stm32/boards/LEGO_HUB_NO6: Use a raw filesystem for mboot to update fw.

The C-based SPI flash driver is needed because the
`_copy_file_to_raw_filesystem()` function must copy from a filesystem (eg
FAT) to another part of flash, and the same C code must be used for both
reading (from FAT) and writing (to flash).

Signed-off-by: Damien George <damien@micropython.org>

4 files changed, 212 insertions, 115 deletions

diff --git a/ports/stm32/boards/LEGO_HUB_NO6/appupdate.py b/ports/stm32/boards/LEGO_HUB_NO6/appupdate.py
index 9cfbc06e5..8229004fb 100644
--- a/ports/stm32/boards/LEGO_HUB_NO6/appupdate.py
+++ b/ports/stm32/boards/LEGO_HUB_NO6/appupdate.py
@@ -1,39 +1,61 @@
 # Application firmware update function for LEGO_HUB_NO6.
-# MIT license; Copyright (c) 2022 Damien P. George
+# MIT license; Copyright (c) 2022-2024 Damien P. George
 
 from micropython import const
-import struct, machine, fwupdate, spiflash, pyb
+import random, struct, machine, fwupdate, spiflash, pyb
 
 _IOCTL_BLOCK_COUNT = const(4)
 _IOCTL_BLOCK_SIZE = const(5)
 
-_FILESYSTEM_ADDR = const(0x8000_0000 + 1024 * 1024)
-
-# Roundabout way to get actual filesystem size from config.
-# This takes into account the 1M "reserved" section of the flash memory.
-flash = pyb.Flash(start=0)
-_FILESYSTEM_LEN = flash.ioctl(_IOCTL_BLOCK_COUNT, None) * flash.ioctl(_IOCTL_BLOCK_SIZE, None)
+# Mboot addresses the external SPI flash at this location.
+_MBOOT_SPIFLASH_BASE_ADDR = 0x80000000
+
+# The raw filesystem is in the first 1MiB of external SPI flash,
+# but skip the first and last flash sectors.
+_RAW_FILESYSTEM_ADDR = const(4 * 1024)
+_RAW_FILESYSTEM_LEN = const(1016 * 1024)
+
+
+def _copy_file_to_raw_filesystem(filename, flash, block):
+    block_count = flash.ioctl(_IOCTL_BLOCK_COUNT, 0)
+    block_size = flash.ioctl(_IOCTL_BLOCK_SIZE, 0)
+    buf = bytearray(block_size)
+    with open(filename, "rb") as file:
+        while True:
+            n = file.readinto(buf)
+            if not n:
+                break
+            flash.writeblocks(block, buf)
+            block += 1
+            if block >= block_count:
+                print("|", end="")
+                block = 0
+            print(".", end="")
+    print()
 
 
 def update_app(filename):
     print(f"Updating application firmware from {filename}")
 
-    # Create the elements for the mboot filesystem-load operation.
-    elems = fwupdate.update_app_elements(filename, _FILESYSTEM_ADDR, _FILESYSTEM_LEN)
-    if not elems:
-        return
-
-    # Create a SPI flash object.
-    spi = machine.SoftSPI(
-        sck=machine.Pin.board.FLASH_SCK,
-        mosi=machine.Pin.board.FLASH_MOSI,
-        miso=machine.Pin.board.FLASH_MISO,
-        baudrate=50_000_000,
-    )
-    cs = machine.Pin(machine.Pin.board.FLASH_NSS, machine.Pin.OUT, value=1)
-
     # We can't use pyb.Flash() because we need to write to the "reserved" 1M area.
-    flash = spiflash.SPIFlash(spi, cs)
+    flash = spiflash.SPIFlash(start=_RAW_FILESYSTEM_ADDR, len=_RAW_FILESYSTEM_LEN)
+
+    # Partition the raw filesystem into two segments for wear levelling.
+    block_count = flash.ioctl(_IOCTL_BLOCK_COUNT, 0)
+    block_size = flash.ioctl(_IOCTL_BLOCK_SIZE, 0)
+    block_start = random.randrange(0, block_count)
+    print(f"Raw filesystem block layout: 0 .. {block_start} .. {block_count}")
+
+    # Copy the file to the special raw filesystem.
+    _copy_file_to_raw_filesystem(filename, flash, block_start)
 
     # Enter mboot with a request to do a filesystem-load update.
-    machine.bootloader(elems)
+    # Note: the filename doesn't mean anything here, but still needs to be non-empty.
+    fwupdate.update_mpy(
+        filename,
+        fs_type=fwupdate.VFS_RAW,
+        fs_base=_MBOOT_SPIFLASH_BASE_ADDR + _RAW_FILESYSTEM_ADDR + block_start * block_size,
+        fs_len=(block_count - block_start) * block_size,
+        fs_base2=_MBOOT_SPIFLASH_BASE_ADDR + _RAW_FILESYSTEM_ADDR,
+        fs_len2=block_start * block_size,
+    )
diff --git a/ports/stm32/boards/LEGO_HUB_NO6/manifest.py b/ports/stm32/boards/LEGO_HUB_NO6/manifest.py
index 1be4246e3..afbfdc0a8 100644
--- a/ports/stm32/boards/LEGO_HUB_NO6/manifest.py
+++ b/ports/stm32/boards/LEGO_HUB_NO6/manifest.py
@@ -4,5 +4,4 @@ include("$(PORT_DIR)/boards/manifest.py")
 
