c - 制作ESP8266项目时获取C函数的 undefined reference

我按照本教程的说明将Kaa应用程序安装到ESP8266中，并做了一些修改后就可以正常工作：https://kaaproject.github.io/kaa/docs/v0.10.0/Programming-guide/Using-Kaa-endpoint-SDKs/C/SDK-ESP8266/

我必须进行的修改之一是由于字节溢出（箭头指向我所做的更改）而在eagle.app.v6.ld中移动一行代码：

...

.irom0.text : ALIGN(4)
{
_irom0_text_start = ABSOLUTE(.);
*(.literal.* .text.*) --> moved from ".text : ALIGN(4){...}"

...

}

...

完成此操作后，我仍然有一些字节溢出，因此我修改了文档中的原始cmake命令以禁用占用空间的cmake扩展：

cmake \
-DCMAKE_TOOLCHAIN_FILE=../kaa/toolchains/esp8266.cmake \
-DKAA_PLATFORM=esp8266 \
-DCMAKE_BUILD_TYPE=MinSizeRel \
-DWITH_EXTENSION_CONFIGURATION=OFF \
-DWITH_EXTENSION_EVENT=OFF \
-DWITH_EXTENSION_LOGGING=OFF \
-DWITH_EXTENSION_NOTIFICATION=OFF \
-DWITH_EXTENSION_USER=OFF \
-DWITH_ENCRYPTION=OFF \
-DKAA_MAX_LOG_LEVEL=3 ..

最后，当我运行make命令时。有效。然后，我创建了二进制文件并将其刷新到我的ESP中。然后，我将GPIO0重置为高电平（以便它可以从闪存启动），然后ESP发送“ Hello，Kaa！”。进入我连接的串行端口。

现在，但是。我正在尝试使ESP8266连接到我的Kaa服务器并生成一个端点配置文件，因此我需要代码来创建传输通道以与Bootstrap服务器和Operations Server进行通信。

为此，我尝试使用Your First Kaa应用程序中的代码，该代码会生成假的临时读数并接收配置架构，并通过日志附加程序将数据推送到我的Cassandra服务器：
https://kaaproject.github.io/kaa/docs/v0.10.0/Programming-guide/Your-first-Kaa-application/

因此，在尝试执行此操作时，我将目录保留为相同：

CMakeLists.txt
driver/
    uart.h
    uart.c
ld/
    eagle.app.v6.ld
    eagle.rom.addr.v6.ld
kaa/
    <put Kaa SDK here> --> replaced with new SDK with log and configuration schema
user/
    user_main.c
src/
    kaa_demo.c --> replaced with new code from "Your First Kaa Application"

然后，我将此代码替换为我的kaa_demo.c文件：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <time.h>
#include <kaa/kaa.h>
#include <kaa/platform/kaa_client.h>
#include <kaa/kaa_error.h>
#include <extensions/configuration/kaa_configuration_manager.h>
#include <extensions/logging/kaa_logging.h>
#include <kaa/gen/kaa_logging_gen.h>
#include <kaa/platform/kaa_client.h>
#include <kaa/utilities/kaa_log.h>
#include <kaa/platform-impl/common/ext_log_upload_strategies.h>

