esp8266: Add board variant support.

This merges the existing GENERIC, GENERIC_1M, and GENERIC_512k boards
into variants of the new ESP8266_GENERIC board (renamed from GENERIC so
as not to clash with other ports).

Also moves the generation of the "OTA" variant (previously generated by
autobuild/build-esp8266-latest.sh) into the variant.

Following the convention established for the WEACTSTUDIO rp2 board, the
names of the variants are FLASH_1M and FLASH_512K (but rename the .ld files
to use MiB and kiB).

Updates autobuild to build esp8266 firmware the same way as other ports.
This requires renaming the output from firmware-combined.bin to just
firmware.bin.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

ports/esp8266/Makefile

@@ -4,17 +4,25 @@ ifdef BOARD_DIR
 # the path as the board name.
 BOARD ?= $(notdir $(BOARD_DIR:/=))
 else
-# If not given on the command line, then default to GENERIC.
-BOARD ?= GENERIC
+# If not given on the command line, then default to ESP8266_GENERIC.
+BOARD ?= ESP8266_GENERIC
 BOARD_DIR ?= boards/$(BOARD)
 endif
 
 ifeq ($(wildcard $(BOARD_DIR)/.),)
+ifeq ($(findstring boards/GENERIC,$(BOARD_DIR)),boards/GENERIC)
+$(warning The GENERIC* boards have been renamed to ESP8266_GENERIC)
+endif
 $(error Invalid BOARD specified: $(BOARD_DIR))
 endif
 
-# If the build directory is not given, make it reflect the board name.
+# If the build directory is not given, make it reflect the board name (and
+# optionally the board variant).
+ifneq ($(BOARD_VARIANT),)
+BUILD ?= build-$(BOARD)-$(BOARD_VARIANT)
+else
 BUILD ?= build-$(BOARD)
+endif
 
 include ../../py/mkenv.mk
 
@@ -40,7 +48,7 @@ include $(TOP)/extmod/extmod.mk
 
 GIT_SUBMODULES += lib/axtls lib/berkeley-db-1.xx
 
-FWBIN = $(BUILD)/firmware-combined.bin
+FWBIN = $(BUILD)/firmware.bin
 PORT ?= /dev/ttyACM0
 BAUD ?= 115200
 FLASH_MODE ?= qio
@@ -202,7 +210,7 @@ FROZEN_EXTRA_DEPS = $(CONFVARS_FILE)
 
 .PHONY: deploy
 
-deploy: $(BUILD)/firmware-combined.bin
+deploy: $(FWBIN)
 	$(ECHO) "Writing $< to the board"
 	$(Q)esptool.py --port $(PORT) --baud $(BAUD) write_flash --verify --flash_size=$(FLASH_SIZE) --flash_mode=$(FLASH_MODE) 0 $<
 
@@ -213,20 +221,26 @@ erase:
 reset:
 	echo -e "\r\nimport machine; machine.reset()\r\n" >$(PORT)
 
+ifeq ($(BOARD_VARIANT),OTA)
+$(FWBIN): $(BUILD)/firmware.elf
+	$(ECHO) "Create $@"
+	$(Q)esptool.py elf2image $^
+	$(Q)$(PYTHON) makeimg.py $(BUILD)/firmware.elf-0x00000.bin $(BUILD)/firmware.elf-0x[0-5][1-f]000.bin $(BUILD)/firmware-ota.bin
+
+	$(Q)cat $(YAOTA8266)/yaota8266.bin $(BUILD)/firmware-ota.bin > $@
+	$(Q)$(PYTHON) $(YAOTA8266)/ota-client/ota_client.py sign $@
+else
 $(FWBIN): $(BUILD)/firmware.elf
 	$(ECHO) "Create $@"
 	$(Q)esptool.py elf2image $^
 	$(Q)$(PYTHON) makeimg.py $(BUILD)/firmware.elf-0x00000.bin $(BUILD)/firmware.elf-0x[0-5][1-f]000.bin $@
+endif
 
 $(BUILD)/firmware.elf: $(OBJ)
 	$(ECHO) "LINK $@"
 	$(Q)$(LD) $(LDFLAGS) -o $@ $^ $(LIBS)
 	$(Q)$(SIZE) $@
 
-ota:
-	rm -f $(BUILD)/firmware.elf $(BUILD)/firmware.elf*.bin
-	$(MAKE) LD_FILES=boards/esp8266_ota.ld FWBIN=$(BUILD)/firmware-ota.bin
-
 include $(TOP)/py/mkrules.mk
 
 clean-modules:

ports/esp8266/README.md

@@ -23,6 +23,9 @@ Supported features include:
 
 Documentation is available at http://docs.micropython.org/en/latest/esp8266/quickref.html.
 