 # Modules for application firmware update.
 module("fwupdate.py", base_path="$(PORT_DIR)/mboot", opt=3)
-module("spiflash.py", opt=3)
 module("appupdate.py", opt=3)
diff --git a/ports/stm32/boards/LEGO_HUB_NO6/spiflash.c b/ports/stm32/boards/LEGO_HUB_NO6/spiflash.c
new file mode 100644
index 000000000..37df7c953
--- /dev/null
+++ b/ports/stm32/boards/LEGO_HUB_NO6/spiflash.c
@@ -0,0 +1,166 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2024 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#if !BUILDING_MBOOT
+
+#include "py/runtime.h"
+#include "extmod/vfs.h"
+
+#include "storage.h"
+
+// Expose the entire external SPI flash as an object with the block protocol.
+
+#define FLASH_SIZE (MICROPY_HW_SPIFLASH_OFFSET_BYTES + MICROPY_HW_SPIFLASH_SIZE_BITS / 8)
+#define BLOCK_SIZE (4096)
+
+typedef struct _spi_flash_obj_t {
+    mp_obj_base_t base;
+    uint32_t start; // in bytes
+    uint32_t len; // in bytes
+} spi_flash_obj_t;
+
+static const mp_obj_type_t spi_flash_type;
+
+static void spi_flash_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    spi_flash_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_printf(print, "SPIFlash(start=%u, len=%u)", self->start, self->len);
+}
+
+static mp_obj_t spi_flash_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    enum { ARG_start, ARG_len };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_len,   MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    spi_flash_obj_t *self = mp_obj_malloc(spi_flash_obj_t, &spi_flash_type);
+
+    mp_int_t start = args[ARG_start].u_int;
+    if (!(0 <= start && start < FLASH_SIZE && start % BLOCK_SIZE == 0)) {
+        mp_raise_ValueError(NULL);
+    }
+
+    mp_int_t len = args[ARG_len].u_int;
+    if (len == -1) {
+        len = FLASH_SIZE - start;
+    } else if (!(0 < len && start + len <= FLASH_SIZE && len % BLOCK_SIZE == 0)) {
+        mp_raise_ValueError(NULL);
+    }
+
+    self->start = start;
+    self->len = len;
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+static mp_obj_t spi_flash_readblocks(size_t n_args, const mp_obj_t *args) {
+    spi_flash_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    uint32_t block_num = self->start / BLOCK_SIZE + mp_obj_get_int(args[1]);
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_WRITE);
+    int ret = spi_bdev_readblocks_raw(&spi_bdev, bufinfo.buf, block_num, 0, bufinfo.len);
+    return MP_OBJ_NEW_SMALL_INT(ret);
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(spi_flash_readblocks_obj, 3, 3, spi_flash_readblocks);
+
+static mp_obj_t spi_flash_writeblocks(size_t n_args, const mp_obj_t *args) {
+    spi_flash_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    uint32_t block_num = self->start / BLOCK_SIZE + mp_obj_get_int(args[1]);
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_READ);
+    int ret = spi_bdev_eraseblocks_raw(&spi_bdev, block_num, bufinfo.len);
+    if (ret == 0) {
+        ret = spi_bdev_writeblocks_raw(&spi_bdev, bufinfo.buf, block_num, 0, bufinfo.len);
+    }
+    return MP_OBJ_NEW_SMALL_INT(ret);
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(spi_flash_writeblocks_obj, 3, 3, spi_flash_writeblocks);
+
+static mp_obj_t spi_flash_ioctl(mp_obj_t self_in, mp_obj_t cmd_in, mp_obj_t arg_in) {
+    spi_flash_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    mp_int_t cmd = mp_obj_get_int(cmd_in);
+    switch (cmd) {
+        case MP_BLOCKDEV_IOCTL_INIT:
+            storage_init();
+            return MP_OBJ_NEW_SMALL_INT(0);
+
+        case MP_BLOCKDEV_IOCTL_DEINIT:
+            return MP_OBJ_NEW_SMALL_INT(0);
+
+        case MP_BLOCKDEV_IOCTL_SYNC:
+            return MP_OBJ_NEW_SMALL_INT(0);
+
+        case MP_BLOCKDEV_IOCTL_BLOCK_COUNT: {
+            mp_int_t n = self->len / BLOCK_SIZE;
+            return MP_OBJ_NEW_SMALL_INT(n);
+        }
+
+        case MP_BLOCKDEV_IOCTL_BLOCK_SIZE:
+            return MP_OBJ_NEW_SMALL_INT(BLOCK_SIZE);
+
+        default:
+            return mp_const_none;
+    }
+}
+static MP_DEFINE_CONST_FUN_OBJ_3(spi_flash_ioctl_obj, spi_flash_ioctl);
+
