[meta-xilinx] [PATCH] linux/config: For Zynq hard disable CONFIG_DEBUG_RODATA

[Nathan Rossi]

CONFIG_DEBUG_RODATA was switched to default yes in v4.6+ kernels. Whilst
the feature works correctly it causes changes with how the kernel
.head.text and .text sections are padded which allows for memory below
0x80000 (512KB) to be non-reserved and used as memory for DMA
allocations which do not work on Zynq due to devices not being allowed
to access DDR below 0x80000. Disabling CONFIG_DEBUG_RODATA prevents the
padding between .head.text/.text.

Signed-off-by: Nathan Rossi <nathan at nathanrossi.com>
---
 recipes-kernel/linux/config/xilinx-common/bsp/xilinx/soc/zynq7.cfg | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/recipes-kernel/linux/config/xilinx-common/bsp/xilinx/soc/zynq7.cfg b/recipes-kernel/linux/config/xilinx-common/bsp/xilinx/soc/zynq7.cfg
index 935848758c..b6dc0dbd6e 100644
--- a/recipes-kernel/linux/config/xilinx-common/bsp/xilinx/soc/zynq7.cfg
+++ b/recipes-kernel/linux/config/xilinx-common/bsp/xilinx/soc/zynq7.cfg
@@ -40,3 +40,6 @@ CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
 CONFIG_CPU_IDLE=y
 CONFIG_ARM_ZYNQ_CPUIDLE=y
 
+# DEBUG_RODATA causes issues with the lower 512KB of memory which doesn't do DMA
+# CONFIG_DEBUG_RODATA is not set
+
-- 
2.10.2