[U-Boot] [PATCH v4 01/10] Add getenv_ulong() to read an integer from an environment variable

[Simon Glass]

This is not an uncommon operation in U-Boot, so let's put it in a common
function.

Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v2:
- Fix commit title from getenv_int() to getenv_ulong()

Changes in v3:
- Move getenv_ulong() function comment into C file
- Add special code for early environment access

Changes in v4:
- Change getenv_ulong() implementation back to version 2
- Add a comment as to why this is ok

 common/cmd_nvedit.c |   20 ++++++++++++++++++++
 include/common.h    |    1 +
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
index 101bc49..fa99c44 100644
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -540,6 +540,26 @@ int getenv_f(const char *name, char *buf, unsigned len)
 	return -1;
 }
 
+/**
+ * Decode the integer value of an environment variable and return it.
+ *
+ * @param name		Name of environemnt variable
+ * @param base		Number base to use (normally 10, or 16 for hex)
+ * @param default_val	Default value to return if the variable is not
+ *			found
+ * @return the decoded value, or default_val if not found
+ */
+ulong getenv_ulong(const char *name, int base, ulong default_val)
+{
+	/*
+	 * We can use getenv() here, even before relocation, since the
+	 * environment variable value is an integer and thus short.
+	 */
+	const char *str = getenv(name);
+
+	return str ? simple_strtoul(str, NULL, base) : default_val;
+}
+
 #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
 
 int do_env_save(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
diff --git a/include/common.h b/include/common.h
index eb19a44..27f5e98 100644
--- a/include/common.h
+++ b/include/common.h
@@ -288,6 +288,7 @@ void	env_relocate (void);
 int	envmatch     (uchar *, int);
 char	*getenv	     (const char *);
 int	getenv_f     (const char *name, char *buf, unsigned len);
+ulong getenv_ulong(const char *name, int base, ulong default_val);
 int	saveenv	     (void);
 #ifdef CONFIG_PPC		/* ARM version to be fixed! */
 int inline setenv    (const char *, const char *);
-- 
1.7.3.1