+static const mp_rom_map_elem_t spi_flash_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_readblocks), MP_ROM_PTR(&spi_flash_readblocks_obj) },
+    { MP_ROM_QSTR(MP_QSTR_writeblocks), MP_ROM_PTR(&spi_flash_writeblocks_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ioctl), MP_ROM_PTR(&spi_flash_ioctl_obj) },
+};
+static MP_DEFINE_CONST_DICT(spi_flash_locals_dict, spi_flash_locals_dict_table);
+
+static MP_DEFINE_CONST_OBJ_TYPE(
+    spi_flash_type,
+    MP_QSTR_SPIFlash,
+    MP_TYPE_FLAG_NONE,
+    make_new, spi_flash_make_new,
+    print, spi_flash_print,
+    locals_dict, &spi_flash_locals_dict
+    );
+
+/******************************************************************************/
+// The `spiflash` module.
+
+static const mp_rom_map_elem_t spiflash_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_spiflash) },
+
+    { MP_ROM_QSTR(MP_QSTR_SPIFlash), MP_ROM_PTR(&spi_flash_type) },
+};
+static MP_DEFINE_CONST_DICT(spiflash_module_globals, spiflash_module_globals_table);
+
+const mp_obj_module_t spiflash_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&spiflash_module_globals,
+};
+
+MP_REGISTER_MODULE(MP_QSTR_spiflash, spiflash_module);
+
+#endif
diff --git a/ports/stm32/boards/LEGO_HUB_NO6/spiflash.py b/ports/stm32/boards/LEGO_HUB_NO6/spiflash.py
deleted file mode 100644
index e483ace95..000000000
--- a/ports/stm32/boards/LEGO_HUB_NO6/spiflash.py
+++ /dev/null
@@ -1,90 +0,0 @@
-# MicroPython driver for SPI flash
-# MIT license; Copyright (c) 2022 Damien P. George
-
-from micropython import const
-
-_PAGE_SIZE = const(256)  # maximum bytes writable in one SPI transfer
-_CMD_WRITE = const(0x02)
-_CMD_READ = const(0x03)
-_CMD_RDSR = const(0x05)
-_CMD_WREN = const(0x06)
-_CMD_WRITE_32 = const(0x12)
-_CMD_READ_32 = const(0x13)
-_CMD_SEC_ERASE = const(0x20)
-_CMD_SEC_ERASE_32 = const(0x21)
-_CMD_JEDEC_ID = const(0x9F)
-
-
-class SPIFlash:
-    def __init__(self, spi, cs):
-        self.spi = spi
-        self.cs = cs
-        self.id = self._get_id()
-        # flash chip on Hub No. 6 uses 32-bit addressing
-        _32_bit = self.id == b"\xef\x40\x19"
-        self._READ = _CMD_READ_32 if _32_bit else _CMD_READ
-        self._WRITE = _CMD_WRITE_32 if _32_bit else _CMD_WRITE
-        self._ERASE = _CMD_SEC_ERASE_32 if _32_bit else _CMD_SEC_ERASE
-
-    def _get_id(self):
-        self.cs(0)
-        self.spi.write(bytearray([_CMD_JEDEC_ID]))
-        buf = self.spi.read(3)
-        self.cs(1)
-        return buf
-
-    def _wait_wel1(self):
-        # wait WEL=1
-        self.cs(0)
-        self.spi.write(bytearray([_CMD_RDSR]))
-        buf = bytearray(1)
-        while True:
-            self.spi.readinto(buf)
-            if buf[0] & 2:
-                break
-        self.cs(1)
-
-    def _wait_wip0(self):
-        # wait WIP=0
-        self.cs(0)
-        self.spi.write(bytearray([_CMD_RDSR]))
-        buf = bytearray(1)
-        while True:
-            self.spi.readinto(buf)
-            if not (buf[0] & 1):
-                break
-        self.cs(1)
-
-    def _flash_modify(self, cmd, addr, buf):
-        self.cs(0)
-        self.spi.write(bytearray([_CMD_WREN]))
-        self.cs(1)
-        self._wait_wel1()
-        self.cs(0)
-        self.spi.write(bytearray([cmd, addr >> 24, addr >> 16, addr >> 8, addr]))
-        if buf:
-            self.spi.write(buf)
-        self.cs(1)
-        self._wait_wip0()
-
-    def erase_block(self, addr):
-        self._flash_modify(self._ERASE, addr, None)
-
-    def readinto(self, addr, buf):
-        self.cs(0)
-        self.spi.write(bytearray([self._READ, addr >> 16, addr >> 8, addr]))
-        self.spi.readinto(buf)
-        self.cs(1)
-
-    def write(self, addr, buf):
-        offset = addr & (_PAGE_SIZE - 1)
-        remain = len(buf)
-        buf = memoryview(buf)
-        buf_offset = 0
-        while remain:
-            l = min(_PAGE_SIZE - offset, remain)
-            self._flash_modify(self._WRITE, addr, buf[buf_offset : buf_offset + l])
-            remain -= l
-            addr += l
-            buf_offset += l
-            offset = 0