kernel: only optimized for size if small_flash

Add a new config option to allow to select the default compile
optimization level for the kernel.

Select the optimization for size by default if the small_flash feature is
set. Otherwise "Optimize for performance" is set.

Add the small_flash feature flag to all (sub)targets which had the
optimization for size in their default kernel config.

Remove CC_OPTIMIZE_FOR_* symbols from all kernel configs to apply the new
setting.

Exceptions to the above are:

  - lantiq, where the optimization for size is only required for the
    xway_legacy subtarget but was set for the whole target
  - mediatek, ramips/mt7620 & ramips/mt76x8 where boards should have
    plenty of space and an optimization for size doesn't make much sense
  - rb532, which has 128MByte flash

Signed-off-by: Mathias Kresin <dev@kresin.me>

8 files changed, 3 insertions, 12 deletions

diff --git a/target/linux/ramips/mt7620/config-4.14 b/target/linux/ramips/mt7620/config-4.14
index d60696b225..89de071446 100644
--- a/target/linux/ramips/mt7620/config-4.14
+++ b/target/linux/ramips/mt7620/config-4.14
@@ -22,8 +22,6 @@ CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_AT803X_PHY=y
 CONFIG_BLK_MQ_PCI=y
-# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
-CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CEVT_R4K=y
 CONFIG_CEVT_SYSTICK_QUIRK=y
 CONFIG_CLKDEV_LOOKUP=y
diff --git a/target/linux/ramips/mt76x8/config-4.14 b/target/linux/ramips/mt76x8/config-4.14
index 614c366d1e..81e0848931 100644
--- a/target/linux/ramips/mt76x8/config-4.14
+++ b/target/linux/ramips/mt76x8/config-4.14
@@ -22,8 +22,6 @@ CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_AT803X_PHY=y
 CONFIG_BLK_MQ_PCI=y
-# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
-CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CEVT_R4K=y
 CONFIG_CEVT_SYSTICK_QUIRK=y
 CONFIG_CLKDEV_LOOKUP=y
diff --git a/target/linux/ramips/rt288x/config-4.14 b/target/linux/ramips/rt288x/config-4.14
index a4b49790a3..de4dffe885 100644
--- a/target/linux/ramips/rt288x/config-4.14
+++ b/target/linux/ramips/rt288x/config-4.14
@@ -21,8 +21,6 @@ CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
 CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_BLK_MQ_PCI=y
-# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
-CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CEVT_R4K=y
 # CONFIG_CEVT_SYSTICK_QUIRK is not set
 CONFIG_CLKDEV_LOOKUP=y
diff --git a/target/linux/ramips/rt288x/target.mk b/target/linux/ramips/rt288x/target.mk
index 2ca5ecfbb3..11b5a0b520 100644
--- a/target/linux/ramips/rt288x/target.mk
+++ b/target/linux/ramips/rt288x/target.mk
@@ -4,6 +4,7 @@
 
 SUBTARGET:=rt288x
 BOARDNAME:=RT288x based boards
+FEATURES+=small_flash
 CPU_TYPE:=24kc
 
 DEFAULT_PACKAGES += kmod-rt2800-soc wpad-mini
diff --git a/target/linux/ramips/rt305x/config-4.14 b/target/linux/ramips/rt305x/config-4.14
index dadf88e032..346a8a8814 100644
--- a/target/linux/ramips/rt305x/config-4.14
+++ b/target/linux/ramips/rt305x/config-4.14
@@ -12,8 +12,6 @@ CONFIG_ARCH_SUPPORTS_UPROBES=y
 CONFIG_ARCH_SUSPEND_POSSIBLE=y
 CONFIG_ARCH_USE_BUILTIN_BSWAP=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
-# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
-CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CEVT_R4K=y
 CONFIG_CEVT_SYSTICK_QUIRK=y
 CONFIG_CLKDEV_LOOKUP=y
diff --git a/target/linux/ramips/rt305x/target.mk b/target/linux/ramips/rt305x/target.mk
index 300639fa38..e36fa637b1 100644
--- a/target/linux/ramips/rt305x/target.mk
+++ b/target/linux/ramips/rt305x/target.mk
@@ -4,7 +4,7 @@
 
 SUBTARGET:=rt305x
 BOARDNAME:=RT3x5x/RT5350 based boards
-FEATURES+=usb ramdisk
+FEATURES+=usb ramdisk small_flash
 CPU_TYPE:=24kc
 
 DEFAULT_PACKAGES += kmod-rt2800-soc wpad-mini
diff --git a/target/linux/ramips/rt3883/config-4.14 b/target/linux/ramips/rt3883/config-4.14
index f663d49865..93d803e2ed 100644
--- a/target/linux/ramips/rt3883/config-4.14
+++ b/target/linux/ramips/rt3883/config-4.14
@@ -22,8 +22,6 @@ CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
 CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 CONFIG_BLK_MQ_PCI=y
-# CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
-CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CEVT_R4K=y
 # CONFIG_CEVT_SYSTICK_QUIRK is not set
 CONFIG_CLKDEV_LOOKUP=y
diff --git a/target/linux/ramips/rt3883/target.mk b/target/linux/ramips/rt3883/target.mk
index a2631d1ac7..2cc19858e4 100644
--- a/target/linux/ramips/rt3883/target.mk
+++ b/target/linux/ramips/rt3883/target.mk
@@ -4,7 +4,7 @@
 
 SUBTARGET:=rt3883
 BOARDNAME:=RT3662/RT3883 based boards
-FEATURES+=usb pci
+FEATURES+=usb pci small_flash
 CPU_TYPE:=74kc
 
 DEFAULT_PACKAGES += kmod-rt2800-pci kmod-rt2800-soc wpad-mini