it's called firmware.ELF thank you very much

Makefile

@@ -5,15 +5,16 @@ MAKEFLAGS += --no-builtin-variables
 BUILD_FLAGS = --release-small -target thumbv7m-freestanding-none
 LINKER_SCRIPT = arm_cm3.ld
 OBJS = startup.o main.o
+PROG = firmware
 
 %.o: %.zig
  zig build-obj ${BUILD_FLAGS} $<
 
-firmware: ${OBJS}
-# zig build-exe ${BUILD_FLAGS} $(OBJS:%=--object %) --name $@ --linker-script ${LINKER_SCRIPT}
- arm-none-eabi-ld ${OBJS} -o $@ -T ${LINKER_SCRIPT} -Map [email protected] --gc-sections
+${PROG}: ${OBJS}
+# zig build-exe ${BUILD_FLAGS} $(OBJS:%=--object %) --name $@.elf --linker-script ${LINKER_SCRIPT}
+ arm-none-eabi-ld ${OBJS} -o $@.elf -T ${LINKER_SCRIPT} -Map [email protected] --gc-sections
 
 clean:
- rm -rf firmware firmware.map ${OBJS} $(OBJS:%.o=%.h) zig-cache
+ rm -rf ${PROG}.* ${OBJS} $(OBJS:%.o=%.h) zig-cache
 
 .PHONY: clean

build.zig

@@ -4,7 +4,7 @@ const builtin = @import("builtin");
 pub fn build(b: *Builder) void {
  const mode = b.standardReleaseOptions();
 
- const exe = b.addExecutable("firmware", "main.zig");
+ const exe = b.addExecutable("firmware.elf", "main.zig");
  exe.setTarget(builtin.Arch { .thumb = .v7m }, builtin.Os.freestanding, builtin.Abi.none);
 
  const main_o = b.addObject("startup", "startup.zig");