[people/ms/u-boot.git] / board / gdsys / p1022 / controlcenterd-id.c

/*
 * (C) Copyright 2013
 * Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

/* TODO: some more #ifdef's to avoid unneeded code for stage 1 / stage 2 */

#ifdef CCDM_ID_DEBUG
#define DEBUG
#endif

#include <common.h>
#include <malloc.h>
#include <fs.h>
#include <i2c.h>
#include <mmc.h>
#include <tpm.h>
#include <u-boot/sha1.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <pca9698.h>

#undef CCDM_FIRST_STAGE
#undef CCDM_SECOND_STAGE
#undef CCDM_AUTO_FIRST_STAGE

#ifdef CONFIG_DEVELOP
#define CCDM_DEVELOP
#endif

#ifdef CONFIG_TRAILBLAZER
#define CCDM_FIRST_STAGE
#undef CCDM_SECOND_STAGE
#else
#undef CCDM_FIRST_STAGE
#define CCDM_SECOND_STAGE
#endif

#if defined(CCDM_DEVELOP) && defined(CCDM_SECOND_STAGE) && \
        !defined(CCCM_FIRST_STAGE)
#define CCDM_AUTO_FIRST_STAGE
#endif

/* enums from TCG specs */
enum {
        /* capability areas */
        TPM_CAP_NV_INDEX        = 0x00000011,
        TPM_CAP_HANDLE          = 0x00000014,
        /* resource types */
        TPM_RT_KEY      = 0x00000001,
};

/* CCDM specific contants */
enum {
        /* NV indices */
        NV_COMMON_DATA_INDEX    = 0x40000001,
        /* magics for key blob chains */
        MAGIC_KEY_PROGRAM       = 0x68726500,
        MAGIC_HMAC              = 0x68616300,
        MAGIC_END_OF_CHAIN      = 0x00000000,
        /* sizes */
        NV_COMMON_DATA_MIN_SIZE = 3 * sizeof(uint64_t) + 2 * sizeof(uint16_t),
};

/* other constants */
enum {
        ESDHC_BOOT_IMAGE_SIG_OFS        = 0x40,
        ESDHC_BOOT_IMAGE_SIZE_OFS       = 0x48,
        ESDHC_BOOT_IMAGE_ADDR_OFS       = 0x50,
        ESDHC_BOOT_IMAGE_TARGET_OFS     = 0x58,
        ESDHC_BOOT_IMAGE_ENTRY_OFS      = 0x60,
};

enum {
        I2C_SOC_0 = 0,
        I2C_SOC_1 = 1,
};

struct key_program {
        uint32_t magic;
        uint32_t code_crc;
        uint32_t code_size;
        uint8_t code[];
};

struct h_reg {
        bool valid;
        uint8_t digest[20];
};


enum access_mode {
        HREG_NONE       = 0,
        HREG_RD         = 1,
        HREG_WR         = 2,
        HREG_RDWR       = 3,
};

/* register constants */
enum {
        FIX_HREG_DEVICE_ID_HASH = 0,
        FIX_HREG_SELF_HASH      = 1,
        FIX_HREG_STAGE2_HASH    = 2,
        FIX_HREG_VENDOR         = 3,
        COUNT_FIX_HREGS
};


/* hre opcodes */
enum {
        /* opcodes w/o data */
        HRE_NOP         = 0x00,
        HRE_SYNC        = HRE_NOP,
        HRE_CHECK0      = 0x01,
        /* opcodes w/o data, w/ sync dst */
        /* opcodes w/ data */
        HRE_LOAD        = 0x81,
        /* opcodes w/data, w/sync dst */
        HRE_XOR         = 0xC1,
        HRE_AND         = 0xC2,
        HRE_OR          = 0xC3,
        HRE_EXTEND      = 0xC4,
        HRE_LOADKEY     = 0xC5,
};

/* hre errors */
enum {
        HRE_E_OK        = 0,
        HRE_E_TPM_FAILURE,
        HRE_E_INVALID_HREG,
};

static uint64_t device_id;
static uint64_t device_cl;
static uint64_t device_type;

static uint32_t platform_key_handle;

static void(*bl2_entry)(void);

static struct h_reg pcr_hregs[24];
static struct h_reg fix_hregs[COUNT_FIX_HREGS];
static struct h_reg var_hregs[8];
static uint32_t hre_tpm_err;
static int hre_err = HRE_E_OK;