static int32_t sample_period;
static time_t  last_sample_time;
extern kaa_error_t ext_unlimited_log_storage_create(void **log_storage_context_p, kaa_logger_t *logger);
/* Retrieves current temperature. */
static int32_t get_temperature_sample(void)
{
    /* For the sake of example, random data is used */
    return rand() % 10 + 25;
}
/* Periodically called by Kaa SDK. */
static void example_callback(void *context)
{
    time_t current_time = time(NULL);
    /* Respect sample period */
    if (difftime(current_time, last_sample_time) >= sample_period) {
        int32_t temperature = get_temperature_sample();
        printf("Sampled temperature: %i\n", temperature);
        last_sample_time = current_time;
        kaa_user_log_record_t *log_record = kaa_logging_data_collection_create();
        log_record->temperature = temperature;
        kaa_logging_add_record(kaa_client_get_context(context)->log_collector, log_record, NULL);
    }
}
/* Receives new configuration data. */
static kaa_error_t on_configuration_updated(void *context, const kaa_root_configuration_t *conf)
{
    (void) context;
    printf("Received configuration data. New sample period: %i seconds\n", conf->sample_period);
    sample_period = conf->sample_period;
    return KAA_ERR_NONE;
}
int main(void)
{
    /* Init random generator used to generate temperature */
    srand(time(NULL));
    /* Prepare Kaa client. */
    kaa_client_t *kaa_client = NULL;
    kaa_error_t error = kaa_client_create(&kaa_client, NULL);
    if (error) {
        return EXIT_FAILURE;
    }
    /* Configure notification manager. */
    kaa_configuration_root_receiver_t receiver = {
        .context = NULL,
        .on_configuration_updated = on_configuration_updated
    };
    error = kaa_configuration_manager_set_root_receiver(
        kaa_client_get_context(kaa_client)->configuration_manager,
        &receiver);
    if (error) {
        return EXIT_FAILURE;
    }
    /* Obtain default configuration shipped within SDK. */
    const kaa_root_configuration_t *dflt = kaa_configuration_manager_get_configuration(
        kaa_client_get_context(kaa_client)->configuration_manager);
    printf("Default sample period: %i seconds\n", dflt->sample_period);
    sample_period = dflt->sample_period;

    /* Configure data collection. */
    void *log_storage_context         = NULL;
    void *log_upload_strategy_context = NULL;
    /* The internal memory log storage distributed with Kaa SDK. */
    error = ext_unlimited_log_storage_create(&log_storage_context,
        kaa_client_get_context(kaa_client)->logger);
    if (error) {
        return EXIT_FAILURE;
    }
    /* Create a strategy based on timeout. */
    error = ext_log_upload_strategy_create(
        kaa_client_get_context(kaa_client), &log_upload_strategy_context,
        KAA_LOG_UPLOAD_BY_TIMEOUT_STRATEGY);
    if (error) {
        return EXIT_FAILURE;
    }
    /* Strategy will upload logs every 5 seconds. */
    error = ext_log_upload_strategy_set_upload_timeout(log_upload_strategy_context, 5);
    if (error) {
        return EXIT_FAILURE;
    }
    /* Specify log bucket size constraints. */
    kaa_log_bucket_constraints_t bucket_sizes = {
         .max_bucket_size       = 32,   /* Bucket size in bytes. */
         .max_bucket_log_count  = 2,    /* Maximum log count in one bucket. */
    };
    /* Initialize the log storage and strategy (by default, they are not set). */
    error = kaa_logging_init(kaa_client_get_context(kaa_client)->log_collector,
        log_storage_context, log_upload_strategy_context, &bucket_sizes);
    if (error) {
        return EXIT_FAILURE;
    }

    /* Start Kaa SDK's main loop. example_callback is called once per second. */
    error = kaa_client_start(kaa_client, example_callback, kaa_client, 1);
    /* Should get here only after Kaa stops. */
    kaa_client_destroy(kaa_client);

    if (error) {
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

我将CMakeLists.txt文件保留为相同：

cmake_minimum_required(VERSION 3.0.2)

project(kaa_demo C)

# Add Kaa SDK directory
add_subdirectory(kaa)

# Add source files
add_library(kaa_demo_s STATIC user/user_main.c driver/uart.c src/kaa_demo.c)

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99")

if(NOT DEFINED ESP_RTOS_SDK)
    set(ESP_RTOS_SDK /opt/Espressif/esp-rtos-sdk)
endif()

