apps/fdtgen/fdt_utils.c

/*
 * SPDX-License-Identifier: GPL-2.0-only
 * Copyright Linux
 *
 * In part derived from linux/scripts/dtc/fdtdump.c
 */

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <limits.h>
#include <inttypes.h>
#include <ctype.h>
#include <stdbool.h>

#include <libfdt.h>
#include "fdt_utils.h"

#define FDT_ALIGN(x, a) (((x) + ((a) - 1)) & ~((a) - 1))
#define PALIGN(p, a) ((void *)(FDT_ALIGN((unsigned long)(p), (a))))
#define GET_CELL(p) (p += 4, *((const uint32_t *)(p-4)))

bool util_is_printable_string(const void *data, int len)
{
    const char *s = data;
    const char *ss, *se;

    if (len == 0) {
        return 0;
    }

    if (s[len - 1] != '\0') {
        return 0;
    }

    se = s + len;

    while (s < se) {
        ss = s;
        while (s < se && *s && isprint((unsigned char)*s)) {
            s++;
        }

        if (*s != '\0' || s == ss) {
            return 0;
        }

        s++;
    }

    return 1;
}

static void print_data(const char *data, int len)
{
    int i;
    const char *p = data;

    if (len == 0) {
        return;
    }

    if (util_is_printable_string(data, len)) {
        printf(" = \"%s\"", (const char *)data);
    } else if ((len % 4) == 0) {
        printf(" = <");
        for (i = 0; i < len; i += 4)
            printf("0x%08x%s", fdt32_to_cpu(GET_CELL(p)),
                   i < (len - 4) ? " " : "");
        printf(">");
    } else {
        printf(" = [");
        for (i = 0; i < len; i++) {
            printf("%02x%s", *p++, i < len - 1 ? " " : "");
        }
        printf("]");
    }
}

void dump_blob(void *blob)
{
    struct fdt_header *bph = blob;
    uint32_t off_mem_rsvmap = fdt32_to_cpu(bph->off_mem_rsvmap);
    uint32_t off_dt = fdt32_to_cpu(bph->off_dt_struct);
    uint32_t off_str = fdt32_to_cpu(bph->off_dt_strings);
    struct fdt_reserve_entry *p_rsvmap =
        (struct fdt_reserve_entry *)((char *)blob + off_mem_rsvmap);
    const char *p_struct = (const char *)blob + off_dt;
    const char *p_strings = (const char *)blob + off_str;
    uint32_t version = fdt32_to_cpu(bph->version);
    uint32_t totalsize = fdt32_to_cpu(bph->totalsize);
    uint32_t tag;
    const char *p, *s, *t;
    int depth, sz, shift;
    int i;
    uint64_t addr, size;

    depth = 0;
    shift = 4;

    printf("/dts-v1/;\n");
    printf("// magic:\t\t0x%x\n", fdt32_to_cpu(bph->magic));
    printf("// totalsize:\t\t0x%x (%d)\n", totalsize, totalsize);
    printf("// off_dt_struct:\t0x%x\n", off_dt);
    printf("// off_dt_strings:\t0x%x\n", off_str);
    printf("// off_mem_rsvmap:\t0x%x\n", off_mem_rsvmap);
    printf("// version:\t\t%d\n", version);
    printf("// last_comp_version:\t%d\n",
           fdt32_to_cpu(bph->last_comp_version));
    if (version >= 2)
        printf("// boot_cpuid_phys:\t0x%x\n",
               fdt32_to_cpu(bph->boot_cpuid_phys));

    if (version >= 3)
        printf("// size_dt_strings:\t0x%x\n",
               fdt32_to_cpu(bph->size_dt_strings));
    if (version >= 17)
        printf("// size_dt_struct:\t0x%x\n",
               fdt32_to_cpu(bph->size_dt_struct));
    printf("\n");

    for (i = 0; ; i++) {
        addr = fdt64_to_cpu(p_rsvmap[i].address);
        size = fdt64_to_cpu(p_rsvmap[i].size);
        if (addr == 0 && size == 0) {
            break;
        }

        printf("/memreserve/ %llx %llx;\n",
               (unsigned long long)addr, (unsigned long long)size);
    }

    p = p_struct;
    while ((tag = fdt32_to_cpu(GET_CELL(p))) != FDT_END) {

        if (tag == FDT_BEGIN_NODE) {
            s = p;
            p = PALIGN(p + strlen(s) + 1, 4);

            if (*s == '\0') {
                s = "/";
            }

            printf("%*s%s {\n", depth * shift, "", s);

            depth++;
            continue;
        }

        if (tag == FDT_END_NODE) {
            depth--;

            printf("%*s};\n", depth * shift, "");
            continue;
        }

        if (tag == FDT_NOP) {
            printf("%*s// [NOP]\n", depth * shift, "");
            continue;
        }

        if (tag != FDT_PROP) {
            fprintf(stderr, "%*s ** Unknown tag 0x%08x\n", depth * shift, "", tag);
            break;
        }
        sz = fdt32_to_cpu(GET_CELL(p));
        s = p_strings + fdt32_to_cpu(GET_CELL(p));
        if (version < 16 && sz >= 8) {
            p = PALIGN(p, 8);
        }
        t = p;

        p = PALIGN(p + sz, 4);

        printf("%*s%s", depth * shift, "", s);
        print_data(t, sz);
        printf(";\n");
    }
}