#define IS_PCR_HREG(spec) ((spec) & 0x20)
#define IS_FIX_HREG(spec) (((spec) & 0x38) == 0x08)
#define IS_VAR_HREG(spec) (((spec) & 0x38) == 0x10)
#define HREG_IDX(spec) ((spec) & (IS_PCR_HREG(spec) ? 0x1f : 0x7))


static const uint8_t prg_stage1_prepare[] = {
        0x00, 0x20, 0x00, 0x00, /* opcode: SYNC f0 */
        0x00, 0x24, 0x00, 0x00, /* opcode: SYNC f1 */
        0x01, 0x80, 0x00, 0x00, /* opcode: CHECK0 PCR0 */
        0x81, 0x22, 0x00, 0x00, /* opcode: LOAD PCR0, f0 */
        0x01, 0x84, 0x00, 0x00, /* opcode: CHECK0 PCR1 */
        0x81, 0x26, 0x10, 0x00, /* opcode: LOAD PCR1, f1 */
        0x01, 0x88, 0x00, 0x00, /* opcode: CHECK0 PCR2 */
        0x81, 0x2a, 0x20, 0x00, /* opcode: LOAD PCR2, f2 */
        0x01, 0x8c, 0x00, 0x00, /* opcode: CHECK0 PCR3 */
        0x81, 0x2e, 0x30, 0x00, /* opcode: LOAD PCR3, f3 */
};

static const uint8_t prg_stage2_prepare[] = {
        0x00, 0x80, 0x00, 0x00, /* opcode: SYNC PCR0 */
        0x00, 0x84, 0x00, 0x00, /* opcode: SYNC PCR1 */
        0x00, 0x88, 0x00, 0x00, /* opcode: SYNC PCR2 */
        0x00, 0x8c, 0x00, 0x00, /* opcode: SYNC PCR3 */
        0x00, 0x90, 0x00, 0x00, /* opcode: SYNC PCR4 */
};

static const uint8_t prg_stage2_success[] = {
        0x81, 0x02, 0x40, 0x14, /* opcode: LOAD PCR4, #<20B data> */
        0x48, 0xfd, 0x95, 0x17, 0xe7, 0x54, 0x6b, 0x68, /* data */
        0x92, 0x31, 0x18, 0x05, 0xf8, 0x58, 0x58, 0x3c, /* data */
        0xe4, 0xd2, 0x81, 0xe0, /* data */
};

static const uint8_t prg_stage_fail[] = {
        0x81, 0x01, 0x00, 0x14, /* opcode: LOAD v0, #<20B data> */
        0xc0, 0x32, 0xad, 0xc1, 0xff, 0x62, 0x9c, 0x9b, /* data */
        0x66, 0xf2, 0x27, 0x49, 0xad, 0x66, 0x7e, 0x6b, /* data */
        0xea, 0xdf, 0x14, 0x4b, /* data */
        0x81, 0x42, 0x30, 0x00, /* opcode: LOAD PCR3, v0 */
        0x81, 0x42, 0x40, 0x00, /* opcode: LOAD PCR4, v0 */
};

static const uint8_t vendor[] = "Guntermann & Drunck";


/**
 * @brief read a bunch of data from MMC into memory.
 *
 * @param mmc   pointer to the mmc structure to use.
 * @param src   offset where the data starts on MMC/SD device (in bytes).
 * @param dst   pointer to the location where the read data should be stored.
 * @param size  number of bytes to read from the MMC/SD device.
 * @return number of bytes read or -1 on error.
 */
static int ccdm_mmc_read(struct mmc *mmc, u64 src, u8 *dst, int size)
{
        int result = 0;
        u32 blk_len, ofs;
        ulong block_no, n, cnt;
        u8 *tmp_buf = NULL;

        if (size <= 0)
                goto end;

        blk_len = mmc->read_bl_len;
        tmp_buf = malloc(blk_len);
        if (!tmp_buf)
                goto failure;
        block_no = src / blk_len;
        ofs = src % blk_len;

        if (ofs) {
                n = mmc->block_dev.block_read(&mmc->block_dev, block_no++, 1,
                        tmp_buf);
                if (!n)
                        goto failure;
                result = min(size, (int)(blk_len - ofs));
                memcpy(dst, tmp_buf + ofs, result);
                dst += result;
                size -= result;
        }
        cnt = size / blk_len;
        if (cnt) {
                n = mmc->block_dev.block_read(&mmc->block_dev, block_no, cnt,
                        dst);
                if (n != cnt)
                        goto failure;
                size -= cnt * blk_len;
                result += cnt * blk_len;
                dst += cnt * blk_len;
                block_no += cnt;
        }
        if (size) {
                n = mmc->block_dev.block_read(&mmc->block_dev, block_no++, 1,
                        tmp_buf);
                if (!n)
                        goto failure;
                memcpy(dst, tmp_buf, size);
                result += size;
        }
        goto end;
failure:
        result = -1;
end:
        if (tmp_buf)
                free(tmp_buf);
        return result;
}

/**
 * @brief returns a location where the 2nd stage bootloader can be(/ is) placed.
 *
 * @return pointer to the location for/of the 2nd stage bootloader
 */
static u8 *get_2nd_stage_bl_location(ulong target_addr)
{
        ulong addr;
#ifdef CCDM_SECOND_STAGE
        addr = getenv_ulong("loadaddr", 16, CONFIG_LOADADDR);
#else
        addr = target_addr;
#endif
        return (u8 *)(addr);
}


