cpu/esp32: build the SDK bootloader from source

.murdock

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 # uncomment and change this to limit builds, e.g.,
-#export BOARDS="samr21-xpro native"
+export BOARDS="esp32-ethernet-kit-v1_0 esp32-mh-et-live-minikit esp32-wemos-lolin-d32-pro esp32-ethernet-kit-v1_1 esp32-olimex-evb esp32-wroom-32 esp32-ethernet-kit-v1_2 esp32-ttgo-t-beam esp32-wrover-kit esp32-heltec-lora32-v2"
 # and / or
 #export APPS="examples/hello-world tests/unittests"
 

cpu/esp32/Kconfig

@@ -128,6 +128,12 @@ menu "ESP32 specific configurations"
         bool "Enable JTAG debugging interface"
         depends on HAS_ESP_JTAG
 
+config MODULE_ESP_BOOTLOADER
+    bool
+    default y
+    help
+        Compile Bootloader from ESP-IDF
+
 endmenu
 
 rsource "periph/Kconfig"

cpu/esp32/Makefile

@@ -8,6 +8,10 @@ DIRS += $(RIOTCPU)/esp_common
 DIRS += periph
 DIRS += vendor
 
+ifneq (, $(filter esp_bootloader, $(USEMODULE)))
+    DIRS += bootloader
+endif
+
 ifneq (, $(filter esp_eth, $(USEMODULE)))
     DIRS += esp-eth
 endif

cpu/esp32/Makefile.dep

@@ -5,6 +5,7 @@ include $(RIOTCPU)/esp_common/Makefile.dep
 USEPKG += esp32_sdk
 USEPKG += esp32_sdk_libs
 
+USEMODULE += esp_bootloader
 USEMODULE += esp_idf_driver
 USEMODULE += esp_idf_esp32
 USEMODULE += esp_idf_soc

cpu/esp32/Makefile.include

@@ -12,6 +12,7 @@ include $(RIOTCPU)/esp_common/Makefile.include
 TARGET_ARCH_ESP32 ?= xtensa-esp32-elf
 TARGET_ARCH ?= $(TARGET_ARCH_ESP32)
 
+PSEUDOMODULES += esp_bootloader
 PSEUDOMODULES += esp_gdbstub
 PSEUDOMODULES += esp_hw_counter
 PSEUDOMODULES += esp_i2c_hw
@@ -58,11 +59,16 @@ ifneq (,$(filter cpp,$(USEMODULE)))
   ARCHIVES += -lstdc++
 endif
 
+ifneq (,$(filter esp_bootloader,$(USEMODULE)))
+  # Bootloader file used by esptool.inc.mk
+  BOOTLOADER_BIN ?= $(BINDIR)/esp_bootloader/bootloader.bin
+endif
+
 ifneq (,$(filter esp_jtag,$(USEMODULE)))
   PROGRAMMERS_SUPPORTED += openocd
   PARTITION_POS = 0x8000
   OPENOCD_PRE_FLASH_CMDS = -c 'echo "Installing Bootloader at $(BOOTLOADER_POS)"' \
-    -c 'flash write_image erase "$(RIOTCPU)/$(CPU)/bin/bootloader.bin" $(BOOTLOADER_POS) bin' \
+    -c 'flash write_image erase "$(BOOTLOADER_BIN)" $(BOOTLOADER_POS) bin' \
     -c 'echo "Installing partition table at $(PARTITION_POS)"' \
     -c 'flash write_image erase "$(BINDIR)/partitions.bin" $(PARTITION_POS) bin'
   IMAGE_OFFSET = 0x10000
@@ -71,3 +77,5 @@ ifneq (,$(filter esp_jtag,$(USEMODULE)))
   # Without resets debug target fails with 'Target not examined yet'
   OPENOCD_DBG_EXTRA_CMD += -c 'reset halt'
 endif
+
+$(BOOTLOADER_BIN):

