Getting undefined references for C functions while

Question

I followed this tutorial for installing a Kaa application into an ESP8266, and it worked after a few modifications: https://kaaproject.github.io/kaa/docs/v0.10.0/Programming-guide/Using-Kaa-endpoint-SDKs/C/SDK-ESP8266/

One of the modifications I had to make was to move a line of code in eagle.app.v6.ld because of byte overflow (arrow points to change I made):

...

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

...

}

...

After I did this I still had some byte overflow, so I modified the original cmake command from the documentation to disable cmake extensions that were taking up space:

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 ..

Finally, when I ran the make command. it worked. I then created and flashed the binaries into my ESP. Then I reset my ESP with GPIO0 high (so it can boot from flash) and the ESP sent "Hello, Kaa!" into the serial port I was connected to.

Now, however. I am trying to make it so that my ESP8266 connects to my Kaa server and generates an Endpoint Profile, so I need the code to create a transport channel to communicate to both the Bootstrap server and Operations server.

To do this, I tried using the code from Your First Kaa Application that generates fake temp readings and receives the configuration schema and pushes data to my Cassandra server via log appender: https://kaaproject.github.io/kaa/docs/v0.10.0/Programming-guide/Your-first-Kaa-application/

So in my attempt to do this, I left my directory the same:

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"

I then replaced this code into my kaa_demo.c file:

#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;
}

I left the CMakeLists.txt file the same:

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)

I left the user_main.c file the same:

#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);
    }
}

I left eagle.app.v6.ld (except for the modification described in the beginning) and eagle.rom.addr.ld, uart.h, and uart.c the same (obtained from github)

So when I change to the build directory and run this cmake command:

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 ..

I get this: (esp8266 is my username, kaa-app is the main directory that contains: CMakeLists.txt, build, drivers, etc.)

-- 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

So then I run make, and I get this error:

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

So it seems that when it tries linking the files it cannot find the new headers I included:

#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>

However, the target directory that is included in CMakeLists.txt contains the header files that I need (for the C headers):

${ESP_RTOS_SDK}/extra_include

So I really do not know what I need to add or modify, I am completely stuck. Any help would be much appreciated! Thanks!

Answer 1

For data_collection you have to set -DWITH_EXTENSION_LOGGING=ON .

For esp8266 you have a different "time.h" library /kaa/src/kaa/platform-impl/esp8266/platform that doesn't support the function time(NULL), but support

kaa_time_t kaa_esp8266_get_time(void);