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#include <linux/linkage.h>
#include <init.h>
#include <asm/system.h>
.section ".text_bare_init_","ax"
ENTRY(arm_cpu_lowlevel_init)
/* save lr, since it may be banked away with a processor mode change */
mov r2, lr
/* set the cpu to SVC32 mode, mask irq and fiq */
mrs r12, cpsr
bic r12, r12, #0x1f
orr r12, r12, #0xd3
msr cpsr, r12
#if __LINUX_ARM_ARCH__ >= 6
/*
* ICIALLU: Invalidate all instruction caches to PoU,
* includes flushing of branch predictors.
* Even if the i-cache is off it might contain stale entries
* that are better discarded before enabling the cache.
* Architectually this is even possible after a cold reset.
*/
mcr p15, 0, r12, c7, c5, 0
/* DSB, ensure completion of the invalidation */
mcr p15, 0, r12, c7, c10, 4
/*
* ISB, ensure instruction fetch path is in sync.
* Note that the ARM Architecture Reference Manual, ARMv7-A and ARMv7-R
* edition (ARM DDI 0406C.c) doesn't define this instruction in the
* ARMv6 part (D12.7.10). It only has: "Support of additional
* operations is IMPLEMENTATION DEFINED".
* But an earlier version of the ARMARM (ARM DDI 0100I) does define it
* as "Flush prefetch buffer (PrefetchFlush)".
*/
mcr p15, 0, r12, c7, c5, 4
#endif
/* disable MMU stuff and data/unified caches */
mrc p15, 0, r12, c1, c0, 0 /* SCTLR */
bic r12, r12, #(CR_M | CR_C | CR_B)
bic r12, r12, #(CR_S | CR_R | CR_V)
/* enable instruction cache */
orr r12, r12, #CR_I
#if __LINUX_ARM_ARCH__ >= 6
orr r12, r12, #CR_U
bic r12, r12, #CR_A
#else
orr r12, r12, #CR_A
#endif
#ifdef __ARMEB__
orr r12, r12, #CR_B
#endif
mcr p15, 0, r12, c1, c0, 0 /* SCTLR */
mov pc, r2
ENDPROC(arm_cpu_lowlevel_init)
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