cpu/esp32/bootloader/Makefile

@@ -0,0 +1,140 @@
+# Bootloader binary blob
+MODULE := esp_bootloader
+
+# We are compiling the bootloader from the ESP32 SDK sources, so we
+# can't use the automatic module SRC discovery rules. Also, the compiled code
+# would not be linked into the application, instead it is linked into its own
+# binary file.
+NO_AUTO_SRC = 1
+
+include $(RIOTBASE)/Makefile.base
+
+# List of bootloader sources.
+include $(CURDIR)/bootloader.inc.mk
+
+# Bootloader baudrate, set to the application defined one if any or the default
+# in serial.inc.mk
+BOOTLOADER_BAUD ?= $(BAUD)
+
+# Bootloader sdkconfig.h defined in CURDIR directory.
+INCLUDES = \
+  -I$(dir $(RIOTBUILD_CONFIG_HEADER_C)) \
+  -I$(CURDIR) \
+  -I$(ESP32_SDK_DIR)/components \
+  -I$(ESP32_SDK_DIR)/components/esp32/include \
+  -I$(ESP32_SDK_DIR)/components/soc/esp32/include \
+  -I$(ESP32_SDK_DIR)/components/soc/include \
+  -I$(ESP32_SDK_DIR)/components/bootloader_support/include \
+  -I$(ESP32_SDK_DIR)/components/bootloader_support/include_priv \
+  -I$(ESP32_SDK_DIR)/components/log/include \
+  -I$(ESP32_SDK_DIR)/components/spi_flash/include \
+  #
+
+# BOOTLOADER_BUILD=1 signals to the SDK that's a bootloader build.
+CFLAGS = \
+  -DBOOTLOADER_BUILD=1 \
+  -DESP_PLATFORM \
+  -DRIOT_BOOTLOADER_BAUD=$(BOOTLOADER_BAUD) \
+  -DRIOT_FLASH_SIZE=$(FLASH_SIZE) \
+  -DWITH_POSIX \
+  -DHAVE_CONFIG_H \
+  -std=gnu99 \
+  -Og \
+  -ggdb \
+  -ffunction-sections \
+  -fdata-sections \
+  -fstrict-volatile-bitfields \
+  -mlongcalls \
+  -nostdlib \
+  -Wall \
+  -Werror=all \
+  -Wno-error=unused-function \
+  -Wno-error=unused-but-set-variable \
+  -Wno-error=unused-variable \
+  -Wno-error=deprecated-declarations \
+  -Wextra \
+  -Wno-unused-parameter \
+  -Wno-sign-compare \
+  -Wno-old-style-declaration \
+  #
+
+# Bootloader link flags. We use the SDK source and linking files instead of the
+# RIOT-OS ones to link the bootloader. Note that we also use the unmodified
+# SDK libraries.
+LINKFLAGS = \
+  -nostdlib \
+  -u call_user_start_cpu0 \
+  -Wl,--gc-sections \
+  -Wl,-static \
+  -Wl,--start-group \
+  $(ESP_SDK_BOOTLOADER_OBJS) \
+  -lgcc \
+  -lstdc++ \
+  -lgcov \
+  -T$(ESP32_SDK_DIR)/components/bootloader/subproject/main/esp32.bootloader.ld \
+  -T$(ESP32_SDK_DIR)/components/bootloader/subproject/main/esp32.bootloader.rom.ld \
+  -T$(ESP32_SDK_DIR)/components/esp32/ld/esp32.rom.ld \
+  -T$(ESP32_SDK_DIR)/components/esp32/ld/esp32.rom.spiram_incompatible_fns.ld \
+  -T$(ESP32_SDK_DIR)/components/esp32/ld/esp32.peripherals.ld \
+  -Wl,--end-group \
+  -Wl,-EL \
+  #
+
+# Build the bootloader on the application directory as it depends on the current
+# app settings from riotbuild.h.
+ESP_SDK_BOOTLOADER_DIR = $(BINDIR)/$(MODULE)
+ESP_SDK_BOOTLOADER_BIN = $(ESP_SDK_BOOTLOADER_DIR)/bootloader.bin
+ESP_SDK_BOOTLOADER_ELF = $(ESP_SDK_BOOTLOADER_DIR)/bootloader.elf
+
+# Objects that need to be filtered out because they are not part of the SDK
+# but are used as submodules and required by the Secure Boot which is not yet
+# supported due to a conflict of the packages `tinycrypt` and `micro-ecc`
+ESP_SDK_BOOTLOADER_OBJ_FILTER = \
+  components/bootloader_support/src/secure_boot.o \
+  components/bootloader_support/src/secure_boot_signatures.o \
+  components/micro-ecc/micro-ecc/uECC.o
+
+ESP_SDK_BOOTLOADER_OBJS = \
+  $(addprefix $(ESP_SDK_BOOTLOADER_DIR)/, \
+              $(filter-out $(ESP_SDK_BOOTLOADER_OBJ_FILTER), \
+                           $(ESP_SDK_BOOTLOADER_SRCS:%.c=%.o)))
+
+DEPS := $(ESP_SDK_BOOTLOADER_OBJS:%.o=%.d)
+-include $(DEPS)
+
+# ESP32 SDK submodules required for compilation of bootloader
+ESP32_SDK_SUBMODULES = $(ESP32_SDK_DIR)/components/micro-ecc/micro-ecc
+ESP32_SDK_SUBMODULES_GIT = $(addprefix $(ESP32_SDK_SUBMODULES),/.git)
+
+# Main module dependency. We only build the bootloader.bin from this module.
+$(MODULE).module: $(ESP_SDK_BOOTLOADER_BIN)
+
+OBJ_DEPS += $(CURDIR)/sdkconfig.h
+
+$(ESP_SDK_BOOTLOADER_DIR)/%.o: $(ESP32_SDK_DIR)/%.c $(OBJ_DEPS)
+	$(Q)mkdir -p $(dir $@)
+	$(Q)$(CCACHE) $(CC) \
+	  $(CFLAGS) $(INCLUDES) -MMD -MP -c $(abspath $<) -o $@
+
+$(ESP_SDK_BOOTLOADER_DIR):
+	mkdir -p $@
+
+$(ESP_SDK_BOOTLOADER_ELF): $(ESP_SDK_BOOTLOADER_OBJS) $(ESP_SDK_BOOTLOADER_SUPPORT_AR) \
+    | $(ESP_SDK_BOOTLOADER_DIR)
+	$(Q)$(CC) -o $@ $(LINKFLAGS) -Wl,-Map=$(@:%.elf=%.map)
+
+FLASH_CHIP = esp32
+ESPTOOL ?= $(RIOTTOOLS)/esptool/esptool.py
+# TODO: These should be exported/configurable from the app side. That would
+# require to export these values.
+FLASH_MODE ?= dout
+FLASH_FREQ ?= 40m
+FLASH_SIZE ?= 4
+
+# We use esptool to extract a version 1 app from the bootloader.elf. This is
+# like the regular objdump binary file but it contains a 16 byte header which
+# specifies the flash size, mode and speed that the ROM bootloader uses to load
+# this second-stage bootloader image.
+$(ESP_SDK_BOOTLOADER_BIN): $(ESP_SDK_BOOTLOADER_ELF)
+	$(Q)$(ESPTOOL) --chip $(FLASH_CHIP) elf2image --flash_mode $(FLASH_MODE) \
+	  --flash_size $(FLASH_SIZE)MB --flash_freq $(FLASH_FREQ) -o $@ $<