+The default build requires a 2MiB flash chip, but see below for support for
+1MiB and 512kiB options.
+
 Build instructions
 ------------------
 
@@ -67,10 +70,10 @@ Then to compile the ESP8266 firmware:
 
 ```
 $ cd ports/esp8266
-$ docker run --rm -v $HOME:$HOME -u $UID -w $PWD larsks/esp-open-sdk make -j BOARD=GENERIC
+$ docker run --rm -v $HOME:$HOME -u $UID -w $PWD larsks/esp-open-sdk make -j BOARD=ESP8266_GENERIC
 ```
 
-This will produce binary images in the `build-GENERIC/` subdirectory.
+This will produce binary images in the `build-ESP8266_GENERIC/` subdirectory.
 Substitute the board for whichever board you're using.
 
 __Building with a local toolchain__
@@ -106,10 +109,10 @@ Then to compile the ESP8266 firmware:
 
 ```
 $ cd ports/esp8266
-$ make -j BOARD=GENERIC
+$ make -j BOARD=ESP8266_GENERIC
 ```
 
-This will produce binary images in the `build-GENERIC/` subdirectory.
+This will produce binary images in the `build-ESP8266_GENERIC/` subdirectory.
 Substitute the board for whichever board you're using.
 
 
@@ -149,25 +152,29 @@ $ make PORT=/dev/ttyUSB0 FLASH_MODE=qio FLASH_SIZE=32m deploy
 (note that flash size is in megabits)
 
 If you want to flash manually using `esptool.py` directly, the image produced is
-`build-GENERIC/firmware-combined.bin`, to be flashed at 0x00000.
+`build-ESP8266_GENERIC/firmware.bin`, to be flashed at 0x00000.
 
-The default board definition is the directory `boards/GENERIC`.
+The default board definition is the directory `boards/ESP8266_GENERIC`.
 For a custom configuration you can define your own board in the directory `boards/`.
 
-The `BOARD` variable can be set on the make command line, for example:
-```bash
-$ make BOARD=GENERIC_512K
-```
+__Reduced FlashROM variants__
 
-__512KB FlashROM version__
+The normal build described above requires modules with at least 2MiB of
+FlashROM onboard. There's a special configuration for 512kiB modules, which can
+be built with the `FLASH_512K` variant. This configuration is highly limited,
+lacks filesystem support, WebREPL, and has many other features disabled. It's
+mostly suitable for advanced users who are interested to fine-tune options to
+achieve a required setup. If you are an end user, please consider using a
+module with at least 2MiB of FlashROM.
 
-The normal build described above requires modules with at least 1MB of FlashROM
-onboard. There's a special configuration for 512KB modules, which can be
-built with `make BOARD=GENERIC_512K`. This configuration is highly limited, lacks
-filesystem support, WebREPL, and has many other features disabled. It's mostly
-suitable for advanced users who are interested to fine-tune options to achieve a
-required setup. If you are an end user, please consider using a module with at
-least 1MB of FlashROM.
+A variant is also provided for 1MiB modules which just lacks the included
+micropython-lib packages.
+
+The variant can be set on the make command line, for example:
+```bash
+$ make BOARD=ESP8266_GENERIC BOARD_VARIANT=FLASH_512K
+$ make BOARD=ESP8266_GENERIC BOARD_VARIANT=FLASH_1M
+```
 
 First start
 -----------

ports/esp8266/boards/ESP8266_GENERIC/_boot.py

@@ -0,0 +1,6 @@
+# Minimal _boot.py for the 512kiB variant. Does not set up a block device or
+# filesystem. Other variants use esp8266/modules/_boot.py.
+
+import gc
+
+gc.threshold((gc.mem_free() + gc.mem_alloc()) // 4)

ports/esp8266/boards/GENERIC/board.json → ports/esp8266/boards/ESP8266_GENERIC/board.json

@@ -9,11 +9,13 @@
     ],
     "images": [],
     "mcu": "esp8266",
-    "product": "ESP8266 with 2MiB+ flash",
+    "product": "ESP8266",
     "thumbnail": "",
     "url": "https://www.espressif.com/en/products/modules",
     "variants": {
-        "ota": "OTA compatible"
+        "OTA": "OTA compatible",
+        "FLASH_1M": "1MiB flash",
+        "FLASH_512K": "512kiB flash"
     },
     "vendor": "Espressif"
 }

ports/esp8266/boards/GENERIC/board.md → ports/esp8266/boards/ESP8266_GENERIC/board.md

@@ -1,6 +1,13 @@
-The following are daily builds of the ESP8266 firmware for boards with at
-least 2MiB of flash.  They have the latest features and bug fixes, WebREPL is
-not automatically started, and debugging is enabled by default.
+The following are daily builds of the ESP8266 firmware. This will work on
+boards with at least 2MiB of flash.  They have the latest features and bug
+fixes, WebREPL is not automatically started, and debugging is enabled by
+default.
+
+For boards with 1MiB or 512kiB of flash, two variants are provided with reduced
+functionality. The 1MiB variant removes asyncio and FAT-filesystem support as
+well as some modules from micropython-lib. The 512kiB variant further removes
+all filesystem support, as well as framebuffer support, some Python language
+features, and has less detailed error messages.
 
