(buf, bufsize, 0); |
| } |
| |
| int fdt_resize(void *fdt, void *buf, int bufsize) |
| { |
| size_t headsize, tailsize; |
| char *oldtail, *newtail; |
| |
| FDT_SW_PROBE(fdt); |
| |
| headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); |
| tailsize = fdt_size_dt_strings(fdt); |
| |
| if (fdt_chk_extra() && (headsize + tailsize) > fdt_totalsize(fdt)) |
| return -FDT_ERR_INTERNAL; |
| |
| if ((headsize + tailsize) > bufsize) |
| return -FDT_ERR_NOSPACE; |
| |
| oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; |
| newtail = (char *)buf + bufsize - tailsize; |
| |
| /* Two cases to avoid clobbering data if the old and new |
| * buffers partially overlap */ |
| if (buf <= fdt) { |
| memmove(buf, fdt, headsize); |
| memmove(newtail, oldtail, tailsize); |
| } else { |
| memmove(newtail, oldtail, tailsize); |
| memmove(buf, fdt, headsize); |
| } |
| |
| fdt_set_totalsize(buf, bufsize); |
| if (fdt_off_dt_strings(buf)) |
| fdt_set_off_dt_strings(buf, bufsize); |
| |
| return 0; |
| } |
| |
| int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size) |
| { |
| struct fdt_reserve_entry *re; |
| int offset; |
| |
| FDT_SW_PROBE_MEMRSV(fdt); |
| |
| offset = fdt_off_dt_struct(fdt); |
| if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) |
| return -FDT_ERR_NOSPACE; |
| |
| re = (struct fdt_reserve_entry *)((char *)fdt + offset); |
| re->address = cpu_to_fdt64(addr); |
| re->size = cpu_to_fdt64(size); |
| |
| fdt_set_off_dt_struct(fdt, offset + sizeof(*re)); |
| |
| return 0; |
| } |
| |
| int fdt_finish_reservemap(void *fdt) |
| { |
| int err = fdt_add_reservemap_entry(fdt, 0, 0); |
| |
| if (err) |
| return err; |
| |
| fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt)); |
| return 0; |
| } |
| |
| int fdt_begin_node(void *fdt, const char *name) |
| { |
| struct fdt_node_header *nh; |
| int namelen; |
| |
| FDT_SW_PROBE_STRUCT(fdt); |
| |
| namelen = strlen(name) + 1; |
| nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen)); |
| if (! nh) |
| return -FDT_ERR_NOSPACE; |
| |
| nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); |
| memcpy(nh->name, name, namelen); |
| return 0; |
| } |
| |
| int fdt_end_node(void *fdt) |
| { |
| fdt32_t *en; |
| |
| FDT_SW_PROBE_STRUCT(fdt); |
| |
| en = fdt_grab_space_(fdt, FDT_TAGSIZE); |
| if (! en) |
| return -FDT_ERR_NOSPACE; |
| |
| *en = cpu_to_fdt32(FDT_END_NODE); |
| return 0; |
| } |
| |
| static int fdt_add_string_(void *fdt, const char *s) |
| { |
| char *strtab = (char *)fdt + fdt_totalsize(fdt); |
| int strtabsize = fdt_size_dt_strings(fdt); |
| int len = strlen(s) + 1; |
| int struct_top, offset; |
| |
| offset = -strtabsize - len; |
| struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); |
| if (fdt_totalsize(fdt) + offset < struct_top) |
| return 0; /* no more room :( */ |
| |
| memcpy(strtab + offset, s, len); |
| fdt_set_size_dt_strings(fdt, strtabsize + len); |
| return offset; |
| } |
| |
| /* Must only be used to roll back in case of error */ |
| static void fdt_del_last_string_(void *fdt, const char *s) |
| { |
| int strtabsize = fdt_size_dt_strings(fdt); |
| int len = strlen(s) + 1; |
| |
| fdt_set_size_dt_strings(fdt, strtabsize - len); |
| } |
| |
| static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) |
| { |
| char *strtab = (char *)fdt + fdt_totalsize(fdt); |
| int strtabsize = fdt_size_dt_strings(fdt); |
| const char *p; |
| |
| *allocated = 0; |
| |
| p = fdt_find_string_(strtab - strtabsize, strtabsize, s); |
| if (p) |
| return p - strtab; |
| |
| *allocated = 1; |
| |
| return fdt_add_string_(fdt, s); |
| } |
| |
| int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp) |
| { |
| struct fdt_property *prop; |
| int nameoff; |
| int allocated; |
| |
| FDT_SW_PROBE_STRUCT(fdt); |
| |
| /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */ |
| if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) { |
| allocated = 1; |
| nameoff = fdt_add_string_(fdt, name); |
| } else { |
| nameoff = fdt_find_add_string_(fdt, name, &allocated); |
| } |
| if (nameoff == 0) |
| return -FDT_ERR_NOSPACE; |
| |
| prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len)); |
| if (! prop) { |
| if (allocated) |
| fdt_del_last_string_(fdt, name); |
| return -FDT_ERR_NOSPACE; |
| } |
| |
| prop->tag = cpu_to_fdt32(FDT_PROP); |
| prop->nameoff = cpu_to_fdt32(nameoff); |
| prop->len = cpu_to_fdt32(len); |
| *valp = prop->data; |
| return 0; |
| } |
| |
| int fdt_property(void *fdt, const char *name, const void *val, int len) |
| { |
| void *ptr; |
| int ret; |
| |
| ret = fdt_property_placeholder(fdt, name, len, &ptr); |
| if (ret) |
| return ret; |
| memcpy(ptr, val, len); |
| return 0; |
| } |
| |
| int fdt_finish(void *fdt) |
| { |
| char *p = (char *)fdt; |
| fdt32_t *end; |
| int oldstroffset, newstroffset; |
| uint32_t tag; |
| int offset, nextoffset; |
| |
| FDT_SW_PROBE_STRUCT(fdt); |
| |
| /* Add terminator */ |
| end = fdt_grab_space_(fdt, sizeof(*end)); |
| if (! end) |
| return -FDT_ERR_NOSPACE; |
| *end = cpu_to_fdt32(FDT_END); |
| |
| /* Relocate the string table */ |
| oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt); |
| newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); |
| memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt)); |
| fdt_set_off_dt_strings(fdt, newstroffset); |
| |
| /* Walk the structure, correcting string offsets */ |
| offset = 0; |
| while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) { |
| if (tag == FDT_PROP) { |
| struct fdt_property *prop = |
| fdt_offset_ptr_w_(fdt, offset); |
| int nameoff; |
| |
| nameoff = fdt32_to_cpu(prop->nameoff); |
| nameoff += fdt_size_dt_strings(fdt); |
| prop->nameoff = cpu_to_fdt32(nameoff); |
| } |
| offset = nextoffset; |
| } |
| if (nextoffset < 0) |
| return nextoffset; |
| |
| /* Finally, adjust the header */ |
| fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt)); |
| |
| /* And fix up fields that were keeping intermediate state. */ |
| fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION); |
| fdt_set_magic(fdt, FDT_MAGIC); |
| |
| return 0; |
| } |