#ifdef CCDM_SECOND_STAGE
/**
 * @brief returns a location where the image can be(/ is) placed.
 *
 * @return pointer to the location for/of the image
 */
static u8 *get_image_location(void)
{
        ulong addr;
        /* TODO use other area? */
        addr = getenv_ulong("loadaddr", 16, CONFIG_LOADADDR);
        return (u8 *)(addr);
}
#endif

/**
 * @brief get the size of a given (TPM) NV area
 * @param index NV index of the area to get size for
 * @param size  pointer to the size
 * @return 0 on success, != 0 on error
 */
static int get_tpm_nv_size(uint32_t index, uint32_t *size)
{
        uint32_t err;
        uint8_t info[72];
        uint8_t *ptr;
        uint16_t v16;

        err = tpm_get_capability(TPM_CAP_NV_INDEX, index,
                info, sizeof(info));
        if (err) {
                printf("tpm_get_capability(CAP_NV_INDEX, %08x) failed: %u\n",
                       index, err);
                return 1;
        }

        /* skip tag and nvIndex */
        ptr = info + 6;
        /* skip 2 pcr info fields */
        v16 = get_unaligned_be16(ptr);
        ptr += 2 + v16 + 1 + 20;
        v16 = get_unaligned_be16(ptr);
        ptr += 2 + v16 + 1 + 20;
        /* skip permission and flags */
        ptr += 6 + 3;

        *size = get_unaligned_be32(ptr);
        return 0;
}

/**
 * @brief search for a key by usage auth and pub key hash.
 * @param auth  usage auth of the key to search for
 * @param pubkey_digest (SHA1) hash of the pub key structure of the key
 * @param[out] handle   the handle of the key iff found
 * @return 0 if key was found in TPM; != 0 if not.
 */
static int find_key(const uint8_t auth[20], const uint8_t pubkey_digest[20],
                uint32_t *handle)
{
        uint16_t key_count;
        uint32_t key_handles[10];
        uint8_t buf[288];
        uint8_t *ptr;
        uint32_t err;
        uint8_t digest[20];
        size_t buf_len;
        unsigned int i;

        /* fetch list of already loaded keys in the TPM */
        err = tpm_get_capability(TPM_CAP_HANDLE, TPM_RT_KEY, buf, sizeof(buf));
        if (err)
                return -1;
        key_count = get_unaligned_be16(buf);
        ptr = buf + 2;
        for (i = 0; i < key_count; ++i, ptr += 4)
                key_handles[i] = get_unaligned_be32(ptr);

        /* now search a(/ the) key which we can access with the given auth */
        for (i = 0; i < key_count; ++i) {
                buf_len = sizeof(buf);
                err = tpm_get_pub_key_oiap(key_handles[i], auth, buf, &buf_len);
                if (err && err != TPM_AUTHFAIL)
                        return -1;
                if (err)
                        continue;
                sha1_csum(buf, buf_len, digest);
                if (!memcmp(digest, pubkey_digest, 20)) {
                        *handle = key_handles[i];
                        return 0;
                }
        }
        return 1;
}

/**
 * @brief read CCDM common data from TPM NV
 * @return 0 if CCDM common data was found and read, !=0 if something failed.
 */
static int read_common_data(void)
{
        uint32_t size;
        uint32_t err;
        uint8_t buf[256];
        sha1_context ctx;

        if (get_tpm_nv_size(NV_COMMON_DATA_INDEX, &size) ||
            size < NV_COMMON_DATA_MIN_SIZE)
                return 1;
        err = tpm_nv_read_value(NV_COMMON_DATA_INDEX,
                buf, min(sizeof(buf), size));
        if (err) {
                printf("tpm_nv_read_value() failed: %u\n", err);
                return 1;
        }

        device_id = get_unaligned_be64(buf);
        device_cl = get_unaligned_be64(buf + 8);
        device_type = get_unaligned_be64(buf + 16);

        sha1_starts(&ctx);
        sha1_update(&ctx, buf, 24);
        sha1_finish(&ctx, fix_hregs[FIX_HREG_DEVICE_ID_HASH].digest);
        fix_hregs[FIX_HREG_DEVICE_ID_HASH].valid = true;

        platform_key_handle = get_unaligned_be32(buf + 24);

        return 0;
}

/**
 * @brief compute hash of bootloader itself.
 * @param[out] dst      hash register where the hash should be stored
 * @return 0 on success, != 0 on failure.
 *
 * @note MUST be called at a time where the boot loader is accessible at the
 * configured location (; so take care when code is reallocated).
 */
static int compute_self_hash(struct h_reg *dst)
{
        sha1_csum((const uint8_t *)CONFIG_SYS_MONITOR_BASE,
                  CONFIG_SYS_MONITOR_LEN, dst->digest);
        dst->valid = true;
        return 0;
}

int ccdm_compute_self_hash(void)
{
        if (!fix_hregs[FIX_HREG_SELF_HASH].valid)
                compute_self_hash(&fix_hregs[FIX_HREG_SELF_HASH]);
        return 0;
}