 Note: v1.12-334 and newer (including v1.13) require an ESP8266 module with
 2MiB of flash or more, and use littlefs as the filesystem by default.  When

ports/esp8266/boards/ESP8266_GENERIC/mpconfigboard.h

@@ -0,0 +1,52 @@
+#if defined(MICROPY_ESP8266_2M)
+
+#define MICROPY_HW_BOARD_NAME "ESP module"
+#define MICROPY_HW_MCU_NAME "ESP8266"
+
+#define MICROPY_PERSISTENT_CODE_LOAD    (1)
+#define MICROPY_EMIT_XTENSA             (1)
+#define MICROPY_EMIT_INLINE_XTENSA      (1)
+
+#define MICROPY_DEBUG_PRINTERS          (1)
+#define MICROPY_ERROR_REPORTING         (MICROPY_ERROR_REPORTING_NORMAL)
+
+#define MICROPY_READER_VFS              (MICROPY_VFS)
+#define MICROPY_VFS                     (1)
+
+#define MICROPY_PY_CRYPTOLIB            (1)
+
+#elif defined(MICROPY_ESP8266_1M)
+
+#define MICROPY_HW_BOARD_NAME "ESP module (1M)"
+#define MICROPY_HW_MCU_NAME "ESP8266"
+
+#define MICROPY_PERSISTENT_CODE_LOAD    (1)
+#define MICROPY_EMIT_XTENSA             (1)
+#define MICROPY_EMIT_INLINE_XTENSA      (1)
+
+#define MICROPY_DEBUG_PRINTERS          (1)
+#define MICROPY_ERROR_REPORTING         (MICROPY_ERROR_REPORTING_NORMAL)
+
+#define MICROPY_READER_VFS              (MICROPY_VFS)
+#define MICROPY_VFS                     (1)
+
+
+#define MICROPY_PY_CRYPTOLIB            (1)
+
+#elif defined(MICROPY_ESP8266_512K)
+
+#define MICROPY_HW_BOARD_NAME "ESP module (512K)"
+#define MICROPY_HW_MCU_NAME "ESP8266"
+
+#define MICROPY_ERROR_REPORTING         (MICROPY_ERROR_REPORTING_TERSE)
+
+#define MICROPY_PY_FSTRINGS             (0)
+#define MICROPY_PY_BUILTINS_SLICE_ATTRS (0)
+#define MICROPY_PY_ALL_SPECIAL_METHODS  (0)
+#define MICROPY_PY_REVERSE_SPECIAL_METHODS (0)
+#define MICROPY_PY_SYS_STDIO_BUFFER     (0)
+#define MICROPY_PY_ASYNCIO              (0)
+#define MICROPY_PY_RE_SUB               (0)
+#define MICROPY_PY_FRAMEBUF             (0)
+
+#endif

ports/esp8266/boards/ESP8266_GENERIC/mpconfigboard.mk

@@ -0,0 +1,50 @@
+ifeq ($(BOARD_VARIANT),)
+LD_FILES = boards/esp8266_2MiB.ld
+
+MICROPY_ESPNOW ?= 1
+MICROPY_PY_BTREE ?= 1
+MICROPY_VFS_FAT ?= 1
+MICROPY_VFS_LFS2 ?= 1
+
+# Add asyncio and extra micropython-lib packages (in addition to the port manifest).
+FROZEN_MANIFEST ?= $(BOARD_DIR)/manifest_2MiB.py
+
+# Configure mpconfigboard.h.
+CFLAGS += -DMICROPY_ESP8266_2M
+endif
+
+ifeq ($(BOARD_VARIANT),FLASH_1M)
+LD_FILES = boards/esp8266_1MiB.ld
+
+MICROPY_ESPNOW ?= 1
+MICROPY_PY_BTREE ?= 1
+MICROPY_VFS_LFS2 ?= 1
+
+# Note: Implicitly uses the port manifest.
+
+# Configure mpconfigboard.h.
+CFLAGS += -DMICROPY_ESP8266_1M
+endif
+
+ifeq ($(BOARD_VARIANT),OTA)
+LD_FILES = boards/esp8266_ota.ld
+
+MICROPY_ESPNOW ?= 1
+MICROPY_PY_BTREE ?= 1
+MICROPY_VFS_LFS2 ?= 1
+
+# Note: Implicitly uses the port manifest.
+
+# Configure mpconfigboard.h.
+CFLAGS += -DMICROPY_ESP8266_1M
+endif
+
+ifeq ($(BOARD_VARIANT),FLASH_512K)
+LD_FILES = boards/esp8266_512kiB.ld
+
+# Note: Use the minimal manifest.py.
+FROZEN_MANIFEST ?= $(BOARD_DIR)/manifest_512kiB.py
+
+# Configure mpconfigboard.h.
+CFLAGS += -DMICROPY_ESP8266_512K
+endif