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head.S
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head.S
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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/boot/compressed/head.S
*
* Copyright (C) 1996-2002 Russell King
* Copyright (C) 2004 Hyok S. Choi (MPU support)
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/v7m.h>
#include "efi-header.S"
AR_CLASS( .arch armv7-a )
M_CLASS( .arch armv7-m )
/*
* Debugging stuff
*
* Note that these macros must not contain any code which is not
* 100% relocatable. Any attempt to do so will result in a crash.
* Please select one of the following when turning on debugging.
*/
#ifdef DEBUG
#if defined(CONFIG_DEBUG_ICEDCC)
#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c0, c5, 0
.endm
#elif defined(CONFIG_CPU_XSCALE)
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c8, c0, 0
.endm
#else
.macro loadsp, rb, tmp1, tmp2
.endm
.macro writeb, ch, rb
mcr p14, 0, \ch, c1, c0, 0
.endm
#endif
#else
#include CONFIG_DEBUG_LL_INCLUDE
.macro writeb, ch, rb
senduart \ch, \rb
.endm
#if defined(CONFIG_ARCH_SA1100)
.macro loadsp, rb, tmp1, tmp2
mov \rb, #0x80000000 @ physical base address
#ifdef CONFIG_DEBUG_LL_SER3
add \rb, \rb, #0x00050000 @ Ser3
#else
add \rb, \rb, #0x00010000 @ Ser1
#endif
.endm
#else
.macro loadsp, rb, tmp1, tmp2
addruart \rb, \tmp1, \tmp2
.endm
#endif
#endif
#endif
.macro kputc,val
mov r0, \val
bl putc
.endm
.macro kphex,val,len
mov r0, \val
mov r1, #\len
bl phex
.endm
.macro debug_reloc_start
#ifdef DEBUG
kputc #'\n'
kphex r6, 8 /* processor id */
kputc #':'
kphex r7, 8 /* architecture id */
#ifdef CONFIG_CPU_CP15
kputc #':'
mrc p15, 0, r0, c1, c0
kphex r0, 8 /* control reg */
#endif
kputc #'\n'
kphex r5, 8 /* decompressed kernel start */
kputc #'-'
kphex r9, 8 /* decompressed kernel end */
kputc #'>'
kphex r4, 8 /* kernel execution address */
kputc #'\n'
#endif
.endm
.macro debug_reloc_end
#ifdef DEBUG
kphex r5, 8 /* end of kernel */
kputc #'\n'
mov r0, r4
bl memdump /* dump 256 bytes at start of kernel */
#endif
.endm
/*
* Debug kernel copy by printing the memory addresses involved
*/
.macro dbgkc, begin, end, cbegin, cend
#ifdef DEBUG
kputc #'\n'
kputc #'C'
kputc #':'
kputc #'0'
kputc #'x'
kphex \begin, 8 /* Start of compressed kernel */
kputc #'-'
kputc #'0'
kputc #'x'
kphex \end, 8 /* End of compressed kernel */
kputc #'-'
kputc #'>'
kputc #'0'
kputc #'x'
kphex \cbegin, 8 /* Start of kernel copy */
kputc #'-'
kputc #'0'
kputc #'x'
kphex \cend, 8 /* End of kernel copy */
kputc #'\n'
kputc #'\r'
#endif
.endm
.section ".start", #alloc, #execinstr
/*
* sort out different calling conventions
*/
.align
/*
* Always enter in ARM state for CPUs that support the ARM ISA.
* As of today (2014) that's exactly the members of the A and R
* classes.
*/
AR_CLASS( .arm )
start:
.type start,#function
/*
* These 7 nops along with the 1 nop immediately below for
* !THUMB2 form 8 nops that make the compressed kernel bootable
* on legacy ARM systems that were assuming the kernel in a.out
* binary format. The boot loaders on these systems would
* jump 32 bytes into the image to skip the a.out header.
* with these 8 nops filling exactly 32 bytes, things still
* work as expected on these legacy systems. Thumb2 mode keeps
* 7 of the nops as it turns out that some boot loaders
* were patching the initial instructions of the kernel, i.e
* had started to exploit this "patch area".
*/
.rept 7
__nop
.endr
#ifndef CONFIG_THUMB2_KERNEL
__nop
#else
AR_CLASS( sub pc, pc, #3 ) @ A/R: switch to Thumb2 mode
M_CLASS( nop.w ) @ M: already in Thumb2 mode
.thumb
#endif
W(b) 1f
.word _magic_sig @ Magic numbers to help the loader
.word _magic_start @ absolute load/run zImage address
.word _magic_end @ zImage end address
.word 0x04030201 @ endianness flag
.word 0x45454545 @ another magic number to indicate
.word _magic_table @ additional data table
__EFI_HEADER
1:
ARM_BE8( setend be ) @ go BE8 if compiled for BE8
AR_CLASS( mrs r9, cpsr )
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install @ get into SVC mode, reversibly
#endif
mov r7, r1 @ save architecture ID
mov r8, r2 @ save atags pointer
#ifndef CONFIG_CPU_V7M
/*
* Booting from Angel - need to enter SVC mode and disable
* FIQs/IRQs (numeric definitions from angel arm.h source).