# specify include directories
target_include_directories(kaa_demo_s PUBLIC driver)
target_include_directories(kaa_demo_s PUBLIC .)
target_include_directories(kaa_demo_s PUBLIC
                           ${ESP_RTOS_SDK}/extra_include
                           ${ESP_RTOS_SDK}/include
                           ${ESP_RTOS_SDK}/include/lwip
                           ${ESP_RTOS_SDK}/include/lwip/ipv4
                           ${ESP_RTOS_SDK}/include/lwip/ipv6
                           ${ESP_RTOS_SDK}/include/espressif/
                           )

exec_program(xtensa-lx106-elf-gcc .
            ARGS -print-libgcc-file-name
            OUTPUT_VARIABLE ESP8266_LIBGCC
            )

link_directories(${CMAKE_CURRENT_SOURCE_DIR}/ld)

target_link_libraries(kaa_demo_s PUBLIC
                      kaac
                      ${ESP_RTOS_SDK}/lib/libfreertos.a
                      ${ESP_RTOS_SDK}/lib/libhal.a
                      ${ESP_RTOS_SDK}/lib/libpp.a
                      ${ESP_RTOS_SDK}/lib/libphy.a
                      ${ESP_RTOS_SDK}/lib/libnet80211.a
                      ${ESP_RTOS_SDK}/lib/libwpa.a
                      ${ESP_RTOS_SDK}/lib/liblwip.a
                      ${ESP_RTOS_SDK}/lib/libmain.a
                      ${ESP_RTOS_SDK}/lib/libssl.a
                      ${ESP_RTOS_SDK}/lib/libhal.a
                      ${ESP8266_LIBGCC}
                      -Teagle.app.v6.ld
                      )

file(WRITE ${CMAKE_BINARY_DIR}/blank.c "")
add_executable(kaa_demo ${CMAKE_BINARY_DIR}/blank.c)

target_link_libraries(kaa_demo kaa_demo_s)

我保留了user_main.c文件相同：

#include <freertos/FreeRTOS.h>
#include <freertos/task.h>

#include "uart.h"

extern int main(void);

static void main_task(void *pvParameters)
{
    (void)pvParameters;
    main();
    for (;;);
}

void user_init(void)
{
    uart_init_new();
    UART_SetBaudrate(UART0, 115200);
    UART_SetPrintPort(UART0);

    portBASE_TYPE error = xTaskCreate(main_task, "main_task", 512, NULL, 2, NULL );
    if (error < 0) {
        printf("Error creating main_task! Error code: %ld\r\n", error);
    }
}

我离开了eagle.app.v6.ld（除了开头描述的修改之外）和eagle.rom.addr.ld，uart.h和uart.c相同（从github获得）

因此，当我转到构建目录并运行以下cmake命令时：

cmake \
-DCMAKE_TOOLCHAIN_FILE=../kaa/toolchains/esp8266.cmake \
-DKAA_PLATFORM=esp8266 \
-DCMAKE_BUILD_TYPE=MinSizeRel \
-DWITH_EXTENSION_CONFIGURATION=OFF \
-DWITH_EXTENSION_EVENT=OFF \
-DWITH_EXTENSION_LOGGING=OFF \
-DWITH_EXTENSION_NOTIFICATION=OFF \
-DWITH_EXTENSION_USER=OFF \
-DWITH_ENCRYPTION=OFF \
-DKAA_MAX_LOG_LEVEL=3 ..

我得到这个：（esp8266是我的用户名，kaa-app是包含以下内容的主目录：CMakeLists.txt，内部版本，驱动程序等）

-- Default SDK location will be used: /opt/Espressif/esp-rtos-sdk
-- Toolchain path: /opt/Espressif/crosstool-NG/builds/xtensa-lx106-elf
-- ESP8266 SDK path: /opt/Espressif/esp-rtos-sdk
==================================
BUILD_TYPE = MinSizeRel
KAA_PLATFORM = esp8266
KAA_MAX_LOG_LEVEL = 3
==================================
BOOTSTRAP ENABLED
PROFILE ENABLED
KAA WILL BE INSTALLED TO /usr/local
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE)
-- Configuring done
-- Generating done
-- Build files have been written to: /home/esp8266/Documents/kaa-app/build

