[PATCH] net: lwip: add TFTPSERVERIP Kconfig option

[Jonas Karlman]

With the legacy networking stack, it is possible to use USE_SERVERIP,
SERVERIP and BOOTP_PREFER_SERVERIP Kconfg options to force use of a
specific TFTP server ip.

Using the lwIP networking stack use of the 'tftpserverip' environment
variable provide the closest equivalent functionality.

Add USE_TFTPSERVERIP and TFTPSERVERIP Kconfig options that can be used
to add the 'tftpserverip' environment variable to force use of a
specific TFTP server ip.

Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
---
 include/env_default.h |  3 +++
 net/lwip/Kconfig      | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/include/env_default.h b/include/env_default.h
index 7f8dc1c35a74..014873e304d8 100644
--- a/include/env_default.h
+++ b/include/env_default.h
@@ -58,6 +58,9 @@ const char default_environment[] = {
 #ifdef	CONFIG_USE_SERVERIP
 	"serverip="	CONFIG_SERVERIP			"\0"
 #endif
+#ifdef	CONFIG_USE_TFTPSERVERIP
+	"tftpserverip="	CONFIG_TFTPSERVERIP		"\0"
+#endif
 #ifdef	CONFIG_SYS_DISABLE_AUTOLOAD
 	"autoload=0\0"
 #endif
diff --git a/net/lwip/Kconfig b/net/lwip/Kconfig
index 5789766fe624..0cfd3eb2684f 100644
--- a/net/lwip/Kconfig
+++ b/net/lwip/Kconfig
@@ -72,4 +72,16 @@ config LWIP_TCP_WND
 	  but QEMU with "-net user" needs no more than a few KB or the
 	  transfer will stall and eventually time out.
 
+config USE_TFTPSERVERIP
+	bool "Set a default 'tftpserverip' value in the environment"
+	depends on CMD_TFTPBOOT
+	help
+	  Defines a default value for the IP address of a TFTP server to
+	  contact when using the "tftpboot" command.  (Environment variable
+	  "tftpserverip")
+
+config TFTPSERVERIP
+	string "Value of the default 'tftpserverip' value in the environment"
+	depends on USE_TFTPSERVERIP
+
 endif # NET_LWIP
-- 
2.52.0