Merge patch series "net: migrate NO_NET out of the networking stack choice"

Quentin Schulz <[email protected]> says:

This migrates the net options away from the main Kconfig to net/Kconfig,
rename the current NET option to NET_LEGACY to really highlight what it
is and hopefully encourage more people to use lwIP, add a new NET
menuconfig (but keep NO_NET as an alias to NET=n for now) which then
allows us to replace all the "if legacy_stack || lwip_stack" checks with
"if net_support" which is easier to read and maintain.

The only doubt I have is wrt SYS_RX_ETH_BUFFER which seems to be needed
for now even when no network is configured? Likely due to
include/net-common.h with PKTBUFSRX?

No change in behavior is intended. Only change in defconfig including
other defconfigs where NO_NET=y or NET is not set, in which case NO_NET
is not set or NET=y should be set in the top defconfig. Similar change
required for config fragments. See commit log in patch adding NET
menuconfig for details.

This was tested based on 70fd0c3bb7c2 ("x86: there is no
CONFIG_UBOOT_ROMSIZE_KB_12288"), from within the GitLab CI container
trini/u-boot-gitlab-ci-runner:noble-20251013-23Jan2026 and set up
similarly as in "build all platforms in a single job" GitLab CI job.

 #!/usr/bin/env bash
 set -o pipefail
 set -eux

 ARGS="-BvelPEWM --reproducible-builds --step 0"
 ./tools/buildman/buildman -o ${O} --force-build $ARGS -CE $*
 ./tools/buildman/buildman -o ${O} $ARGS -Ssd $*

O=../build/u-boot/ ../u-boot.sh -b master^..b4/net-kconfig |& tee ../log.txt

I can't really decipher the log.txt, but there's no line starting with
+ which would be an error according to tools/buildman/builder.py help
text. Additionally, because I started the script with set -e set and
because buildman has an exit code != 0 when it fails to build a board,
and I have the summary printed (which is the second buildman call), I
believe it means all builds passed.

The summary is the following:
   aarch64: (for 537/537 boards) all +0.0 rodata +0.0
            uniphier_v8    : all +1 rodata +1
               u-boot: add: 0/0, grow: 1/0 bytes: 1/0 (1)
                 function                                   old     new   delta
                 data_gz                                  10640   10641      +1
       arm: (for 733/733 boards) all -0.0 rodata -0.0
            uniphier_v7    : all -1 rodata -1
               u-boot: add: 0/0, grow: 0/-1 bytes: 0/-1 (-1)
                 function                                   old     new   delta
                 data_gz                                  11919   11918      -1
            opos6uldev     : all -3 rodata -3
               u-boot: add: 0/0, grow: 0/-1 bytes: 0/-3 (-3)
                 function                                   old     new   delta
                 data_gz                                  18778   18775      -3
            uniphier_ld4_sld8: all -3 rodata -3
               u-boot: add: 0/0, grow: 0/-1 bytes: 0/-3 (-3)
                 function                                   old     new   delta
                 data_gz                                  11276   11273      -3
            stemmy         : all -20 rodata -20
               u-boot: add: 0/0, grow: 0/-1 bytes: 0/-20 (-20)
                 function                                   old     new   delta
                 data_gz                                  15783   15763     -20

As far as I could tell this data_gz is an automatically generated array
when CONFIG_CMD_CONFIG is enabled. It is the compressed .config stored
in binary form. Because I'm changing the name of symbols, replacing a
menu with a menuconfig, additional text makes it to .config and the
"# Networking" section in .config disappears.