/**
 * @brief compute the hash of the 2nd stage boot loader (on SD card)
 * @param[out] dst      hash register to store the computed hash
 * @return 0 on success, != 0 on failure
 *
 * Determines the size and location of the 2nd stage boot loader on SD card,
 * loads the 2nd stage boot loader and computes the (SHA1) hash value.
 * Within the 1st stage boot loader, the 2nd stage boot loader is loaded at
 * the desired memory location and the variable @a bl2_entry is set.
 *
 * @note This sets the variable @a bl2_entry to the entry point when the
 * 2nd stage boot loader is loaded at its configured memory location.
 */
static int compute_second_stage_hash(struct h_reg *dst)
{
        int result = 0;
        u32 code_len, code_offset, target_addr, exec_entry;
        struct mmc *mmc;
        u8 *load_addr = NULL;
        u8 buf[128];

        mmc = find_mmc_device(0);
        if (!mmc)
                goto failure;
        mmc_init(mmc);

        if (ccdm_mmc_read(mmc, 0, buf, sizeof(buf)) < 0)
                goto failure;

        code_offset = *(u32 *)(buf + ESDHC_BOOT_IMAGE_ADDR_OFS);
        code_len = *(u32 *)(buf + ESDHC_BOOT_IMAGE_SIZE_OFS);
        target_addr = *(u32 *)(buf + ESDHC_BOOT_IMAGE_TARGET_OFS);
        exec_entry =  *(u32 *)(buf + ESDHC_BOOT_IMAGE_ENTRY_OFS);

        load_addr = get_2nd_stage_bl_location(target_addr);
        if (load_addr == (u8 *)target_addr)
                bl2_entry = (void(*)(void))exec_entry;

        if (ccdm_mmc_read(mmc, code_offset, load_addr, code_len) < 0)
                goto failure;

        sha1_csum(load_addr, code_len, dst->digest);
        dst->valid = true;

        goto end;
failure:
        result = 1;
        bl2_entry = NULL;
end:
        return result;
}

/**
 * @brief get pointer to  hash register by specification
 * @param spec  specification of a hash register
 * @return pointer to hash register or NULL if @a spec does not qualify a
 * valid hash register; NULL else.
 */
static struct h_reg *get_hreg(uint8_t spec)
{
        uint8_t idx;

        idx = HREG_IDX(spec);
        if (IS_FIX_HREG(spec)) {
                if (idx < ARRAY_SIZE(fix_hregs))
                        return fix_hregs + idx;
                hre_err = HRE_E_INVALID_HREG;
        } else if (IS_PCR_HREG(spec)) {
                if (idx < ARRAY_SIZE(pcr_hregs))
                        return pcr_hregs + idx;
                hre_err = HRE_E_INVALID_HREG;
        } else if (IS_VAR_HREG(spec)) {
                if (idx < ARRAY_SIZE(var_hregs))
                        return var_hregs + idx;
                hre_err = HRE_E_INVALID_HREG;
        }
        return NULL;
}

/**
 * @brief get pointer of a hash register by specification and usage.
 * @param spec  specification of a hash register
 * @param mode  access mode (read or write or read/write)
 * @return pointer to hash register if found and valid; NULL else.
 *
 * This func uses @a get_reg() to determine the hash register for a given spec.
 * If a register is found it is validated according to the desired access mode.
 * The value of automatic registers (PCR register and fixed registers) is
 * loaded or computed on read access.
 */
static struct h_reg *access_hreg(uint8_t spec, enum access_mode mode)
{
        struct h_reg *result;

        result = get_hreg(spec);
        if (!result)
                return NULL;

        if (mode & HREG_WR) {
                if (IS_FIX_HREG(spec)) {
                        hre_err = HRE_E_INVALID_HREG;
                        return NULL;
                }
        }
        if (mode & HREG_RD) {
                if (!result->valid) {
                        if (IS_PCR_HREG(spec)) {
                                hre_tpm_err = tpm_pcr_read(HREG_IDX(spec),
                                        result->digest, 20);
                                result->valid = (hre_tpm_err == TPM_SUCCESS);
                        } else if (IS_FIX_HREG(spec)) {
                                switch (HREG_IDX(spec)) {
                                case FIX_HREG_DEVICE_ID_HASH:
                                        read_common_data();
                                        break;
                                case FIX_HREG_SELF_HASH:
                                        ccdm_compute_self_hash();
                                        break;
                                case FIX_HREG_STAGE2_HASH:
                                        compute_second_stage_hash(result);
                                        break;
                                case FIX_HREG_VENDOR:
                                        memcpy(result->digest, vendor, 20);
                                        result->valid = true;
                                        break;
                                }
                        } else {
                                result->valid = true;
                        }
                }
                if (!result->valid) {
                        hre_err = HRE_E_INVALID_HREG;
                        return NULL;
                }
        }

