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mmu-arm.S: disable MMU functions on CPUs which don't use them

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25629 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Rafaël Carré 2010-04-13 15:17:08 +00:00
parent 4205a508d7
commit 96e97987d9
1 changed files with 28 additions and 12 deletions
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40
firmware/target/arm/mmu-arm.S
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@ -24,16 +24,26 @@
/* Used by ARMv4 & ARMv5 CPUs with cp15 register and MMU */
/* WARNING : assume size of a data cache line == 32 bytes */
#if CONFIG_CPU == TCC7801 || CONFIG_CPU == AT91SAM9260 \
|| CONFIG_CPU == DM320 || CONFIG_CPU == AS3525v2
#if CONFIG_CPU == TCC7801 || CONFIG_CPU == AT91SAM9260
/* MMU present but unused */
#define HAVE_TEST_AND_CLEAN_CACHE
#elif CONFIG_CPU == DM320 || CONFIG_CPU == AS3525v2
#define USE_MMU
#define HAVE_TEST_AND_CLEAN_CACHE
#elif CONFIG_CPU == AS3525
#define USE_MMU
#define CACHE_SIZE 8
#elif CONFIG_CPU == S3C2440
#define USE_MMU
#define CACHE_SIZE 16
#else
#error Cache settings unknown for this CPU !
#endif
#endif /* CPU specific configuration */
@ Index format: 31:26 = index, N:5 = segment, remainder = SBZ
@ assume 64-way set associative separate I/D caches, 32B (2^5) cache line size
@ -45,6 +55,8 @@
#define INDEX_STEPS (CACHE_SIZE/2)
#ifdef USE_MMU
/** MMU setup **/
/*
@ -80,18 +92,18 @@ map_section:
@ 10: superuser - r/w, user - no access
@ 4: should be "1"
@ 3,2: Cache flags (flags (r3))
@ 1: Section signature
@ 1: Section signature
orr r0, r0, r3
orr r0, r0, #0x410
orr r0, r0, #0x2
@ unsigned int* ttbPtr = TTB_BASE + (va >> 20);
@ sections are 1MB size
@ sections are 1MB size
mov r1, r1, lsr #20
ldr r3, =TTB_BASE_ADDR
add r1, r3, r1, lsl #0x2
@ Add MB to pa, flags are already present in pa, but addition
add r1, r3, r1, lsl #0x2
@ Add MB to pa, flags are already present in pa, but addition
@ should not effect them
@
@ for( ; mb>0; mb--, pa += (1 << 20))
@ -133,7 +145,11 @@ enable_mmu:
bx lr @
.size enable_mmu, .-enable_mmu
.ltorg
#endif /* USE_MMU */
/** Cache coherency **/
/*
@ -315,7 +331,7 @@ cpucache_flush:
bne 1b @ clean_start @
#endif /* HAVE_TEST_AND_CLEAN_CACHE */
mcr p15, 0, r1, c7, c10, 4 @ Drain write buffer
bx lr @
bx lr @
.size clean_dcache, .-clean_dcache
/*
@ -362,7 +378,7 @@ invalidate_dcache:
.type invalidate_idcache, %function
.global cpucache_invalidate @ Alias
invalidate_idcache:
cpucache_invalidate:
cpucache_invalidate:
mov r2, lr @ save lr to r1, call uses r0 only
bl invalidate_dcache @ Clean and invalidate entire DCache
mcr p15, 0, r1, c7, c5, 0 @ Invalidate ICache (r1=0 from call)