* We only do this if we were in user mode on entry.
*/
mrs r2, cpsr @ get current mode
tst r2, #3 @ not user?
bne not_angel
mov r0, #0x17 @ angel_SWIreason_EnterSVC
ARM( swi 0x123456 ) @ angel_SWI_ARM
THUMB( svc 0xab ) @ angel_SWI_THUMB
not_angel:
safe_svcmode_maskall r0
msr spsr_cxsf, r9 @ Save the CPU boot mode in
@ SPSR
#endif
/*
* Note that some cache flushing and other stuff may
* be needed here - is there an Angel SWI call for this?
*/
/*
* some architecture specific code can be inserted
* by the linker here, but it should preserve r7, r8, and r9.
*/
.text
#ifdef CONFIG_AUTO_ZRELADDR
/*
* Find the start of physical memory. As we are executing
* without the MMU on, we are in the physical address space.
* We just need to get rid of any offset by aligning the
* address.
*
* This alignment is a balance between the requirements of
* different platforms - we have chosen 128MB to allow
* platforms which align the start of their physical memory
* to 128MB to use this feature, while allowing the zImage
* to be placed within the first 128MB of memory on other
* platforms. Increasing the alignment means we place
* stricter alignment requirements on the start of physical
* memory, but relaxing it means that we break people who
* are already placing their zImage in (eg) the top 64MB
* of this range.
*/
mov r4, pc
and r4, r4, #0xf8000000
/* Determine final kernel image address. */
add r4, r4, #TEXT_OFFSET
#else
ldr r4, =zreladdr
#endif
/*
* Set up a page table only if it won't overwrite ourself.
* That means r4 < pc || r4 - 16k page directory > &_end.
* Given that r4 > &_end is most unfrequent, we add a rough
* additional 1MB of room for a possible appended DTB.
*/
mov r0, pc
cmp r0, r4
ldrcc r0, LC0+32
addcc r0, r0, pc
cmpcc r4, r0
orrcc r4, r4, #1 @ remember we skipped cache_on
blcs cache_on
restart: adr r0, LC0
ldmia r0, {r1, r2, r3, r6, r10, r11, r12}
ldr sp, [r0, #28]
/*
* We might be running at a different address. We need
* to fix up various pointers.
*/
sub r0, r0, r1 @ calculate the delta offset
add r6, r6, r0 @ _edata
add r10, r10, r0 @ inflated kernel size location
/*
* The kernel build system appends the size of the
* decompressed kernel at the end of the compressed data
* in little-endian form.
*/
ldrb r9, [r10, #0]
ldrb lr, [r10, #1]
orr r9, r9, lr, lsl #8
ldrb lr, [r10, #2]
ldrb r10, [r10, #3]
orr r9, r9, lr, lsl #16
orr r9, r9, r10, lsl #24
#ifndef CONFIG_ZBOOT_ROM
/* malloc space is above the relocated stack (64k max) */
add sp, sp, r0
add r10, sp, #0x10000
#else
/*
* With ZBOOT_ROM the bss/stack is non relocatable,
* but someone could still run this code from RAM,
* in which case our reference is _edata.
*/
mov r10, r6
#endif
mov r5, #0 @ init dtb size to 0
#ifdef CONFIG_ARM_APPENDED_DTB
/*
* r0 = delta
* r2 = BSS start
* r3 = BSS end
* r4 = final kernel address (possibly with LSB set)
* r5 = appended dtb size (still unknown)
* r6 = _edata
* r7 = architecture ID
* r8 = atags/device tree pointer
* r9 = size of decompressed image
* r10 = end of this image, including bss/stack/malloc space if non XIP
* r11 = GOT start
* r12 = GOT end
* sp = stack pointer
*
* if there are device trees (dtb) appended to zImage, advance r10 so that the
* dtb data will get relocated along with the kernel if necessary.
*/
ldr lr, [r6, #0]
#ifndef __ARMEB__
ldr r1, =0xedfe0dd0 @ sig is 0xd00dfeed big endian
#else
ldr r1, =0xd00dfeed
#endif
cmp lr, r1
bne dtb_check_done @ not found
#ifdef CONFIG_ARM_ATAG_DTB_COMPAT
/*
* OK... Let's do some funky business here.
