Re: [U-Boot] [PATCH] Add support for setting environment variable from RAM.

Hi Eric,

On Tue, 2009-02-03 at 08:28 -0700, Eric Nelson (Boundary Devices) wrote:

/************************************************************************

• • Set a new environment variable from RAM.
• • Requires three arguments: the variable name, a memory address and a length.
• • Deletes the environment variable if the length is zero.
• */

+int do_ramenv(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{

• unsigned long len, i;
• char *addr;
• if (argc != 4) {

• cmd_usage(cmdtp);
  

• return 1;
  

• }
• addr = (char *)simple_strtol(argv[2], NULL, 16);
• len = simple_strtol(argv[3], NULL, 16);
• if (!addr || !len) {

• cmd_usage(cmdtp);
  

• return 1;
  

• }
• addr[len] = '\0';
• for (i = 0; i < len; i++) {

• /* turn newlines into semicolon */
  

• if (addr[i] == '\n')
  

• 	addr[i] = ';'; /* ignore dos-style newlines */
  

• if (addr[i] == '\r')
  

• 	addr[i] = ' '; /* accept sh-comments and discard them */
  

• if (addr[i] == '#') {
  

• 	while (addr[i] && addr[i] != '\n')
  

• 		addr[i++] = ' ';
  

• 	i--;
  

• }
  

• }
• setenv(argv[1], addr);
• return 0;

+}

+/************************************************************************

• Look up variable from environment,
• return address of storage for that variable,
• or NULL if not found

@@ -605,6 +643,14 @@ U_BOOT_CMD( " - delete environment variable 'name'\n" );

+U_BOOT_CMD(

• ramenv, 4, 0, do_ramenv,
• "ramenv - get environment variable from ram\n",

The "ramenv - " and "\n" are no longer used in the above line.

• "name addr maxlen\n"
• " - set environment variable 'name' from addr 'addr'\n"
• " - delete environment variable if maxlen is 0\n"

+);

#if defined(CONFIG_CMD_ASKENV)

U_BOOT_CMD(

In the email thread you mentioned above, Detlev mentions 2 alternatives to the "ramenv" command - loading a uImage script and running it via autoscr, or modifying autoscr to be able to raw files (non-uImages). Both of these methods seem cleaner and more flexible at a glance. Is there a specific reason using autoscr wouldn't work for your setup?

For example, what is the process to load multiple environment variables with the ramenv command? If I understand correctly, in order to load 10 environment variables you'd have to repeat the process of "load a file to RAM, run ramenv" 10 times? That seems much more difficult than loading 1 file with 10 environment variables and running autoscr once.

Best, Peter