stmhal: Implement sys.std{in,out,err}.buffer, for raw byte mode.

It's configurable and only enabled for stmhal port.

py/mpconfig.h

@@ -594,6 +594,11 @@ typedef double mp_float_t;
 #define MICROPY_PY_SYS_STDFILES (0)
 #endif
 
+// Whether to provide sys.{stdin,stdout,stderr}.buffer object
+// This is implemented per-port
+#ifndef MICROPY_PY_SYS_STDIO_BUFFER
+#define MICROPY_PY_SYS_STDIO_BUFFER (0)
+#endif
 
 // Extended modules
 

py/qstrdefs.h

@@ -448,6 +448,9 @@ Q(platform)
 Q(stdin)
 Q(stdout)
 Q(stderr)
+#if MICROPY_PY_SYS_STDIO_BUFFER
+Q(buffer)
+#endif
 Q(version)
 Q(version_info)
 #if MICROPY_PY_ATTRTUPLE

stmhal/mpconfigport.h

@@ -66,6 +66,7 @@
 #define MICROPY_PY_SYS_EXIT         (1)
 #define MICROPY_PY_SYS_MAXSIZE      (1)
 #define MICROPY_PY_SYS_STDFILES     (1)
+#define MICROPY_PY_SYS_STDIO_BUFFER (1)
 #define MICROPY_PY_COLLECTIONS_ORDEREDDICT (1)
 #define MICROPY_PY_MATH_SPECIAL_FUNCTIONS (1)
 #define MICROPY_PY_CMATH            (1)

stmhal/pybstdio.c

@@ -48,6 +48,10 @@ typedef struct _pyb_stdio_obj_t {
     int fd;
 } pyb_stdio_obj_t;
 
+#if MICROPY_PY_SYS_STDIO_BUFFER
+STATIC const pyb_stdio_obj_t stdio_buffer_obj;
+#endif
+
 void stdio_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     pyb_stdio_obj_t *self = self_in;
     mp_printf(print, "<io.FileIO %d>", self->fd);
@@ -89,6 +93,9 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(stdio_obj___exit___obj, 4, 4, stdio_o
 // TODO gc hook to close the file if not already closed
 
 STATIC const mp_map_elem_t stdio_locals_dict_table[] = {
+#if MICROPY_PY_SYS_STDIO_BUFFER
+    { MP_OBJ_NEW_QSTR(MP_QSTR_buffer), (mp_obj_t)&stdio_buffer_obj },
+#endif
     { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&mp_stream_read_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_readall), (mp_obj_t)&mp_stream_readall_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_readinto), (mp_obj_t)&mp_stream_readinto_obj },
@@ -123,3 +130,35 @@ STATIC const mp_obj_type_t stdio_obj_type = {
 const pyb_stdio_obj_t mp_sys_stdin_obj = {{&stdio_obj_type}, .fd = STDIO_FD_IN};
 const pyb_stdio_obj_t mp_sys_stdout_obj = {{&stdio_obj_type}, .fd = STDIO_FD_OUT};
 const pyb_stdio_obj_t mp_sys_stderr_obj = {{&stdio_obj_type}, .fd = STDIO_FD_ERR};
+
+#if MICROPY_PY_SYS_STDIO_BUFFER
+STATIC mp_uint_t stdio_buffer_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode) {
+    for (uint i = 0; i < size; i++) {
+        ((byte*)buf)[i] = mp_hal_stdin_rx_chr();
+    }
+    return size;
+}
+
+STATIC mp_uint_t stdio_buffer_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
+    mp_hal_stdout_tx_strn(buf, size);
+    return size;
+}
+
+STATIC const mp_stream_p_t stdio_buffer_obj_stream_p = {
+    .read = stdio_buffer_read,
+    .write = stdio_buffer_write,
+    .is_text = false,
+};
+
+STATIC const mp_obj_type_t stdio_buffer_obj_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_FileIO,
+    .print = stdio_obj_print,
+    .getiter = mp_identity,
+    .iternext = mp_stream_unbuffered_iter,
+    .stream_p = &stdio_buffer_obj_stream_p,
+    .locals_dict = (mp_obj_t)&stdio_locals_dict,
+};
+
+STATIC const pyb_stdio_obj_t stdio_buffer_obj = {{&stdio_buffer_obj_type}, .fd = 0}; // fd unused
+#endif