py/dynruntime.mk: Enable single-precision float by default on armv6/7m.

dpgeorge · dpgeorge · commit 17951cee87d6 · 2025-06-10T13:43:03.000+10:00
Soft float now works on these ARM targets thanks to the parent commit.

Signed-off-by: Damien George &lt;damien@micropython.org&gt;
diff --git a/examples/natmod/random/Makefile b/examples/natmod/random/Makefile
@@ -14,4 +14,9 @@ ifeq ($(ARCH),xtensa)
 MPY_EXTERN_SYM_FILE=$(MPY_DIR)/ports/esp8266/boards/eagle.rom.addr.v6.ld
 endif
 
+ifeq ($(ARCH),$(filter $(ARCH),armv6m armv7m))
+# Link with libm.a for soft-float helper functions
+LINK_RUNTIME = 1
+endif
+
 include $(MPY_DIR)/py/dynruntime.mk
diff --git a/py/dynruntime.mk b/py/dynruntime.mk
@@ -63,14 +63,14 @@ else ifeq ($(ARCH),armv6m)
 # thumb
 CROSS = arm-none-eabi-
 CFLAGS_ARCH += -mthumb -mcpu=cortex-m0
-MICROPY_FLOAT_IMPL ?= none
+MICROPY_FLOAT_IMPL ?= float
 
 else ifeq ($(ARCH),armv7m)
 
 # thumb
 CROSS = arm-none-eabi-
 CFLAGS_ARCH += -mthumb -mcpu=cortex-m3
-MICROPY_FLOAT_IMPL ?= none
+MICROPY_FLOAT_IMPL ?= float
 
 else ifeq ($(ARCH),armv7emsp)
 
diff --git a/tools/ci.sh b/tools/ci.sh
@@ -561,13 +561,11 @@ function ci_native_mpy_modules_build {
         make -C examples/natmod/$natmod ARCH=$arch
     done
 
-    # features2 requires soft-float on armv7m, rv32imc, and xtensa.  On armv6m
-    # the compiler generates absolute relocations in the object file
-    # referencing soft-float functions, which is not supported at the moment.
+    # features2 requires soft-float on rv32imc and xtensa.
     make -C examples/natmod/features2 ARCH=$arch clean
-    if [ $arch = "rv32imc" ] || [ $arch = "armv7m" ] || [ $arch = "xtensa" ]; then
+    if [ $arch = "rv32imc" ] || [ $arch = "xtensa" ]; then
         make -C examples/natmod/features2 ARCH=$arch MICROPY_FLOAT_IMPL=float
-    elif [ $arch != "armv6m" ]; then
+    else
         make -C examples/natmod/features2 ARCH=$arch
     fi
 