因此，我运行了make，然后收到此错误：

libkaa_demo_s.a(kaa_demo2.c.obj):(.text.example_callback+0x8): undefined reference to `time'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.example_callback+0xc): undefined reference to `difftime'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.example_callback+0x20): undefined reference to `kaa_logging_add_record'
libkaa_demo_s.a(kaa_demo2.c.obj): In function `example_callback':
kaa_demo2.c:(.text.example_callback+0x35): undefined reference to `time'
kaa_demo2.c:(.text.example_callback+0x42): undefined reference to `difftime'
kaa_demo2.c:(.text.example_callback+0x9e): undefined reference to `kaa_logging_add_record'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x10): undefined reference to `srand'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x14): undefined reference to `kaa_configuration_manager_set_root_receiver'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x18): undefined reference to `kaa_configuration_manager_get_configuration'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x1c): undefined reference to `ext_unlimited_log_storage_create'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x20): undefined reference to `ext_log_upload_strategy_create'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x24): undefined reference to `ext_log_upload_strategy_set_upload_timeout'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x28): undefined reference to `kaa_logging_init'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x3a): undefined reference to `time'
libkaa_demo_s.a(kaa_demo2.c.obj):(.text.startup.main+0x40): undefined reference to `srand'
libkaa_demo_s.a(kaa_demo2.c.obj): In function `main':
kaa_demo2.c:(.text.startup.main+0x69): undefined reference to `kaa_configuration_manager_set_root_receiver'
kaa_demo2.c:(.text.startup.main+0x7b): undefined reference to `kaa_configuration_manager_get_configuration'
kaa_demo2.c:(.text.startup.main+0xa5): undefined reference to `ext_unlimited_log_storage_create'
kaa_demo2.c:(.text.startup.main+0xb8): undefined reference to `ext_log_upload_strategy_create'
kaa_demo2.c:(.text.startup.main+0xc5): undefined reference to `ext_log_upload_strategy_set_upload_timeout'
kaa_demo2.c:(.text.startup.main+0xe6): undefined reference to `kaa_logging_init'
collect2: error: ld returned 1 exit status
CMakeFiles/kaa_demo.dir/build.make:120: recipe for target 'kaa_demo' failed
make[2]: *** [kaa_demo] Error 1
CMakeFiles/Makefile2:107: recipe for target 'CMakeFiles/kaa_demo.dir/all' failed
make[1]: *** [CMakeFiles/kaa_demo.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

因此，似乎在尝试链接文件时找不到我包含的新标头：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <time.h>
#include <kaa/kaa.h>
#include <kaa/platform/kaa_client.h>
#include <kaa/kaa_error.h>
#include <extensions/configuration/kaa_configuration_manager.h>
#include <extensions/logging/kaa_logging.h>
#include <kaa/gen/kaa_logging_gen.h>
#include <kaa/platform/kaa_client.h>
#include <kaa/utilities/kaa_log.h>
#include <kaa/platform-impl/common/ext_log_upload_strategies.h>

但是，CMakeLists.txt中包含的目标目录包含我需要的头文件（用于C头）：

${ESP_RTOS_SDK}/extra_include

所以我真的不知道我需要添加或修改什么，我完全被卡住了。任何帮助将非常感激！谢谢！

最佳答案

对于data_collection，您必须设置-DWITH_EXTENSION_LOGGING=ON。

对于esp8266，您有一个不同的“ time.h”库/kaa/src/kaa/platform-impl/esp8266/platform，它不支持功能time(NULL)，但支持

kaa_time_t kaa_esp8266_get_time(void);

关于c - 制作ESP8266项目时获取C函数的 undefined reference ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/45802280/