py/emitinlinerv32: Add inline assembler support for RV32.

This commit adds support for writing inline assembler functions when
targeting a RV32IMC processor.

Given that this takes up a bit of rodata space due to its large
instruction decoding table and its extensive error messages, it is
enabled by default only on offline targets such as mpy-cross and the
qemu port.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

1 files changed, 59 insertions, 0 deletions

diff --git a/tests/inlineasm/rv32/asmsum.py b/tests/inlineasm/rv32/asmsum.py
new file mode 100644
index 000000000..5d805553b
--- /dev/null
+++ b/tests/inlineasm/rv32/asmsum.py
@@ -0,0 +1,59 @@
+@micropython.asm_rv32
+def asm_sum_words(a0, a1):
+    # a0 = len
+    # a1 = ptr
+    # a2 = sum
+    # a3 = dummy
+    li(a2, 0)
+
+    jal(zero, loop_entry)
+
+    label(loop1)
+    lw(a3, 0(a1))
+    add(a2, a2, a3)
+
+    addi(a1, a1, 4)
+    addi(a0, a0, -1)
+
+    label(loop_entry)
+    bne(a0, zero, loop1)
+
+    mv(a0, a2)
+
+
+@micropython.asm_rv32
+def asm_sum_bytes(a0, a1):
+    # a0 = len
+    # a1 = ptr
+    # a2 = sum
+    # a3 = dummy
+    li(a2, 0)
+
+    jal(zero, loop_entry)
+
+    label(loop1)
+    lbu(a3, 0(a1))
+    add(a2, a2, a3)
+
+    addi(a1, a1, 1)
+    addi(a0, a0, -1)
+
+    label(loop_entry)
+    bne(a0, zero, loop1)
+
+    mv(a0, a2)
+
+
+import array
+
+b = array.array("l", (100, 200, 300, 400))
+n = asm_sum_words(len(b), b)
+print(b, n)
+
+b = array.array("b", (10, 20, 30, 40, 50, 60, 70, 80))
+n = asm_sum_bytes(len(b), b)
+print(b, n)
+
+b = b"\x01\x02\x03\x04"
+n = asm_sum_bytes(len(b), b)
+print(b, n)