[PATCH v9 7/7] bootm: Tidy up use of autostart env var

[Simon Glass]

This has different semantics in different places. Go with the bootm method
and put it in a common function so that the behaviour is consistent in
U-Boot. Update the docs.

To be clear, this changes the way that 'bootelf' and standalone boot
work. Before, if autostart was set to "fred" or "YES", for example, they
would consider that a "yes". This may change behaviour for some boards,
but the only in-tree boards which mention autostart use "no" to disable
it, which will still work.

Signed-off-by: Simon Glass <sjg at chromium.org>
Suggested-by: Wolfgang Denk <wd at denx.de>
---

Changes in v9:
- More bikeshedding on env_get_autostart()
- Fix '<vendor><board>' in cover letter
- Use env_get_yesno() in env_get_autostart() and update docs

Changes in v8:
- Go into more detail about the change of behaviour with autostart

Changes in v7:
- Update the cover letter

Changes in v6:
- Add new patch to tidy up use of autostart env var

 cmd/bootm.c               | 4 +---
 cmd/elf.c                 | 3 +--
 common/bootm_os.c         | 5 +----
 doc/usage/environment.rst | 5 +++--
 env/common.c              | 5 +++++
 include/env.h             | 7 +++++++
 6 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/cmd/bootm.c b/cmd/bootm.c
index 92468d09a1f..b82a872a86c 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -140,9 +140,7 @@ int do_bootm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 
 int bootm_maybe_autostart(struct cmd_tbl *cmdtp, const char *cmd)
 {
-	const char *ep = env_get("autostart");
-
-	if (ep && !strcmp(ep, "yes")) {
+	if (env_get_autostart()) {
 		char *local_args[2];
 		local_args[0] = (char *)cmd;
 		local_args[1] = NULL;
diff --git a/cmd/elf.c b/cmd/elf.c
index d75b21461c2..2b33c50bd02 100644
--- a/cmd/elf.c
+++ b/cmd/elf.c
@@ -41,7 +41,6 @@ int do_bootelf(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	unsigned long addr; /* Address of the ELF image */
 	unsigned long rc; /* Return value from user code */
 	char *sload = NULL;
-	const char *ep = env_get("autostart");
 	int rcode = 0;
 
 	/* Consume 'bootelf' */
@@ -69,7 +68,7 @@ int do_bootelf(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	else
 		addr = load_elf_image_shdr(addr);
 
-	if (ep && !strcmp(ep, "no"))
+	if (!env_get_autostart())
 		return rcode;
 
 	printf("## Starting application at 0x%08lx ...\n", addr);
diff --git a/common/bootm_os.c b/common/bootm_os.c
index 39623f9126b..f30dcebbf7d 100644
--- a/common/bootm_os.c
+++ b/common/bootm_os.c
@@ -26,12 +26,9 @@ DECLARE_GLOBAL_DATA_PTR;
 static int do_bootm_standalone(int flag, int argc, char *const argv[],
 			       bootm_headers_t *images)
 {
-	char *s;
 	int (*appl)(int, char *const[]);
 
-	/* Don't start if "autostart" is set to "no" */
-	s = env_get("autostart");
-	if ((s != NULL) && !strcmp(s, "no")) {
+	if (!env_get_autostart()) {
 		env_set_hex("filesize", images->os.image_len);
 		return 0;
 	}
diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst
index a3eddbaaf2e..282550a3f44 100644
--- a/doc/usage/environment.rst
+++ b/doc/usage/environment.rst
@@ -165,8 +165,9 @@ autostart
     be automatically started (by internally calling
     "bootm")
 
-    If set to "no", a standalone image passed to the
-    "bootm" command will be copied to the load address
+    If unset, or set to "1"/"yes"/"true" (case insensitive, just the first
+    character is enough), a standalone image
+    passed to the "bootm" command will be copied to the load address
     (and eventually uncompressed), but NOT be started.
     This can be used to load and uncompress arbitrary
     data.
diff --git a/env/common.c b/env/common.c
index 81e9e0b2aaf..e46a9ee644e 100644
--- a/env/common.c
+++ b/env/common.c
@@ -47,6 +47,11 @@ int env_get_yesno(const char *var)
 		1 : 0;
 }
 
+bool env_get_autostart(void)
+{
+	return env_get_yesno("autostart") == 1;
+}
+
 /*
  * Look up the variable from the default environment
  */
diff --git a/include/env.h b/include/env.h
index d5e2bcb530f..fdad495691f 100644
--- a/include/env.h
+++ b/include/env.h
@@ -143,6 +143,13 @@ int env_get_f(const char *name, char *buf, unsigned int len);
  */
 int env_get_yesno(const char *var);
 
+/**
+ * env_get_autostart() - Check if autostart is enabled
+ *
+ * @return true if the "autostart" env var exists and is set to "yes"
+ */
+bool env_get_autostart(void);
+
 /**
  * env_set() - set an environment variable
  *
-- 
2.33.0.1079.g6e70778dc9-goog