[LEDE-DEV] [PATCH] cns3xxx: bump SPI partition map kernel size to 2MB

[Tim Harvey]

The 4.4 kernel is not easily sized down to below the 1.5MB limit imposed by
the SPI flash MTD partition mapping. Increase this to 2MB where it is for
NOR flash devices. Additionally add a check that ensures the kernel fits
within the 2MB limit.

This resolves boot issues on SPI based boards such as the GW2380/82.

Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 .../linux/cns3xxx/files/arch/arm/mach-cns3xxx/laguna.c   | 16 ++++++++--------
 target/linux/cns3xxx/image/Makefile                      |  6 +++++-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/target/linux/cns3xxx/files/arch/arm/mach-cns3xxx/laguna.c b/target/linux/cns3xxx/files/arch/arm/mach-cns3xxx/laguna.c
index 667a8e5..f1a0696 100644
--- a/target/linux/cns3xxx/files/arch/arm/mach-cns3xxx/laguna.c
+++ b/target/linux/cns3xxx/files/arch/arm/mach-cns3xxx/laguna.c
@@ -168,12 +168,12 @@ static struct mtd_partition laguna_spi_partitions[] = {
 		.offset		= SZ_256K,
 	}, {
 		.name		= "kernel",
-		.size		= SZ_1M + SZ_512K,
+		.size		= SZ_2M,
 		.offset		= SZ_512K,
 	}, {
 		.name		= "rootfs",
-		.size		= SZ_16M - SZ_2M,
-		.offset		= SZ_2M,
+		.size		= SZ_16M - SZ_2M - SZ_512K,
+		.offset		= SZ_2M + SZ_512K,
 	},
 };
 
@@ -973,19 +973,19 @@ static int __init laguna_model_setup(void)
 		if (laguna_info.config2_bitmap & (SPI_FLASH_LOAD)) {
 			switch (laguna_info.spi_flash_size) {
 				case 1:
-					laguna_spi_partitions[3].size = SZ_4M - SZ_2M;
+					laguna_spi_partitions[3].size = SZ_4M - SZ_2M - SZ_512K;
 				break;
 				case 2:
-					laguna_spi_partitions[3].size = SZ_8M - SZ_2M;
+					laguna_spi_partitions[3].size = SZ_8M - SZ_2M - SZ_512K;
 				break;
 				case 3:
-					laguna_spi_partitions[3].size = SZ_16M - SZ_2M;
+					laguna_spi_partitions[3].size = SZ_16M - SZ_2M - SZ_512K;
 				break;
 				case 4:
-					laguna_spi_partitions[3].size = SZ_32M - SZ_2M;
+					laguna_spi_partitions[3].size = SZ_32M - SZ_2M - SZ_512K;
 				break;
 				case 5:
-					laguna_spi_partitions[3].size = SZ_64M - SZ_2M;
+					laguna_spi_partitions[3].size = SZ_64M - SZ_2M - SZ_512K;
 				break;
 			}
 			spi_register_board_info(ARRAY_AND_SIZE(laguna_spi_devices));
diff --git a/target/linux/cns3xxx/image/Makefile b/target/linux/cns3xxx/image/Makefile
index 8f29c6c..d71a860 100644
--- a/target/linux/cns3xxx/image/Makefile
+++ b/target/linux/cns3xxx/image/Makefile
@@ -9,6 +9,10 @@ include $(INCLUDE_DIR)/image.mk
 
 define Image/Prepare
 	mkimage -A arm -O linux -T kernel -C none -a 0x20008000 -e 0x20008000 -n 'OpenWrt Linux-$(LINUX_VERSION)' -d $(KDIR)/zImage $(KDIR)/uImage
+	@if [ `stat -c%s "$(KDIR)/uImage"` -gt `expr 2048 \* 1024` ]; then \
+		echo "Error: Kernel is too big" >&2; \
+		exit 1; \
+	fi
 endef
 
 # Build sysupgrade image
@@ -39,7 +43,7 @@ define Image/Build/squashfs
 	dd if=$(KDIR)/root.$(1) bs=128k conv=sync; \
 	) > $(BIN_DIR)/$(IMG_PREFIX)-$(1)_laguna_nor.bin
 	( \
-	dd if=$(KDIR)/uImage bs=1536k conv=sync; \
+	dd if=$(KDIR)/uImage bs=2048k conv=sync; \
 	dd if=$(KDIR)/root.$(1) bs=256k conv=sync; \
 	) > $(BIN_DIR)/$(IMG_PREFIX)-$(1)_laguna_spi.bin
 endef
-- 
1.9.1