extmod/vfs_blockdev: Add extended read/write methods.

This commit adds helper functions to call readblocks/writeblocks with a
fourth argument, the byte offset within a block.

Although the mp_vfs_blockdev_t struct has grown here by 2 machine words, in
all current uses of this struct within this repository it still fits within
the same number of GC blocks.
This commit is contained in:
Damien George 2019-10-21 19:08:04 +11:00
parent 22bfc47977
commit 98beea9ced
2 changed files with 35 additions and 2 deletions

View File

@ -59,8 +59,8 @@ typedef struct _mp_vfs_proto_t {
typedef struct _mp_vfs_blockdev_t {
uint16_t flags;
size_t block_size;
mp_obj_t readblocks[4];
mp_obj_t writeblocks[4];
mp_obj_t readblocks[5];
mp_obj_t writeblocks[5];
// new protocol uses just ioctl, old uses sync (optional) and count
union {
mp_obj_t ioctl[4];
@ -80,7 +80,9 @@ typedef struct _mp_vfs_mount_t {
void mp_vfs_blockdev_init(mp_vfs_blockdev_t *self, mp_obj_t bdev);
int mp_vfs_blockdev_read(mp_vfs_blockdev_t *self, size_t block_num, size_t num_blocks, uint8_t *buf);
int mp_vfs_blockdev_read_ext(mp_vfs_blockdev_t *self, size_t block_num, size_t block_off, size_t len, uint8_t *buf);
int mp_vfs_blockdev_write(mp_vfs_blockdev_t *self, size_t block_num, size_t num_blocks, const uint8_t *buf);
int mp_vfs_blockdev_write_ext(mp_vfs_blockdev_t *self, size_t block_num, size_t block_off, size_t len, const uint8_t *buf);
mp_obj_t mp_vfs_blockdev_ioctl(mp_vfs_blockdev_t *self, uintptr_t cmd, uintptr_t arg);
mp_vfs_mount_t *mp_vfs_lookup_path(const char *path, const char **path_out);

View File

@ -60,6 +60,19 @@ int mp_vfs_blockdev_read(mp_vfs_blockdev_t *self, size_t block_num, size_t num_b
}
}
int mp_vfs_blockdev_read_ext(mp_vfs_blockdev_t *self, size_t block_num, size_t block_off, size_t len, uint8_t *buf) {
mp_obj_array_t ar = {{&mp_type_bytearray}, BYTEARRAY_TYPECODE, 0, len, buf};
self->readblocks[2] = MP_OBJ_NEW_SMALL_INT(block_num);
self->readblocks[3] = MP_OBJ_FROM_PTR(&ar);
self->readblocks[4] = MP_OBJ_NEW_SMALL_INT(block_off);
mp_obj_t ret = mp_call_method_n_kw(3, 0, self->readblocks);
if (ret == mp_const_none) {
return 0;
} else {
return MP_OBJ_SMALL_INT_VALUE(ret);
}
}
int mp_vfs_blockdev_write(mp_vfs_blockdev_t *self, size_t block_num, size_t num_blocks, const uint8_t *buf) {
if (self->writeblocks[0] == MP_OBJ_NULL) {
// read-only block device
@ -79,6 +92,24 @@ int mp_vfs_blockdev_write(mp_vfs_blockdev_t *self, size_t block_num, size_t num_
}
}
int mp_vfs_blockdev_write_ext(mp_vfs_blockdev_t *self, size_t block_num, size_t block_off, size_t len, const uint8_t *buf) {
if (self->writeblocks[0] == MP_OBJ_NULL) {
// read-only block device
return -MP_EROFS;
}
mp_obj_array_t ar = {{&mp_type_bytearray}, BYTEARRAY_TYPECODE, 0, len, (void*)buf};
self->writeblocks[2] = MP_OBJ_NEW_SMALL_INT(block_num);
self->writeblocks[3] = MP_OBJ_FROM_PTR(&ar);
self->writeblocks[4] = MP_OBJ_NEW_SMALL_INT(block_off);
mp_obj_t ret = mp_call_method_n_kw(3, 0, self->writeblocks);
if (ret == mp_const_none) {
return 0;
} else {
return MP_OBJ_SMALL_INT_VALUE(ret);
}
}
mp_obj_t mp_vfs_blockdev_ioctl(mp_vfs_blockdev_t *self, uintptr_t cmd, uintptr_t arg) {
if (self->flags & MP_BLOCKDEV_FLAG_HAVE_IOCTL) {
// New protocol with ioctl