1 files changed, 94 insertions, 0 deletions
diff --git a/stmhal/file.c b/stmhal/file.c
new file mode 100644
index 0000000000..83bb6013fc
--- /dev/null
+++ b/stmhal/file.c
@@ -0,0 +1,94 @@
+#include <stdio.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "file.h"
+#include "ff.h"
+
+typedef struct _pyb_file_obj_t {
+    mp_obj_base_t base;
+    FIL fp;
+} pyb_file_obj_t;
+
+void file_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+    printf("<file %p>", self_in);
+}
+
+mp_obj_t file_obj_read(mp_obj_t self_in, mp_obj_t arg) {
+    pyb_file_obj_t *self = self_in;
+    int n = mp_obj_get_int(arg);
+    byte *buf = m_new(byte, n);
+    UINT n_out;
+    f_read(&self->fp, buf, n, &n_out);
+    return mp_obj_new_str(buf, n_out, false);
+}
+
+mp_obj_t file_obj_write(mp_obj_t self_in, mp_obj_t arg) {
+    pyb_file_obj_t *self = self_in;
+    uint l;
+    const char *s = mp_obj_str_get_data(arg, &l);
+    UINT n_out;
+    FRESULT res = f_write(&self->fp, s, l, &n_out);
+    if (res != FR_OK) {
+        printf("File error: could not write to file; error code %d\n", res);
+    } else if (n_out != l) {
+        printf("File error: could not write all data to file; wrote %d / %d bytes\n", n_out, l);
+    }
+    return mp_const_none;
+}
+
+mp_obj_t file_obj_close(mp_obj_t self_in) {
+    pyb_file_obj_t *self = self_in;
+    f_close(&self->fp);
+    return mp_const_none;
+}
+
+static MP_DEFINE_CONST_FUN_OBJ_2(file_obj_read_obj, file_obj_read);
+static MP_DEFINE_CONST_FUN_OBJ_2(file_obj_write_obj, file_obj_write);
+static MP_DEFINE_CONST_FUN_OBJ_1(file_obj_close_obj, file_obj_close);
+
+// TODO gc hook to close the file if not already closed
+
+static const mp_method_t file_methods[] = {
+    { "read", &file_obj_read_obj },
+    { "write", &file_obj_write_obj },
+    { "close", &file_obj_close_obj },
+    {NULL, NULL},
+};
+
+static const mp_obj_type_t file_obj_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_File,
+    .print = file_obj_print,
+    .methods = file_methods,
+};
+
+STATIC mp_obj_t pyb_io_open(mp_obj_t o_filename, mp_obj_t o_mode) {
+    const char *filename = mp_obj_str_get_str(o_filename);
+    const char *mode = mp_obj_str_get_str(o_mode);
+    pyb_file_obj_t *self = m_new_obj(pyb_file_obj_t);
+    self->base.type = &file_obj_type;
+    if (mode[0] == 'r') {
+        // open for reading
+        FRESULT res = f_open(&self->fp, filename, FA_READ);
+        if (res != FR_OK) {
+            printf("FileNotFoundError: [Errno 2] No such file or directory: '%s'\n", filename);
+            return mp_const_none;
+        }
+    } else if (mode[0] == 'w') {
+        // open for writing, truncate the file first
+        FRESULT res = f_open(&self->fp, filename, FA_WRITE | FA_CREATE_ALWAYS);
+        if (res != FR_OK) {
+            printf("?FileError: could not create file: '%s'\n", filename);
+            return mp_const_none;
+        }
+    } else {
+        printf("ValueError: invalid mode: '%s'\n", mode);
+        return mp_const_none;
+    }
+    return self;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_open_obj, pyb_io_open);