diff --git a/src/crypto_stream/chacha/common/armv7m/ref/chacha.jinc b/src/crypto_stream/chacha/common/armv7m/ref/chacha.jinc
new file mode 100644
index 00000000..8af2aae8
--- /dev/null
+++ b/src/crypto_stream/chacha/common/armv7m/ref/chacha.jinc
@@ -0,0 +1,3 @@
+require "chacha_state.jinc"
+require "chacha_store.jinc"
+require "chacha_core.jinc"
diff --git a/src/crypto_stream/chacha/common/armv7m/ref/chacha_core.jinc b/src/crypto_stream/chacha/common/armv7m/ref/chacha_core.jinc
new file mode 100644
index 00000000..a9cc77cc
--- /dev/null
+++ b/src/crypto_stream/chacha/common/armv7m/ref/chacha_core.jinc
@@ -0,0 +1,160 @@
+// the following implementation requires:
+// - (even) param int CHACHA_ROUNDS;
+// - inline fn __init_ref(reg u64 nonce key) -> stack u32[16] (check chacha_state.jinc)
+// - inline fn __increment_counter_ref(stack u32[16] state) -> stack u32[16] (check chacha_state.jinc)
+
+fn _copy_state_ref(reg ptr u32[16] k st) -> reg ptr u32[16]
+{
+  reg u32 i t;
+
+  i = 0;
+  while(i < 16)
+  { t = st[(int)i];
+    k[(int)i] = t;
+    i += 1;
+  }
+
+  return k;
+}
+
+inline fn __line_ref(reg ptr u32[16] k, inline int a b c r) -> reg ptr u32[16]
+{
+  reg u32 ka kb kc;
+
+  ka = k[a];
+  kb = k[b];
+  kc = k[c];
+
+  ka += kb;
+  kc ^= ka;
+  kc = #ROR(kc, (32-r));
+
+  k[a] = ka;
+  k[c] = kc;
+
+  return k;
+}
+
+inline fn __quarter_round_ref(reg ptr u32[16] k, inline int a b c d) -> reg ptr u32[16]
+{
+  k = __line_ref(k, a, b, d, 16);
+  k = __line_ref(k, c, d, b, 12);
+  k = __line_ref(k, a, b, d, 8);
+  k = __line_ref(k, c, d, b, 7);
+  return k;
+}
+
+inline fn __column_round_ref(reg ptr u32[16] k) -> reg ptr u32[16]
+{
+  k = __quarter_round_ref(k, 0, 4,  8, 12);
+  k = __quarter_round_ref(k, 1, 5,  9, 13);
+  k = __quarter_round_ref(k, 2, 6, 10, 14);
+  k = __quarter_round_ref(k, 3, 7, 11, 15);
+  return k;
+}
+
+inline fn __diagonal_round_ref(reg ptr u32[16] k) -> reg ptr u32[16]
+{
+  k = __quarter_round_ref(k, 0, 5, 10, 15);
+  k = __quarter_round_ref(k, 1, 6, 11, 12);
+  k = __quarter_round_ref(k, 2, 7, 8,  13);
+  k = __quarter_round_ref(k, 3, 4, 9,  14);
+  return k;
+}
+
+// TODO: write compact version of this: line_ref args from inline to reg
+inline fn __double_round_ref(reg ptr u32[16] k) -> reg ptr u32[16]
+{
+  k = __column_round_ref(k);
+  k = __diagonal_round_ref(k);
+  return k;
+}
+
+fn _rounds_ref(reg ptr u32[16] k) -> reg ptr u32[16]
+{
+  reg bool zf;
+  reg u32 c;
+
+  c = (CHACHA_ROUNDS/2);
+  while
+  { k = __double_round_ref(k);
+    _, zf, _, _, c = #SUBS(c, 1);
+  } (!zf)
+
+  return k;
+}
+
+fn _sum_states_ref(reg ptr u32[16] k st) -> reg ptr u32[16]
+{
+  reg u32 i tk tst;
+
+  i = 0;
+  while(i < 16)
+  {
+    tk = k[(int)i];
+    tst = st[(int)i];
+    tk += tst;
+    k[(int)i] = tk;
+
+    i += 1;
+  }
+
+  return k;
+}
+
+inline fn __chacha_xor_ref(reg u32 output plain len nonce key)
+{
+  stack u32[16] k st;
+  reg ptr u32[16] kp stp;
+
+  kp = k;
+  stp = st;
+
+  nonce = nonce; // allow register swap
+  key = key; // same.
+
+  stp = _init_ref(stp, nonce, key);
+
+  while (len >= 64)
+  { kp = _copy_state_ref(kp, stp);
+    kp = _rounds_ref(kp);
+    output, plain, len = __sum_states_store_xor_ref(output, plain,len, kp, stp);
+    stp = __increment_counter_ref(stp);
+  }
+
+  if(len > 0)
+  { kp = _copy_state_ref(kp, stp);
+    kp = _rounds_ref(kp);
+    kp = _sum_states_ref(kp, stp);
+    __store_xor_last_ref(output, plain, len, kp);
+  }
+}
+
+inline fn __chacha_ref(reg u32 output len nonce key)
+{
+  stack u32[16] k st;
+  reg ptr u32[16] kp stp;
+
+  kp = k;
+  stp = st;
+
+  nonce = nonce; // allow register swap
+  key = key; // same.