cpu/esp32/bootloader/bootloader.inc.mk

@@ -0,0 +1,32 @@
+# Generated by ./update_mk.sh, don't modify directly.
+
+ESP_SDK_BOOTLOADER_SRCS = \
+  components/bootloader/subproject/main/bootloader_start.c \
+  components/bootloader_support/src/bootloader_clock.c \
+  components/bootloader_support/src/bootloader_common.c \
+  components/bootloader_support/src/bootloader_flash.c \
+  components/bootloader_support/src/bootloader_init.c \
+  components/bootloader_support/src/bootloader_random.c \
+  components/bootloader_support/src/bootloader_sha.c \
+  components/bootloader_support/src/bootloader_utility.c \
+  components/bootloader_support/src/efuse.c \
+  components/bootloader_support/src/esp_image_format.c \
+  components/bootloader_support/src/flash_encrypt.c \
+  components/bootloader_support/src/flash_partitions.c \
+  components/bootloader_support/src/flash_qio_mode.c \
+  components/bootloader_support/src/secure_boot.c \
+  components/bootloader_support/src/secure_boot_signatures.c \
+  components/log/log.c \
+  components/micro-ecc/micro-ecc/uECC.c \
+  components/soc/esp32/cpu_util.c \
+  components/soc/esp32/gpio_periph.c \
+  components/soc/esp32/rtc_clk.c \
+  components/soc/esp32/rtc_init.c \
+  components/soc/esp32/rtc_periph.c \
+  components/soc/esp32/rtc_pm.c \
+  components/soc/esp32/rtc_sleep.c \
+  components/soc/esp32/rtc_time.c \
+  components/soc/esp32/soc_memory_layout.c \
+  components/soc/esp32/spi_periph.c \
+  components/spi_flash/spi_flash_rom_patch.c \
+  #

