Support for building and running external apps (#112)

Libraries/elf_loader/examples/elf_loader_example/main/CMakeLists.txt

@@ -0,0 +1,3 @@
+idf_component_register(SRCS "elf_loader_example_main.c"
+                       INCLUDE_DIRS ""
+                       EMBED_TXTFILES "test.elf")

Libraries/elf_loader/examples/elf_loader_example/main/Kconfig.projbuild

@@ -0,0 +1,12 @@
+menu "ELF Loader Example Configuration"
+
+    config ELF_LOADER_MAIN_ARGS
+        bool "Support arguments for ELF main"
+        default n
+    
+    config ELF_LOADER_MAIN_ARGS_STRING
+        string "Arguments of ELF main"
+        default "main"
+        depends on ELF_LOADER_MAIN_ARGS
+
+endmenu

Libraries/elf_loader/examples/elf_loader_example/main/elf_loader_example_main.c

@@ -0,0 +1,119 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <sys/errno.h>
+
+#include "esp_log.h"
+#include "esp_elf.h"
+
+static const char *TAG = "elf_loader";
+
+extern const uint8_t test_elf_start[] asm("_binary_test_elf_start");
+extern const uint8_t test_elf_end[]   asm("_binary_test_elf_end");
+
+#ifdef CONFIG_ELF_LOADER_MAIN_ARGS
+static int elf_args_decode(const char *str, int *argc, char ***argv)
+{
+    int n;
+    char **argv_buf;
+    char *s;
+    char *pbuf;
+    int len;
+
+    s = (char *)str;
+    n = 1;
+    len = 1;
+    while (*s) {
+        if (*s++ == ' ') {
+            n++;
+        }
+
+        len++;
+    }
+
+    pbuf = malloc(n * sizeof(char *) + len);
+    if (!pbuf) {
+        return -ENOMEM;    
+    }
+
+    argv_buf = (char **)pbuf;
+    s = pbuf + n * sizeof(char *);
+    memcpy(s, str, len);
+    for (int i = 0; i < n; i++) {
+        argv_buf[i] = s;
+
+        while (*s != ' ' || *s == 0) {
+            s++;
+        }
+
+        *s++ = 0;
+    }
+
+    *argc = n;
+    *argv = argv_buf;
+
+    return 0;
+}
+#endif
+
+int app_main(void)
+{
+    int ret;
+    int argc;
+    char **argv;
+    esp_elf_t elf;
+    const uint8_t *buffer = test_elf_start;
+
+    ESP_LOGI(TAG, "Start to relocate ELF file");
+
+#ifdef CONFIG_ELF_LOADER_MAIN_ARGS
+    if (strlen(CONFIG_ELF_LOADER_MAIN_ARGS_STRING) <= 0) {
+        ESP_LOGE(TAG, "Failed to check arguments %s",
+                 CONFIG_ELF_LOADER_MAIN_ARGS_STRING);   
+        return -1;     
+    }
+
+    ret = elf_args_decode(CONFIG_ELF_LOADER_MAIN_ARGS_STRING, &argc, &argv);
+    if (ret < 0) {
+        ESP_LOGE(TAG, "Failed to decode arguments %s errno=%d",
+                 CONFIG_ELF_LOADER_MAIN_ARGS_STRING, ret);
+        return ret; 
+    }
+#else
+    argc = 0;
+    argv = NULL;
+#endif
+
+    ret = esp_elf_init(&elf);
+    if (ret < 0) {
+        ESP_LOGE(TAG, "Failed to initialize ELF file errno=%d", ret);
+        return ret;
+    }
+
+    ret = esp_elf_relocate(&elf, buffer);
+    if (ret < 0) {
+        ESP_LOGE(TAG, "Failed to relocate ELF file errno=%d", ret);
+        return ret;
+    }
+
+    ESP_LOGI(TAG, "Start to run ELF file");
+
+    esp_elf_request(&elf, 0, argc, argv);
+
+    ESP_LOGI(TAG, "Success to exit from ELF file");
+
+    esp_elf_deinit(&elf);
+
+#ifdef CONFIG_ELF_LOADER_MAIN_ARGS
+    if (argv) {
+        free(argv);
+    }
+#endif
+
+    return 0;
+}

Libraries/elf_loader/examples/elf_loader_example/main/idf_component.yml

@@ -0,0 +1,5 @@
+dependencies:
+  elf_loader:
+    version: "0.*"
+    override_path: "../../../../components/elf_loader"
+