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Commit 6afd6fae authored by Hyok S. Choi's avatar Hyok S. Choi Committed by Russell King
Browse files

[ARM] nommu: confirms the CR_V bit in nommu mode 



In nommu mode, the exception vector location depends on the platforms.
Some of the implementations may have some special exception control
forwarding method in their ROM/flash and for some of them has its own
re-mapping mechanism by the h/w.

This patch introduces a special configuration CONFIG_CPU_HIGH_VECTOR which
turns on the CR_V bit in nommu mode. The CR_V bit is turned off by default.
This feature depends on CP15 and does not supported by ARM740.

Signed-off-by: default avatarHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 0f45d7f3

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ config ARCH_MTD_XIP 


config VECTORS_BASE

	hex

	default 0xffff0000 if MMU

	default 0xffff0000 if MMU || CPU_HIGH_VECTOR

	default DRAM_BASE if REMAP_VECTORS_TO_RAM

	default 0x00000000

	help

arch/arm/kernel/head-nommu.S

+5 −0
Original line number Diff line number Diff line
@@ -76,6 +76,11 @@ __after_proc_init: 
#endif

#ifdef CONFIG_CPU_ICACHE_DISABLE

	bic	r0, r0, #CR_I

#endif

#ifdef CONFIG_CPU_HIGH_VECTOR

	orr	r0, r0, #CR_V

#else

	bic	r0, r0, #CR_V

#endif

	mcr	p15, 0, r0, c1, c0, 0		@ write control reg

#endif /* CONFIG_CPU_CP15 */

arch/arm/mm/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -524,6 +524,18 @@ config CPU_BIG_ENDIAN 
	  port must properly enable any big-endian related features

	  of your chipset/board/processor.



config CPU_HIGH_VECTOR

	depends !MMU && CPU_CP15 && !CPU_ARM740T

	bool "Select the High exception vector"

	default n

	help

	  Say Y here to select high exception vector(0xFFFF0000~).

	  The exception vector can be vary depending on the platform

	  design in nommu mode. If your platform needs to select

	  high exception vector, say Y.

	  Otherwise or if you are unsure, say N, and the low exception

	  vector (0x00000000~) will be used.



config CPU_ICACHE_DISABLE

	bool "Disable I-Cache (I-bit)"

	depends on CPU_CP15 && !(CPU_ARM610 || CPU_ARM710 || CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)