Add ESP32C3 RISC-V stub
diff --git a/etc/platforms/riscv32/riscv32.jmk b/etc/platforms/riscv32/riscv32.jmk
new file mode 100644
index 0000000..f8249b9
--- /dev/null
+++ b/etc/platforms/riscv32/riscv32.jmk
@@ -0,0 +1,9 @@
+# -*- tcl -*-
+
+set ::ld "clang --target=riscv32"
+set ::cc "clang --target=riscv32"
+set ::asm "clang --target=riscv32"
+
+cflags -mcmodel=medany -march=rv32ima -mabi=ilp32
+asmflags -nostdlib -c
+ldflags $::cflags