Here is the diff for the 5 defconfigs listed above, generated with:

for f in build/*-m; do
	diff --unified=0 $f/.config $(dirname $f)/$(basename -a -s '-m' $f)/.config
done

(-m is the build directory for master, and without the suffix, it's the
top commit of this series)

"""
 --- build/opos6uldev-m/.config	2026-04-20 10:53:49.804528526 +0200
 +++ build/opos6uldev/.config	2026-04-20 11:03:37.430242767 +0200
 @@ -970,4 +969,0 @@
 -
 -#
 -# Networking
 -#
 @@ -975,0 +972 @@
 +CONFIG_NET_LEGACY=y
 --- build/stemmy-m/.config	2026-04-20 11:01:33.653698123 +0200
 +++ build/stemmy/.config	2026-04-20 11:04:53.452577311 +0200
 @@ -733,4 +732,0 @@
 -
 -#
 -# Networking
 -#
 @@ -738,2 +733,0 @@
 -# CONFIG_NET is not set
 -# CONFIG_NET_LWIP is not set
 --- build/uniphier_ld4_sld8-m/.config	2026-04-20 11:00:41.605469071 +0200
 +++ build/uniphier_ld4_sld8/.config	2026-04-20 11:04:22.226439899 +0200
 @@ -997,4 +996,0 @@
 -
 -#
 -# Networking
 -#
 @@ -1002,0 +999 @@
 +CONFIG_NET_LEGACY=y
 --- build/uniphier_v7-m/.config	2026-04-20 10:53:04.019307319 +0200
 +++ build/uniphier_v7/.config	2026-04-20 11:03:01.688085486 +0200
 @@ -1004,4 +1003,0 @@
 -
 -#
 -# Networking
 -#
 @@ -1009,0 +1006 @@
 +CONFIG_NET_LEGACY=y
 --- build/uniphier_v8-m/.config	2026-04-20 10:43:05.614441175 +0200
 +++ build/uniphier_v8/.config	2026-04-20 10:41:03.214852130 +0200
 @@ -875,4 +874,0 @@
 -
 -#
 -# Networking
 -#
 @@ -880,0 +877 @@
 +CONFIG_NET_LEGACY=y
"""

This is fine:
- Networking menu doesn't exist anymore so "#\n# Networking\n#\n" won't
  be in .config anymore.
- opos6uldev, uniphier_ld4_sld8, uniphier_v7 and uniphier_v8 all have
  (old) CONFIG_NET enabled, (new) CONFIG_NET will still be set but
  CONFIG_NET_LEGACY also needs to be defined now to reflect the stack
  choice (even if default),
- stemmy has CONFIG_NO_NET set, which means CONFIG_NET and
  CONFIG_NET_LWIP are not reachable anymore hence why they don't need to
  be part of .config,

GitLab CI was run on this series (well, not exactly, but it's only
changes to the git logs that were made):
https://source.denx.de/u-boot/contributors/qschulz/u-boot/-/pipelines/29849

It passes.

Link: https://lore.kernel.org/r/[email protected]

7 files changed, 10 insertions, 10 deletions

diff --git a/include/configs/stm32mp15_common.h b/include/configs/stm32mp15_common.h
index 9cac31bcf47..9a87b479176 100644
--- a/include/configs/stm32mp15_common.h
+++ b/include/configs/stm32mp15_common.h
@@ -41,7 +41,7 @@
 #define BOOT_TARGET_MMC2(func)
 #endif
 
-#ifdef CONFIG_NET
+#ifdef CONFIG_NET_LEGACY
 #define BOOT_TARGET_PXE(func)	func(PXE, pxe, na)
 #else
 #define BOOT_TARGET_PXE(func)
diff --git a/include/configs/stm32mp23_common.h b/include/configs/stm32mp23_common.h
index 7285886b822..392d779ec16 100644
--- a/include/configs/stm32mp23_common.h
+++ b/include/configs/stm32mp23_common.h
@@ -29,7 +29,7 @@
 #ifdef CONFIG_DISTRO_DEFAULTS
 /*****************************************************************************/
 