        return result;
}

static void *compute_and(void *_dst, const void *_src, size_t n)
{
        uint8_t *dst = _dst;
        const uint8_t *src = _src;
        size_t i;

        for (i = n; i-- > 0; )
                *dst++ &= *src++;

        return _dst;
}

static void *compute_or(void *_dst, const void *_src, size_t n)
{
        uint8_t *dst = _dst;
        const uint8_t *src = _src;
        size_t i;

        for (i = n; i-- > 0; )
                *dst++ |= *src++;

        return _dst;
}

static void *compute_xor(void *_dst, const void *_src, size_t n)
{
        uint8_t *dst = _dst;
        const uint8_t *src = _src;
        size_t i;

        for (i = n; i-- > 0; )
                *dst++ ^= *src++;

        return _dst;
}

static void *compute_extend(void *_dst, const void *_src, size_t n)
{
        uint8_t digest[20];
        sha1_context ctx;

        sha1_starts(&ctx);
        sha1_update(&ctx, _dst, n);
        sha1_update(&ctx, _src, n);
        sha1_finish(&ctx, digest);
        memcpy(_dst, digest, min(n, sizeof(digest)));

        return _dst;
}

static int hre_op_loadkey(struct h_reg *src_reg, struct h_reg *dst_reg,
                const void *key, size_t key_size)
{
        uint32_t parent_handle;
        uint32_t key_handle;

        if (!src_reg || !dst_reg || !src_reg->valid || !dst_reg->valid)
                return -1;
        if (find_key(src_reg->digest, dst_reg->digest, &parent_handle))
                return -1;
        hre_tpm_err = tpm_load_key2_oiap(parent_handle, key, key_size,
                src_reg->digest, &key_handle);
        if (hre_tpm_err) {
                hre_err = HRE_E_TPM_FAILURE;
                return -1;
        }
        /* TODO remember key handle somehow? */

        return 0;
}

/**
 * @brief executes the next opcode on the hash register engine.
 * @param[in,out] ip    pointer to the opcode (instruction pointer)
 * @param[in,out] code_size     (remaining) size of the code
 * @return new instruction pointer on success, NULL on error.
 */
static const uint8_t *hre_execute_op(const uint8_t **ip, size_t *code_size)
{
        bool dst_modified = false;
        uint32_t ins;
        uint8_t opcode;
        uint8_t src_spec;
        uint8_t dst_spec;
        uint16_t data_size;
        struct h_reg *src_reg, *dst_reg;
        uint8_t buf[20];
        const uint8_t *src_buf, *data;
        uint8_t *ptr;
        int i;
        void * (*bin_func)(void *, const void *, size_t);

        if (*code_size < 4)
                return NULL;

        ins = get_unaligned_be32(*ip);
        opcode = **ip;
        data = *ip + 4;
        src_spec = (ins >> 18) & 0x3f;
        dst_spec = (ins >> 12) & 0x3f;
        data_size = (ins & 0x7ff);

        debug("HRE: ins=%08x (op=%02x, s=%02x, d=%02x, L=%d)\n", ins,
              opcode, src_spec, dst_spec, data_size);

        if ((opcode & 0x80) && (data_size + 4) > *code_size)
                return NULL;

        src_reg = access_hreg(src_spec, HREG_RD);
        if (hre_err || hre_tpm_err)
                return NULL;
        dst_reg = access_hreg(dst_spec, (opcode & 0x40) ? HREG_RDWR : HREG_WR);
        if (hre_err || hre_tpm_err)
                return NULL;

        switch (opcode) {
        case HRE_NOP:
                goto end;
        case HRE_CHECK0:
                if (src_reg) {
                        for (i = 0; i < 20; ++i) {
                                if (src_reg->digest[i])
                                        return NULL;
                        }
                }
                break;
        case HRE_LOAD:
                bin_func = memcpy;
                goto do_bin_func;
        case HRE_XOR:
                bin_func = compute_xor;
                goto do_bin_func;
        case HRE_AND:
                bin_func = compute_and;
                goto do_bin_func;
        case HRE_OR:
                bin_func = compute_or;
                goto do_bin_func;
        case HRE_EXTEND:
                bin_func = compute_extend;
do_bin_func:
                if (!dst_reg)
                        return NULL;
                if (src_reg) {
                        src_buf = src_reg->digest;
                } else {
                        if (!data_size) {
                                memset(buf, 0, 20);
                                src_buf = buf;
                        } else if (data_size == 1) {
                                memset(buf, *data, 20);
                                src_buf = buf;
                        } else if (data_size >= 20) {
                                src_buf = data;
                        } else {
                                src_buf = buf;
                                for (ptr = (uint8_t *)src_buf, i = 20; i > 0;
                                        i -= data_size, ptr += data_size)
                                        memcpy(ptr, data,
                                               min_t(size_t, i, data_size));
                        }
                }
                bin_func(dst_reg->digest, src_buf, 20);
                dst_reg->valid = true;
                dst_modified = true;
                break;
        case HRE_LOADKEY:
                if (hre_op_loadkey(src_reg, dst_reg, data, data_size))
                        return NULL;
                break;
        default:
                return NULL;
        }

