sandbox: Filter arguments when starting U-Boot

The current method of starting U-Boot from U-Boot adds arguments to pass
the memory file through, so that memory is preserved. This is fine for a
single call, but if we call from TPL -> SPL -> U-Boot the arguments build
up and we have several memory files in the argument list.

Adjust the implementation to filter out arguments that we want to replace
with new ones. Also print a useful error if the exec() call fails.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index d817dcc..7b59e04 100644 (file)
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -576,10 +576,10 @@ static int make_exec(char *fname, const void *data, int size)
  */
 static int add_args(char ***argvp, char *add_args[], int count)
 {
-       char **argv;
+       char **argv, **ap;
        int argc;
 
-       for (argv = *argvp, argc = 0; (*argvp)[argc]; argc++)
+       for (argc = 0; (*argvp)[argc]; argc++)
                ;
 
        argv = os_malloc((argc + count + 1) * sizeof(char *));
@@ -587,7 +587,24 @@ static int add_args(char ***argvp, char *add_args[], int count)
                printf("Out of memory for %d argv\n", count);
                return -ENOMEM;
        }
-       memcpy(argv, *argvp, argc * sizeof(char *));
+       for (ap = *argvp, argc = 0; *ap; ap++) {
+               char *arg = *ap;
+
+               /* Drop args that we don't want to propagate */
+               if (*arg == '-' && strlen(arg) == 2) {
+                       switch (arg[1]) {
+                       case 'j':
+                       case 'm':
+                               ap++;
+                               continue;
+                       }
+               } else if (!strcmp(arg, "--rm_memory")) {
+                       ap++;
+                       continue;
+               }
+               argv[argc++] = arg;
+       }
+
        memcpy(argv + argc, add_args, count * sizeof(char *));
        argv[argc + count] = NULL;
 
@@ -611,6 +628,7 @@ static int os_jump_to_file(const char *fname)
        int fd, err;
        char *extra_args[5];
        char **argv = state->argv;
+       int argc;
 #ifdef DEBUG
        int i;
 #endif
@@ -630,11 +648,13 @@ static int os_jump_to_file(const char *fname)
        extra_args[1] = (char *)fname;
        extra_args[2] = "-m";
        extra_args[3] = mem_fname;
-       extra_args[4] = "--rm_memory";
-       err = add_args(&argv, extra_args,
-                      sizeof(extra_args) / sizeof(extra_args[0]));
+       argc = 4;
+       if (state->ram_buf_rm)
+               extra_args[argc++] = "--rm_memory";
+       err = add_args(&argv, extra_args, argc);
        if (err)
                return err;
+       argv[0] = (char *)fname;
 
 #ifdef DEBUG
        for (i = 0; argv[i]; i++)