-#ifdef CONFIG_NET
+#ifdef CONFIG_NET_LEGACY
 #define BOOT_TARGET_PXE(func)	func(PXE, pxe, na)
 #else
 #define BOOT_TARGET_PXE(func)
diff --git a/include/configs/stm32mp25_common.h b/include/configs/stm32mp25_common.h
index b42316fd8ac..a334b47b555 100644
--- a/include/configs/stm32mp25_common.h
+++ b/include/configs/stm32mp25_common.h
@@ -25,7 +25,7 @@
 #ifdef CONFIG_DISTRO_DEFAULTS
 /*****************************************************************************/
 
-#ifdef CONFIG_NET
+#ifdef CONFIG_NET_LEGACY
 #define BOOT_TARGET_PXE(func)	func(PXE, pxe, na)
 #else
 #define BOOT_TARGET_PXE(func)
diff --git a/include/env_callback.h b/include/env_callback.h
index 918ccb3b14f..1181ab4a157 100644
--- a/include/env_callback.h
+++ b/include/env_callback.h
@@ -32,7 +32,7 @@
 #define DNS_CALLBACK
 #endif
 
-#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
+#if CONFIG_IS_ENABLED(NET)
 #define NET_CALLBACKS \
 	"bootfile:bootfile," \
 	"ipaddr:ipaddr," \
diff --git a/include/env_flags.h b/include/env_flags.h
index 0c48874690f..123fdbcb0ba 100644
--- a/include/env_flags.h
+++ b/include/env_flags.h
@@ -14,7 +14,7 @@ enum env_flags_vartype {
 	env_flags_vartype_decimal,
 	env_flags_vartype_hex,
 	env_flags_vartype_bool,
-#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
+#if CONFIG_IS_ENABLED(NET)
 	env_flags_vartype_ipaddr,
 	env_flags_vartype_macaddr,
 #endif
@@ -41,7 +41,7 @@ enum env_flags_varaccess {
 #define CFG_ENV_FLAGS_LIST_STATIC ""
 #endif
 
-#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
+#if CONFIG_IS_ENABLED(NET)
 #ifdef CONFIG_REGEX
 #define ETHADDR_WILDCARD "\\d*"
 #else
@@ -123,7 +123,7 @@ enum env_flags_varaccess env_flags_parse_varaccess(const char *flags);
  */
 enum env_flags_varaccess env_flags_parse_varaccess_from_binflags(int binflags);
 
-#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
+#if CONFIG_IS_ENABLED(NET)
 /*
  * Check if a string has the format of an Ethernet MAC address
  */
diff --git a/include/net-common.h b/include/net-common.h
index f293b21bc0b..69b6316c1ec 100644
--- a/include/net-common.h
+++ b/include/net-common.h
@@ -235,7 +235,7 @@ int eth_rx(void);			/* Check for received packets */
  */
 void reset_phy(void);
 
-#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
+#if CONFIG_IS_ENABLED(NET)
 /**
  * eth_set_enable_bootdevs() - Enable or disable binding of Ethernet bootdevs
  *
@@ -485,7 +485,7 @@ int net_init(void);
 /* Called when a network operation fails to know if it should be re-tried */
 int net_start_again(void);
 
-/* NET compatibility */
+/* NET_LEGACY compatibility */
 enum proto_t;
 int net_loop(enum proto_t protocol);
 
diff --git a/include/net-legacy.h b/include/net-legacy.h
index d489c2480cd..d3b122c9062 100644
--- a/include/net-legacy.h
+++ b/include/net-legacy.h
@@ -281,7 +281,7 @@ extern struct in_addr net_dns_server2;
 #endif
 extern char	net_nis_domain[32];	/* Our IS domain */
 extern char	net_hostname[32];	/* Our hostname */
-#ifdef CONFIG_NET
+#ifdef CONFIG_NET_LEGACY
 extern char	net_root_path[CONFIG_BOOTP_MAX_ROOT_PATH_LEN];	/* Our root path */
 #endif
 /** END OF BOOTP EXTENTIONS **/