        if (dst_reg && dst_modified && IS_PCR_HREG(dst_spec)) {
                hre_tpm_err = tpm_extend(HREG_IDX(dst_spec), dst_reg->digest,
                        dst_reg->digest);
                if (hre_tpm_err) {
                        hre_err = HRE_E_TPM_FAILURE;
                        return NULL;
                }
        }
end:
        *ip += 4;
        *code_size -= 4;
        if (opcode & 0x80) {
                *ip += data_size;
                *code_size -= data_size;
        }

        return *ip;
}

/**
 * @brief runs a program on the hash register engine.
 * @param code          pointer to the (HRE) code.
 * @param code_size     size of the code (in bytes).
 * @return 0 on success, != 0 on failure.
 */
static int hre_run_program(const uint8_t *code, size_t code_size)
{
        size_t code_left;
        const uint8_t *ip = code;

        code_left = code_size;
        hre_tpm_err = 0;
        hre_err = HRE_E_OK;
        while (code_left > 0)
                if (!hre_execute_op(&ip, &code_left))
                        return -1;

        return hre_err;
}

static int check_hmac(struct key_program *hmac,
        const uint8_t *data, size_t data_size)
{
        uint8_t key[20], computed_hmac[20];
        uint32_t type;

        type = get_unaligned_be32(hmac->code);
        if (type != 0)
                return 1;
        memset(key, 0, sizeof(key));
        compute_extend(key, pcr_hregs[1].digest, 20);
        compute_extend(key, pcr_hregs[2].digest, 20);
        compute_extend(key, pcr_hregs[3].digest, 20);
        compute_extend(key, pcr_hregs[4].digest, 20);

        sha1_hmac(key, sizeof(key), data, data_size, computed_hmac);

        return memcmp(computed_hmac, hmac->code + 4, 20);
}

static int verify_program(struct key_program *prg)
{
        uint32_t crc;
        crc = crc32(0, prg->code, prg->code_size);

        if (crc != prg->code_crc) {
                printf("HRC crc mismatch: %08x != %08x\n",
                       crc, prg->code_crc);
                return 1;
        }
        return 0;
}

#if defined(CCDM_FIRST_STAGE) || (defined CCDM_AUTO_FIRST_STAGE)
static struct key_program *load_sd_key_program(void)
{
        u32 code_len, code_offset;
        struct mmc *mmc;
        u8 buf[128];
        struct key_program *result = NULL, *hmac = NULL;
        struct key_program header;

        mmc = find_mmc_device(0);
        if (!mmc)
                return NULL;
        mmc_init(mmc);

        if (ccdm_mmc_read(mmc, 0, buf, sizeof(buf)) <= 0)
                goto failure;

        code_offset = *(u32 *)(buf + ESDHC_BOOT_IMAGE_ADDR_OFS);
        code_len = *(u32 *)(buf + ESDHC_BOOT_IMAGE_SIZE_OFS);

        code_offset += code_len;
        /* TODO: the following needs to be the size of the 2nd stage env */
        code_offset += CONFIG_ENV_SIZE;

        if (ccdm_mmc_read(mmc, code_offset, buf, 4*3) < 0)
                goto failure;

        header.magic = get_unaligned_be32(buf);
        header.code_crc = get_unaligned_be32(buf + 4);
        header.code_size = get_unaligned_be32(buf + 8);

        if (header.magic != MAGIC_KEY_PROGRAM)
                goto failure;

        result = malloc(sizeof(struct key_program) + header.code_size);
        if (!result)
                goto failure;
        *result = header;

        printf("load key program chunk from SD card (%u bytes) ",
               header.code_size);
        code_offset += 12;
        if (ccdm_mmc_read(mmc, code_offset, result->code, header.code_size)
                < 0)
                goto failure;
        code_offset += header.code_size;
        puts("\n");

        if (verify_program(result))
                goto failure;

        if (ccdm_mmc_read(mmc, code_offset, buf, 4*3) < 0)
                goto failure;

        header.magic = get_unaligned_be32(buf);
        header.code_crc = get_unaligned_be32(buf + 4);
        header.code_size = get_unaligned_be32(buf + 8);

