内存管理文档4→2合并：报告/规划并入主文档，lftpd静态化降栈峰值，同步架构/FTP/部署文档

Drivers/BSP/NET/lftpd/lftpd.c

@@ -66,8 +66,8 @@ static int send_response(int socket, int code, bool include_code,
                          bool multiline_start, const char *format, ...)
 {
     va_list args;
-    char message[256];
-    char response[512];
+    static char message[256];   /* static: off-stack, single-client ftpTask */
+    static char response[512];  /* static: off-stack, single-client ftpTask */
 
     va_start(args, format);
     vsnprintf(message, sizeof(message), format, args);
@@ -108,7 +108,7 @@ static int send_list(int socket, const char *path)
         return -1;
     }
 
-    char name[256];
+    static char name[256];      /* static: off-stack, single-client ftpTask */
     uint32_t size;
     int is_dir;
 
@@ -133,7 +133,7 @@ static int send_nlst(int socket, const char *path)
         return -1;
     }
 
-    char name[256];
+    static char name[256];      /* static: off-stack, single-client ftpTask */
     uint32_t size;
     int is_dir;
 
@@ -155,7 +155,7 @@ static int send_file(int socket, const char *path)
         return -1;
     }
 
-    unsigned char buffer[1024];
+    static unsigned char buffer[1024];  /* static: 1KB off-stack, single-client ftpTask */
     int read_len;
 
     while ((read_len = lftpd_io_read(fh, buffer, sizeof(buffer))) > 0) {
@@ -184,7 +184,7 @@ static int receive_file(int socket, const char *path)
         return -1;
     }
 
-    unsigned char buffer[1024];
+    static unsigned char buffer[1024];  /* static: 1KB off-stack, single-client ftpTask */
     int err;
     int total = 0;
 
@@ -550,7 +550,7 @@ static int handle_control_channel(lftpd_client_t *client)
         goto cleanup;
     }
 
-    char read_buffer[512];
+    static char read_buffer[512];  /* static: off-stack, single-client ftpTask */
 
     while (err == 0) {
         int line_len = lftpd_inet_read_line(client->socket, read_buffer,
@@ -584,7 +584,7 @@ static int handle_control_channel(lftpd_client_t *client)
         bool matched = false;
         for (int i = 0; commands[i].command; i++) {
             if (strcmp(commands[i].command, command_tmp) == 0) {
-                char arg_buf[512];
+                static char arg_buf[512];  /* static: off-stack, single-client ftpTask */
                 const char *arg = NULL;
 
                 if (index < (int)strlen(read_buffer)) {
@@ -649,7 +649,7 @@ int lftpd_start(const char *directory, int port, lftpd_t *lftpd)
             }
         }
 
-        lftpd_client_t client;
+        static lftpd_client_t client;  /* static: off-stack session context (single session) */
         memset(&client, 0, sizeof(client));
         strncpy(client.directory, directory, sizeof(client.directory) - 1);
         client.directory[sizeof(client.directory) - 1] = '\0';