nCodeSlots    uint32 // number of ordinary (code) hash slots
	codeLimit     uint32 // limit to main image signature range
	hashSize      uint8  // size of each hash in bytes
	hashType      uint8  // type of hash (cdHashType* constants)
	_pad1         uint8  // unused (must be zero)
	pageSize      uint8  // log2(page size in bytes); 0 => infinite
	_pad2         uint32 // unused (must be zero)

	r = Addrel(syms[4])
	r.Sym = syms[0]
	// s5 references s1
	r = Addrel(syms[5])
	r.Sym = syms[1]
	// s6 references s2
	r = Addrel(syms[6])
	r.Sym = syms[2]

	// compute hashes
	h := make([]goobj.HashType, len(syms))
	w := &writer{}
	for i := range h {
		h[i] = w.contentHash(syms[i])
	}

	tests := []struct {
		a, b  int
		equal bool
	}{
		{0, 1, true},  // same contents, no relocs

	// scratch space for writing (the Write methods escape
	// as they are interface calls)
	tmpSym      goobj.Sym
	tmpReloc    goobj.Reloc
	tmpAux      goobj.Aux
	tmpHash64   goobj.Hash64Type
	tmpHash     goobj.HashType
	tmpRefFlags goobj.RefFlags
	tmpRefName  goobj.RefName
}

// prepare package index list
func (w *writer) init() {
	w.pkglist = make([]string, len(w.ctxt.pkgIdx)+1)

// Hash returns a pointer to the i-th hashed symbol's hash.
// Note: here i is the index of hashed symbols, not all symbols
// (unlike other accessors).
func (r *Reader) Hash(i uint32) *HashType {
	off := r.h.Offsets[BlkHash] + uint32(i*HashSize)
	return (*HashType)(unsafe.Pointer(&r.b[off]))
}

// NReloc returns the number of relocations of the i-th symbol.
func (r *Reader) NReloc(i uint32) int {

	var hashType crypto.Hash
	var pubKeyAlgo PublicKeyAlgorithm

	for _, details := range signatureAlgorithmDetails {
		if details.algo == algo {
			hashType = details.hash
			pubKeyAlgo = details.pubKeyAlgo
			break
		}
	}

	switch hashType {
	case crypto.Hash(0):
		if pubKeyAlgo != Ed25519 {
			return ErrUnsupportedAlgorithm

		// check, as same hash indicates same content.
		var checkHash func() (symAndSize, bool)
		var addToHashMap func(symAndSize)
		var h64 uint64        // only used for hashed64Def
		var h *goobj.HashType // only used for hashedDef
		if kind == hashed64Def {
			checkHash = func() (symAndSize, bool) {
				h64 = r.Hash64(li - uint32(r.ndef))
				s, existed := st.hashed64Syms[h64]
				return s, existed
			}