cpu/esp32/bootloader/sdkconfig.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2021 iosabi
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     pkg_esp32_sdk
+ * @{
+ *
+ * @file
+ * @brief       RIOT-OS modification of the bootloader SDK configuration
+ *
+ * The bootloader build of the ESP32 SDK needs some settings from the SDK
+ * configuration. These are normally generated by the menuconfig in the vendor
+ * SDK.
+ *
+ * Some of these parameters are configurable by the application. For example,
+ * the UART baudrate used by the console and the verbose level of the
+ * bootloader.
+ *
+ * @author      iosabi <iosabi@protonmail.com>
+ */
+
+#ifndef SDKCONFIG_H
+#define SDKCONFIG_H
+
+#ifndef DOXYGEN
+
+#include "riotbuild.h"
+
+#include "esp32_idf_version.h"
+#include "sdkconfig_default.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if MODULE_ESP_LOG_COLORED
+#define CONFIG_LOG_COLORS 1
+#endif
+
+#ifndef CONFIG_LOG_BOOTLOADER_LEVEL
+/*
+ * SDK Log levels:
+ *
+ *  0 = NONE
+ *  1 = ERROR
+ *  2 = WARN
+ *  3 = INFO
+ *  4 = DEBUG
+ *  5 = VERBOSE
+ */
+#if MODULE_ESP_LOG_STARTUP
+#define CONFIG_LOG_BOOTLOADER_LEVEL 3 /* INFO */
+#else
+#define CONFIG_LOG_BOOTLOADER_LEVEL 0 /* NONE */
+#endif
+#endif
+
+#if FLASH_MODE_QIO
+#define CONFIG_FLASHMODE_QIO 1
+#elif FLASH_MODE_QOUT
+#define CONFIG_FLASHMODE_QOUT 1
+#elif FLASH_MODE_DIO
+#define CONFIG_FLASHMODE_DIO 1
+#elif FLASH_MODE_DOUT
+#define CONFIG_FLASHMODE_DOUT 1
+#else
+#error "Unknown flash mode selected."
+#endif
+
+/*
+ * Bootloader output baudrate, defined by the app settings as BAUD or
+ * BOOTLOADER_BAUD.
+ */
+#define CONFIG_CONSOLE_UART_BAUDRATE (RIOT_BOOTLOADER_BAUD)
+
+/*
+ * The Makefile FLASH_SIZE value is set in MB, but set as bytes to
+ * CONFIG_SPI_FLASH_SIZE.
+ */
+#define CONFIG_SPI_FLASH_SIZE ((RIOT_FLASH_SIZE) * 1024 * 1024)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* DOXYGEN */
+/** @} */
+
+#endif /* SDKCONFIG_H */

cpu/esp32/bootloader/sdkconfig_default.h

@@ -0,0 +1,29 @@
+/*
+ * Generated by ./update_mk.sh, don't modify directly.
+ * Default CONFIG_ parameters from the SDK package.
+ */
+
+#ifndef SDKCONFIG_DEFAULT_H
+#define SDKCONFIG_DEFAULT_H
+
+#ifndef DOXYGEN
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define CONFIG_BOOTLOADER_VDDSDIO_BOOST_1_9V 1
+#define CONFIG_CONSOLE_UART_NUM 0
+#define CONFIG_ESP32_DEBUG_OCDAWARE 1
+#define CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ 160
+#define CONFIG_ESP32_XTAL_FREQ 40
+#define CONFIG_LOG_DEFAULT_LEVEL 3
+#define CONFIG_PARTITION_TABLE_OFFSET 0x8000
+#define CONFIG_SPI_FLASH_ROM_DRIVER_PATCH 1
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* DOXYGEN */
+#endif /* SDKCONFIG_DEFAULT_H */