        if (header.magic == MAGIC_HMAC) {
                puts("check integrity\n");
                hmac = malloc(sizeof(struct key_program) + header.code_size);
                if (!hmac)
                        goto failure;
                *hmac = header;
                code_offset += 12;
                if (ccdm_mmc_read(mmc, code_offset, hmac->code,
                                  hmac->code_size) < 0)
                        goto failure;
                if (verify_program(hmac))
                        goto failure;
                if (check_hmac(hmac, result->code, result->code_size)) {
                        puts("key program integrity could not be verified\n");
                        goto failure;
                }
                puts("key program verified\n");
        }

        goto end;
failure:
        if (result)
                free(result);
        result = NULL;
end:
        if (hmac)
                free(hmac);

        return result;
}
#endif

#ifdef CCDM_SECOND_STAGE
/**
 * @brief load a key program from file system.
 * @param ifname        interface of the file system
 * @param dev_part_str  device part of the file system
 * @param fs_type       tyep of the file system
 * @param path          path of the file to load.
 * @return the loaded structure or NULL on failure.
 */
static struct key_program *load_key_chunk(const char *ifname,
        const char *dev_part_str, int fs_type,
        const char *path)
{
        struct key_program *result = NULL;
        struct key_program header;
        uint32_t crc;
        uint8_t buf[12];
        loff_t i;

        if (fs_set_blk_dev(ifname, dev_part_str, fs_type))
                goto failure;
        if (fs_read(path, (ulong)buf, 0, 12, &i) < 0)
                goto failure;
        if (i < 12)
                goto failure;
        header.magic = get_unaligned_be32(buf);
        header.code_crc = get_unaligned_be32(buf + 4);
        header.code_size = get_unaligned_be32(buf + 8);

        if (header.magic != MAGIC_HMAC && header.magic != MAGIC_KEY_PROGRAM)
                goto failure;

        result = malloc(sizeof(struct key_program) + header.code_size);
        if (!result)
                goto failure;
        if (fs_set_blk_dev(ifname, dev_part_str, fs_type))
                goto failure;
        if (fs_read(path, (ulong)result, 0,
                    sizeof(struct key_program) + header.code_size, &i) < 0)
                goto failure;
        if (i <= 0)
                goto failure;
        *result = header;

        crc = crc32(0, result->code, result->code_size);

        if (crc != result->code_crc) {
                printf("%s: HRC crc mismatch: %08x != %08x\n",
                       path, crc, result->code_crc);
                goto failure;
        }
        goto end;
failure:
        if (result) {
                free(result);
                result = NULL;
        }
end:
        return result;
}
#endif

#if defined(CCDM_FIRST_STAGE) || (defined CCDM_AUTO_FIRST_STAGE)
static int first_stage_actions(void)
{
        int result = 0;
        struct key_program *sd_prg = NULL;

        puts("CCDM S1: start actions\n");
#ifndef CCDM_SECOND_STAGE
        if (tpm_continue_self_test())
                goto failure;
#else
        tpm_continue_self_test();
#endif
        mdelay(37);

        if (hre_run_program(prg_stage1_prepare, sizeof(prg_stage1_prepare)))
                goto failure;

        sd_prg = load_sd_key_program();
        if (sd_prg) {
                if (hre_run_program(sd_prg->code, sd_prg->code_size))
                        goto failure;
                puts("SD code run successfully\n");
        } else {
                puts("no key program found on SD\n");
                goto failure;
        }
        goto end;
failure:
        result = 1;
end:
        if (sd_prg)
                free(sd_prg);
        printf("CCDM S1: actions done (%d)\n", result);
        return result;
}
#endif

#ifdef CCDM_FIRST_STAGE
static int first_stage_init(void)
{
        int res = 0;
        puts("CCDM S1\n");
        if (tpm_init() || tpm_startup(TPM_ST_CLEAR))
                return 1;
        res = first_stage_actions();
#ifndef CCDM_SECOND_STAGE
        if (!res) {
                if (bl2_entry)
                        (*bl2_entry)();
                res = 1;
        }
#endif
        return res;
}
#endif

#ifdef CCDM_SECOND_STAGE
static int second_stage_init(void)
{
        static const char mac_suffix[] = ".mac";
        bool did_first_stage_run = true;
        int result = 0;
        char *cptr, *mmcdev = NULL;
        struct key_program *hmac_blob = NULL;
        const char *image_path = "/ccdm.itb";
        char *mac_path = NULL;
        ulong image_addr;
        loff_t image_size;
        uint32_t err;

        printf("CCDM S2\n");
        if (tpm_init())
                return 1;
        err = tpm_startup(TPM_ST_CLEAR);
        if (err != TPM_INVALID_POSTINIT)
                did_first_stage_run = false;

#ifdef CCDM_AUTO_FIRST_STAGE
        if (!did_first_stage_run && first_stage_actions())
                goto failure;
#else
        if (!did_first_stage_run)
                goto failure;
#endif

        if (hre_run_program(prg_stage2_prepare, sizeof(prg_stage2_prepare)))
                goto failure;