+
+  stp = _init_ref(stp, nonce, key);
+
+  while (len >= 64)
+  { kp = _copy_state_ref(kp, stp);
+    kp = _rounds_ref(kp);
+    output, len = __sum_states_store_ref(output, len, kp, stp);
+    stp = __increment_counter_ref(stp);
+  }
+
+  if(len > 0)
+  { kp = _copy_state_ref(kp, stp);
+    kp = _rounds_ref(kp);
+    kp = _sum_states_ref(kp, stp);
+    __store_last_ref(output, len, kp);
+  }
+}
+
diff --git a/src/crypto_stream/chacha/common/armv7m/ref/chacha_state.jinc b/src/crypto_stream/chacha/common/armv7m/ref/chacha_state.jinc
new file mode 100644
index 00000000..83fd6d74
--- /dev/null
+++ b/src/crypto_stream/chacha/common/armv7m/ref/chacha_state.jinc
@@ -0,0 +1,56 @@
+
+u32[4] CHACHA_SIGMA = { 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574 };
+
+// nonce : 8 bytes
+// key : 32 bytes
+// counter : 8 bytes (starts at 0)
+fn _init_ref(reg ptr u32[16] st, reg u32 nonce key) -> reg ptr u32[16]
+{
+  // TODO: compress this function
+
+  reg ptr u32[4] sigma;
+  reg u32 t;
+  inline int i;
+
+  sigma = CHACHA_SIGMA;
+  for i=0 to 4
+  { t = sigma[i];
+    st[i] = t; }
+
+  // reads 8 u32 from pointer key
+  for i=0 to 8
+  { t = (u32)[key + 4*i];
+    st[4+i] = t; }
+
+  // 64-bit counter
+  t = 0;
+  st[12] = t;
+  st[13] = t;
+
+  // nonce
+  t = (u32)[nonce + 0];
+  st[14] = t;
+  t = (u32)[nonce + 4];
+  st[15] = t;
+
+  return st;
+}
+
+// TODO: double check here: 64 bit counter
+// increments 64-bit counter
+inline fn __increment_counter_ref(reg ptr u32[16] st) -> reg ptr u32[16]
+{
+  reg bool cf;
+  reg u32 l h;
+
+  l = st[12];
+  h = st[13];
+
+  _, _, cf, _, l = #ADDS(l, 1);
+  h = #ADDcc(h, 1, cf, h);
+
+  st[12] = l;
+  st[13] = h;
+
+  return st;
+}
diff --git a/src/crypto_stream/chacha/common/armv7m/ref/chacha_store.jinc b/src/crypto_stream/chacha/common/armv7m/ref/chacha_store.jinc
new file mode 100644
index 00000000..39294c4d
--- /dev/null
+++ b/src/crypto_stream/chacha/common/armv7m/ref/chacha_store.jinc
@@ -0,0 +1,96 @@
+
+// store 'xor' ////////////////////////////////////////////////////////////////
+
+inline fn __update_ptr_xor_ref(reg u32 output plain len, inline int n) -> reg u32, reg u32, reg u32
+{
+  output += n;
+  plain += n;
+  len -= n;
+  return output, plain, len;
+}
+
+inline fn __sum_states_store_xor_ref(
+  reg u32 output plain len,
+  reg ptr u32[16] k st)
+  ->
+  reg u32, reg u32, reg u32
+{
+  reg u32 i t s v;
+
+  i = 0;
+  while(i < 16)
+  { t = k[(int)i];
+    s = st[(int)i];
+    v = (u32)[plain + 4*i];
+    t += s;
+    t ^= v;
+    (u32)[output + 4*i] = t;
+    i += 1;
+  }
+
+  output, plain, len = __update_ptr_xor_ref(output, plain, len, 64);
+
+  return output, plain, len;
+}
+
+
+// len bytes
+inline fn __store_xor_last_ref(reg u32 output plain len, reg ptr u32[16] k)
+{
+  reg u32 i t v;
+
+  i = 0;
+  while(i < len)
+  { t = (32u)k[u8 (int)i];
+    v = (32u)(u8)[plain + i];
+    t ^= v;
+    (u8)[output + i] = t;
+    i += 1;
+  }
+}
+
+// store //////////////////////////////////////////////////////////////////////
+
+inline fn __update_ptr_ref(reg u32 output len, inline int n) -> reg u32, reg u32
+{
+  output += n;
+  len -= n;
+  return output, len;
+}
+
+inline fn __sum_states_store_ref(
+  reg u32 output len,
+  reg ptr u32[16] k st)
+  ->
+  reg u32, reg u32
+{
+  reg u32 i t s;
+
+  i = 0;
+  while(i < 16)
+  { t = k[(int)i];
+    s = st[(int)i];
+    t += s;
+    [output + 4*i] = t;
+    i += 1;
+  }
+
+  output, len = __update_ptr_ref(output, len, 64);
+
+  return output, len;
+}
+
+// len bytes
+inline fn __store_last_ref(reg u32 output len, reg ptr u32[16] k)
+{
+  reg u32 i t;
+
+  i = 0;
+  while(i < len)
+  { t = (32u)k[u8 (int)i];
+    (u8)[output + i] = t;
+    i += 1;
+  }
+}
+
+