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, 12 insertions, 12 deletions

diff --git a/drivers/dfu/Kconfig b/drivers/dfu/Kconfig
index 962bda40ad2..eeae2fd65ad 100644
--- a/drivers/dfu/Kconfig
+++ b/drivers/dfu/Kconfig
@@ -11,7 +11,7 @@ config DFU_OVER_USB
 
 config DFU_OVER_TFTP
 	bool
-	depends on NET
+	depends on NET_LEGACY
 
 config DFU_WRITE_ALT
 	bool
diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
index 576c3ef8a45..90212fcf9ef 100644
--- a/drivers/fastboot/Kconfig
+++ b/drivers/fastboot/Kconfig
@@ -27,7 +27,7 @@ config USB_FUNCTION_FASTBOOT
 	  This enables the USB part of the fastboot gadget.
 
 config UDP_FUNCTION_FASTBOOT
-	depends on NET
+	depends on NET_LEGACY
 	select FASTBOOT
 	bool "Enable fastboot protocol over UDP"
 	help
@@ -41,7 +41,7 @@ config UDP_FUNCTION_FASTBOOT_PORT
 	  The fastboot protocol requires a UDP port number.
 
 config TCP_FUNCTION_FASTBOOT
-	depends on NET
+	depends on NET_LEGACY
 	select FASTBOOT
 	bool "Enable fastboot protocol over TCP"
 	help
diff --git a/drivers/fastboot/fb_common.c b/drivers/fastboot/fb_common.c
index dac5528f809..9c52e004588 100644
--- a/drivers/fastboot/fb_common.c
+++ b/drivers/fastboot/fb_common.c
@@ -191,13 +191,13 @@ void fastboot_handle_boot(int command, bool success)
 	switch (command) {
 	case FASTBOOT_COMMAND_BOOT:
 		fastboot_boot();
-#if CONFIG_IS_ENABLED(NET)
+#if CONFIG_IS_ENABLED(NET_LEGACY)
 		net_set_state(NETLOOP_SUCCESS);
 #endif
 		break;
 
 	case FASTBOOT_COMMAND_CONTINUE:
-#if CONFIG_IS_ENABLED(NET)
+#if CONFIG_IS_ENABLED(NET_LEGACY)
 		net_set_state(NETLOOP_SUCCESS);
 #endif
 		break;
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ed07e286676..666618681df 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -339,7 +339,7 @@ config ESSEDMA
 
 config ETH_SANDBOX
 	depends on SANDBOX
-	depends on NET || NET_LWIP
+	depends on NET
 	default y
 	bool "Sandbox: Mocked Ethernet driver"
 	help
@@ -350,7 +350,7 @@ config ETH_SANDBOX
 
 config ETH_SANDBOX_RAW
 	depends on SANDBOX
-	depends on NET
+	depends on NET_LEGACY
 	default y
 	bool "Sandbox: Bridge to Linux Raw Sockets"
 	help
@@ -476,7 +476,7 @@ config FTMAC100
 config FTGMAC100
 	bool "Ftgmac100 Ethernet Support"
 	select PHYLIB
-	depends on NET
+	depends on NET_LEGACY
 	help
 	  This driver supports the Faraday's FTGMAC100 Gigabit SoC
 	  Ethernet controller that can be found on Aspeed SoCs (which
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 5d2277a4602..0025c895f12 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -7,7 +7,7 @@ config MV88E6352_SWITCH
 
 menuconfig PHYLIB
 	bool "Ethernet PHY (physical media interface) support"
-	depends on NET || NET_LWIP
+	depends on NET
 	help
 	  Enable Ethernet PHY (physical media interface) support.
 
@@ -381,7 +381,7 @@ config PHY_FIXED
 
 config PHY_NCSI
 	bool "NC-SI based PHY"
-	depends on NET
+	depends on NET_LEGACY
 
 endif #PHYLIB
 
diff --git a/drivers/net/sandbox.c b/drivers/net/sandbox.c
index 0ea50c484c0..e1daeb6c1e6 100644
--- a/drivers/net/sandbox.c
+++ b/drivers/net/sandbox.c
@@ -15,7 +15,7 @@
 
 /*
  * Structure definitions for network protocols. Since this file is used for
- * both NET and NET_LWIP, and given that the two network stacks do have
+ * both NET_LEGACY and NET_LWIP, and given that the two network stacks do have
  * conflicting types (for instance struct icmp_hdr), it is on purpose that the
  * structures are defined locally with minimal dependencies -- <asm/types.h> is
  * included for the bit types and that's it.
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index baa2eb61ea3..18582962249 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -232,7 +232,7 @@ endif # USB_GADGET_DOWNLOAD
 
 config USB_ETHER
 	bool "USB Ethernet Gadget"
-	depends on NET || NET_LWIP
+	depends on NET
 	default y if ARCH_SUNXI && USB_MUSB_GADGET
 	help
 	  Creates an Ethernet network device through a USB peripheral