[BUG] boot fail with ARM_LPAE and VMSPLIT_3G_OPT

From: Yisheng Xie
Date: Tue Jun 06 2017 - 07:09:52 EST


Hi all,

I find when both enable CONFIG_ARM_LPAE=y and CONFIG_VMSPLIT_3G_OPT=y,
which mean use PAGE_OFFSET=0xB0000000 with ARM_LPE, the kernel will boot fail.
it stop after uncompressed:
--------
Starting kernel ...

Uart base = 0x20001000
watchdog reg = 0x20013000
dtb addr = 0x80840308
Uncompressing Linux... done, booting the kernel.

--------

Meanwhile, I also tried to use CONFIG_VMSPLIT_2G/CONFIG_VMSPLIT_1G with ARM_LPAE,
it can boot successfully.

Is that a limitation of ARM_LPAE, which I not do get any info about this from spec?
If it do have the limitation, then we should be:
--------
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4c1a35f..c0fcab6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1416,6 +1416,7 @@ choice
config VMSPLIT_3G
bool "3G/1G user/kernel split"
config VMSPLIT_3G_OPT
+ depends on !ARM_LPAE
bool "3G/1G user/kernel split (for full 1G low memory)"
config VMSPLIT_2G
bool "2G/2G user/kernel split"



Any comment is more than welcome!

Thanks
Yisheng Xie