int fdt_create(void *buf, int bufsize)
{
void *fdt = buf;
if (bufsize < (int)sizeof(struct fdt_header))
return -FDT_ERR_NOSPACE;
memset(buf, 0, bufsize);
fdt_set_magic(fdt, FDT_SW_MAGIC);
fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
fdt_set_totalsize(fdt, bufsize);
fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
sizeof(struct fdt_reserve_entry)));
fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
fdt_set_off_dt_strings(fdt, bufsize);
return 0;
}
/**
* dump_fdt_regions() - Dump regions of an FDT as binary data
*
* This dumps an FDT as binary, but only certain regions of it. This is the
* final stage of the grep - we have a list of regions we want to dump,
* and this function dumps them.
*
* The output of this function may or may not be a valid FDT. To ensure it
* is, these disp->flags must be set:
*
* FDT_REG_SUPERNODES: ensures that subnodes are preceeded by their
* parents. Without this option, fragments of subnode data may be
* output without the supernodes above them. This is useful for
* hashing but cannot produce a valid FDT.
* FDT_REG_ADD_STRING_TAB: Adds a string table to the end of the FDT.
* Without this none of the properties will have names
* FDT_REG_ADD_MEM_RSVMAP: Adds a mem_rsvmap table - an FDT is invalid
* without this.
*
* @disp: Display structure, holding info about our options
* @blob: FDT blob to display
* @region: List of regions to display
* @count: Number of regions
* @out: Output destination
*/
static int dump_fdt_regions(struct display_info *disp, const void *blob,
struct fdt_region region[], int count, char *out)
{
struct fdt_header *fdt;
int size, struct_start;
int ptr;
int i;
/* Set up a basic header (even if we don't actually write it) */
fdt = (struct fdt_header *)out;
memset(fdt, '\0', sizeof(*fdt));
fdt_set_magic(fdt, FDT_MAGIC);
struct_start = FDT_ALIGN(sizeof(struct fdt_header),
sizeof(struct fdt_reserve_entry));
fdt_set_off_mem_rsvmap(fdt, struct_start);
fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
/*
* Calculate the total size of the regions we are writing out. The
* first will be the mem_rsvmap if the FDT_REG_ADD_MEM_RSVMAP flag
* is set. The last will be the string table if FDT_REG_ADD_STRING_TAB
* is set.
*/
for (i = size = 0; i < count; i++)
size += region[i].size;
/* Bring in the mem_rsvmap section from the old file if requested */
if (count > 0 && (disp->flags & FDT_REG_ADD_MEM_RSVMAP)) {
struct_start += region[0].size;
size -= region[0].size;
}
fdt_set_off_dt_struct(fdt, struct_start);
/* Update the header to have the correct offsets/sizes */
if (count >= 2 && (disp->flags & FDT_REG_ADD_STRING_TAB)) {
int str_size;
str_size = region[count - 1].size;
fdt_set_size_dt_struct(fdt, size - str_size);
fdt_set_off_dt_strings(fdt, struct_start + size - str_size);
fdt_set_size_dt_strings(fdt, str_size);
fdt_set_totalsize(fdt, struct_start + size);
}
/* Write the header if required */
ptr = 0;
if (disp->header) {
ptr = sizeof(*fdt);
while (ptr < fdt_off_mem_rsvmap(fdt))
out[ptr++] = '\0';
}
/* Output all the nodes including any mem_rsvmap/string table */
for (i = 0; i < count; i++) {
struct fdt_region *reg = ®ion[i];
memcpy(out + ptr, (const char *)blob + reg->offset, reg->size);
ptr += reg->size;
}
return ptr;
}