        /* run "prepboot" from env to get "mmcdev" set */
        cptr = getenv("prepboot");
        if (cptr && !run_command(cptr, 0))
                mmcdev = getenv("mmcdev");
        if (!mmcdev)
                goto failure;

        cptr = getenv("ramdiskimage");
        if (cptr)
                image_path = cptr;

        mac_path = malloc(strlen(image_path) + strlen(mac_suffix) + 1);
        if (mac_path == NULL)
                goto failure;
        strcpy(mac_path, image_path);
        strcat(mac_path, mac_suffix);

        /* read image from mmcdev (ccdm.itb) */
        image_addr = (ulong)get_image_location();
        if (fs_set_blk_dev("mmc", mmcdev, FS_TYPE_EXT))
                goto failure;
        if (fs_read(image_path, image_addr, 0, 0, &image_size) < 0)
                goto failure;
        if (image_size <= 0)
                goto failure;
        printf("CCDM image found on %s, %lld bytes\n", mmcdev, image_size);

        hmac_blob = load_key_chunk("mmc", mmcdev, FS_TYPE_EXT, mac_path);
        if (!hmac_blob) {
                puts("failed to load mac file\n");
                goto failure;
        }
        if (verify_program(hmac_blob)) {
                puts("corrupted mac file\n");
                goto failure;
        }
        if (check_hmac(hmac_blob, (u8 *)image_addr, image_size)) {
                puts("image integrity could not be verified\n");
                goto failure;
        }
        puts("CCDM image OK\n");

        hre_run_program(prg_stage2_success, sizeof(prg_stage2_success));

        goto end;
failure:
        result = 1;
        hre_run_program(prg_stage_fail, sizeof(prg_stage_fail));
end:
        if (hmac_blob)
                free(hmac_blob);
        if (mac_path)
                free(mac_path);

        return result;
}
#endif

int show_self_hash(void)
{
        struct h_reg *hash_ptr;
#ifdef CCDM_SECOND_STAGE
        struct h_reg hash;

        hash_ptr = &hash;
        if (compute_self_hash(hash_ptr))
                return 1;
#else
        hash_ptr = &fix_hregs[FIX_HREG_SELF_HASH];
#endif
        puts("self hash: ");
        if (hash_ptr && hash_ptr->valid)
                print_buffer(0, hash_ptr->digest, 1, 20, 20);
        else
                puts("INVALID\n");

        return 0;
}

/**
 * @brief let the system hang.
 *
 * Called on error.
 * Will stop the boot process; display a message and signal the error condition
 * by blinking the "status" and the "finder" LED of the controller board.
 *
 * @note the develop version runs the blink cycle 2 times and then returns.
 * The release version never returns.
 */
static void ccdm_hang(void)
{
        static const u64 f0 = 0x0ba3bb8ba2e880; /* blink code "finder" LED */
        static const u64 s0 = 0x00f0f0f0f0f0f0; /* blink code "status" LED */
        u64 f, s;
        int i;
#ifdef CCDM_DEVELOP
        int j;
#endif

        I2C_SET_BUS(I2C_SOC_0);
        pca9698_direction_output(0x22, 0, 0); /* Finder */
        pca9698_direction_output(0x22, 4, 0); /* Status */

        puts("### ERROR ### Please RESET the board ###\n");
        bootstage_error(BOOTSTAGE_ID_NEED_RESET);
#ifdef CCDM_DEVELOP
        puts("*** ERROR ******** THIS WOULD HANG ******** ERROR ***\n");
        puts("** but we continue since this is a DEVELOP version **\n");
        puts("*** ERROR ******** THIS WOULD HANG ******** ERROR ***\n");
        for (j = 2; j-- > 0;) {
                putc('#');
#else
        for (;;) {
#endif
                f = f0;
                s = s0;
                for (i = 54; i-- > 0;) {
                        pca9698_set_value(0x22, 0, !(f & 1));
                        pca9698_set_value(0x22, 4, (s & 1));
                        f >>= 1;
                        s >>= 1;
                        mdelay(120);
                }
        }
        puts("\ncontinue...\n");
}

int startup_ccdm_id_module(void)
{
        int result = 0;
        unsigned int orig_i2c_bus;

        orig_i2c_bus = i2c_get_bus_num();
        i2c_set_bus_num(I2C_SOC_1);

        /* goto end; */

#ifdef CCDM_DEVELOP
        show_self_hash();
#endif
#ifdef CCDM_FIRST_STAGE
        result = first_stage_init();
        if (result) {
                puts("1st stage init failed\n");
                goto failure;
        }
#endif
#ifdef CCDM_SECOND_STAGE
        result = second_stage_init();
        if (result) {
                puts("2nd stage init failed\n");
                goto failure;
        }
#endif

        goto end;
failure:
        result = 1;
end:
        i2c_set_bus_num(orig_i2c_bus);
        if (result)
                ccdm_hang();

        return result;
}