[U-Boot] [PATCH v4 26/26] sunxi: A64: add 32-bit SPL support

[Andre Przywara]

When compiling the SPL for the Allwinner A64 in AArch64 mode, we can't
use the more compact Thumb2 encoding, which only exists for AArch32
code. This makes the SPL rather big, up to a point where any code
additions or even a different compiler may easily exceed the 32KB limit
that the Allwinner BROM imposes.
Introduce a separate, mostly generic sun50i-a64 configuration, which
defines the CPU_V7 symbol and thus will create a 32-bit binary using
the memory-saving Thumb2 encoding.
This should only be used for the SPL, the U-Boot proper should still be
using the existing 64-bit configuration. The SPL code can switch to
AArch64 if needed, so a 32-bit SPL can be combined with a 64-bit U-Boot
proper to eventually launch arm64 kernels.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
 board/sunxi/Kconfig            | 14 ++++++++++++--
 configs/pine64_plus_defconfig  |  2 +-
 configs/sun50i_spl32_defconfig | 10 ++++++++++
 3 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 configs/sun50i_spl32_defconfig

diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 0001133..0d77c3a 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -43,6 +43,10 @@ config SUNXI_GEN_SUN6I
 	watchdog, etc.
 
 
+config MACH_SUN50I
+	bool
+	select SUNXI_GEN_SUN6I
+
 choice
 	prompt "Sunxi SoC Variant"
 	optional
@@ -121,10 +125,16 @@ config MACH_SUN9I
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
 
-config MACH_SUN50I
+config MACH_SUN50I_64
 	bool "sun50i (Allwinner A64)"
+	select MACH_SUN50I
 	select ARM64
-	select SUNXI_GEN_SUN6I
+	select SUPPORT_SPL
+
+config MACH_SUN50I_32
+	bool "sun50i (Allwinner A64) SPL-32bit"
+	select MACH_SUN50I
+	select CPU_V7
 	select SUPPORT_SPL
 
 endchoice
diff --git a/configs/pine64_plus_defconfig b/configs/pine64_plus_defconfig
index 2374170..a76f66a 100644
--- a/configs/pine64_plus_defconfig
+++ b/configs/pine64_plus_defconfig
@@ -1,7 +1,7 @@
 CONFIG_ARM=y
 CONFIG_RESERVE_ALLWINNER_BOOT0_HEADER=y
 CONFIG_ARCH_SUNXI=y
-CONFIG_MACH_SUN50I=y
+CONFIG_MACH_SUN50I_64=y
 CONFIG_DEFAULT_DEVICE_TREE="sun50i-a64-pine64-plus"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_CONSOLE_MUX=y
diff --git a/configs/sun50i_spl32_defconfig b/configs/sun50i_spl32_defconfig
new file mode 100644
index 0000000..29c6a47
--- /dev/null
+++ b/configs/sun50i_spl32_defconfig
@@ -0,0 +1,10 @@
+CONFIG_ARM=y
+CONFIG_ARCH_SUNXI=y
+CONFIG_MACH_SUN50I_32=y
+CONFIG_SPL=y
+CONFIG_DEFAULT_DEVICE_TREE="sun50i-a64-pine64-plus"
+CONFIG_OF_LIST="sun50i-a64-pine64 sun50i-a64-pine64-plus"
+# CONFIG_CMD_IMLS is not set
+# CONFIG_CMD_FLASH is not set
+# CONFIG_CMD_FPGA is not set
+CONFIG_MMC_SUNXI_SLOT_EXTRA=2
-- 
2.8.2