🆕 在shell中启动另一个程序

user/apps/Makefile

@@ -1,5 +1,5 @@
 
-user_apps_sub_dirs=shell
+user_apps_sub_dirs=shell about
 
 all:
 	@list='$(user_apps_sub_dirs)'; for subdir in $$list; do \

user/apps/about/Makefile

@@ -1,6 +1,6 @@
 all: about.o
 
-	ld -b elf64-x86-64 -z muldefs -o $(tmp_output_dir)/about  $(shell find . -name "*.o") $(shell find $(sys_libs_dir) -name "*.o") -T shell.lds
+	ld -b elf64-x86-64 -z muldefs -o $(tmp_output_dir)/about  $(shell find . -name "*.o") $(shell find $(sys_libs_dir) -name "*.o") -T about.lds
 
 	objcopy -I elf64-x86-64 -S -R ".eh_frame" -R ".comment" -O elf64-x86-64 $(tmp_output_dir)/about $(output_dir)/about.elf
 about.o: about.c

user/apps/about/about.c

@@ -3,5 +3,6 @@
 int main()
 {
     printf("Hello World!\n");
+    exit(0);
     while(1);
 }

user/apps/about/about.lds

@@ -0,0 +1,50 @@
+
+OUTPUT_FORMAT("elf64-x86-64","elf64-x86-64","elf64-x86-64")
+OUTPUT_ARCH(i386:x86-64)
+ENTRY(main)
+
+SECTIONS
+{
+
+	. = 0x800000;
+	
+	
+	.text :
+	{
+		_text = .;
+		
+		*(.text)
+		
+		_etext = .;
+	}
+	. = ALIGN(8);
+	
+	.data :
+	{
+		_data = .;
+		*(.data)
+		
+		_edata = .;
+	}
+
+
+	rodata_start_pa = .;
+	.rodata :
+	{
+		_rodata = .;	
+		*(.rodata)
+		_erodata = .;
+	}
+
+	
+	.bss :
+	{
+		_bss = .;
+		*(.bss)
+		_ebss = .;
+	}
+
+	_end = .;
+
+
+}

user/apps/shell/cmd.c

@@ -369,16 +369,15 @@ int shell_cmd_exec(int argc, char **argv)
 {
     pid_t pid = fork();
     int retval = 0;
-    printf("  pid=%d  \n",pid);
+    // printf("  pid=%d  \n",pid);
 
-    while(1);
     if (pid == 0)
     {
-        printf("child proc\n");
+        // printf("child proc\n");
         // 子进程
         int path_len = 0;
         char *file_path = get_target_filepath(argv[1], &path_len);
-        printf("before execv, path=%s\n", file_path);
+        // printf("before execv, path=%s, argc=%d\n", file_path, argc);
         execv(file_path, argv);
         free(argv);
         while(1);
@@ -387,13 +386,13 @@ int shell_cmd_exec(int argc, char **argv)
     else
     {
         printf("parent process wait for pid:[ %d ]\n", pid);
-        while(1);
+ 
         waitpid(pid, &retval, 0);
         printf("parent process wait pid [ %d ], exit code=%d\n", pid, retval);
         free(argv);
     }
 
-    while(1);
+
 }
 
 /**

user/apps/shell/shell.c

@@ -42,23 +42,10 @@ void main_loop(int kb_fd)
 
     unsigned char input_buffer[INPUT_BUFFER_SIZE] = {0};
 
-    sbrk(24);
-    // brk(0x700000000000 + (1<<21));
-    pid_t pid = fork();
-    int retval = 0;
-    
-
-    for(int i=0;i<10;++i)
-        printf("  @pid=%d  ", pid);
-    
-    if(pid == 0)
-    {
-        int a = 1/0;
-    }
     // 初始化当前工作目录的路径
     shell_current_path = (char *)malloc(3);
 
-        memset(shell_current_path, 0, 3);
+    memset(shell_current_path, 0, 3);
     shell_current_path[0] = '/';
     shell_current_path[1] = '\0';