* If we do have a DTB appended to zImage, and we do have
* an ATAG list around, we want the later to be translated
* and folded into the former here. No GOT fixup has occurred
* yet, but none of the code we're about to call uses any
* global variable.
*/
/* Get the initial DTB size */
ldr r5, [r6, #4]
#ifndef __ARMEB__
/* convert to little endian */
eor r1, r5, r5, ror #16
bic r1, r1, #0x00ff0000
mov r5, r5, ror #8
eor r5, r5, r1, lsr #8
#endif
/* 50% DTB growth should be good enough */
add r5, r5, r5, lsr #1
/* preserve 64-bit alignment */
add r5, r5, #7
bic r5, r5, #7
/* clamp to 32KB min and 1MB max */
cmp r5, #(1 << 15)
movlo r5, #(1 << 15)
cmp r5, #(1 << 20)
movhi r5, #(1 << 20)
/* temporarily relocate the stack past the DTB work space */
add sp, sp, r5
stmfd sp!, {r0-r3, ip, lr}
mov r0, r8
mov r1, r6
mov r2, r5
bl atags_to_fdt
/*
* If returned value is 1, there is no ATAG at the location
* pointed by r8. Try the typical 0x100 offset from start
* of RAM and hope for the best.
*/
cmp r0, #1
sub r0, r4, #TEXT_OFFSET
bic r0, r0, #1
add r0, r0, #0x100
mov r1, r6
mov r2, r5
bleq atags_to_fdt
ldmfd sp!, {r0-r3, ip, lr}
sub sp, sp, r5
#endif
mov r8, r6 @ use the appended device tree
/*
* Make sure that the DTB doesn't end up in the final
* kernel's .bss area. To do so, we adjust the decompressed
* kernel size to compensate if that .bss size is larger
* than the relocated code.
*/
ldr r5, =_kernel_bss_size
adr r1, wont_overwrite
sub r1, r6, r1
subs r1, r5, r1
addhi r9, r9, r1
/* Get the current DTB size */
ldr r5, [r6, #4]
#ifndef __ARMEB__
/* convert r5 (dtb size) to little endian */
eor r1, r5, r5, ror #16
bic r1, r1, #0x00ff0000
mov r5, r5, ror #8
eor r5, r5, r1, lsr #8
#endif
/* preserve 64-bit alignment */
add r5, r5, #7
bic r5, r5, #7
/* relocate some pointers past the appended dtb */
add r6, r6, r5
add r10, r10, r5
add sp, sp, r5
dtb_check_done:
#endif
/*
* Check to see if we will overwrite ourselves.
* r4 = final kernel address (possibly with LSB set)
* r9 = size of decompressed image
* r10 = end of this image, including bss/stack/malloc space if non XIP
* We basically want:
* r4 - 16k page directory >= r10 -> OK
* r4 + image length <= address of wont_overwrite -> OK
* Note: the possible LSB in r4 is harmless here.
*/
add r10, r10, #16384
cmp r4, r10
bhs wont_overwrite
add r10, r4, r9
adr r9, wont_overwrite
cmp r10, r9
bls wont_overwrite
/*
* Relocate ourselves past the end of the decompressed kernel.
* r6 = _edata
* r10 = end of the decompressed kernel
* Because we always copy ahead, we need to do it from the end and go
* backward in case the source and destination overlap.
*/
/*
* Bump to the next 256-byte boundary with the size of
* the relocation code added. This avoids overwriting
* ourself when the offset is small.
*/
add r10, r10, #((reloc_code_end - restart + 256) & ~255)
bic r10, r10, #255
/* Get start of code we want to copy and align it down. */
adr r5, restart
bic r5, r5, #31
/* Relocate the hyp vector base if necessary */
#ifdef CONFIG_ARM_VIRT_EXT
mrs r0, spsr
and r0, r0, #MODE_MASK
cmp r0, #HYP_MODE
bne 1f
/*
* Compute the address of the hyp vectors after relocation.
* This requires some arithmetic since we cannot directly
* reference __hyp_stub_vectors in a PC-relative way.
* Call __hyp_set_vectors with the new address so that we
* can HVC again after the copy.
*/
0: adr r0, 0b
movw r1, #:lower16:__hyp_stub_vectors - 0b
movt r1, #:upper16:__hyp_stub_vectors - 0b
add r0, r0, r1
sub r0, r0, r5
add r0, r0, r10
bl __hyp_set_vectors
1:
#endif
sub r9, r6, r5 @ size to copy
add r9, r9, #31 @ rounded up to a multiple
bic r9, r9, #31 @ ... of 32 bytes
add r6, r9, r5
add r9, r9, r10
#ifdef DEBUG
sub r10, r6, r5
sub r10, r9, r10
/*
* We are about to copy the kernel to a new memory area.
* The boundaries of the new memory area can be found in
* r10 and r9, whilst r5 and r6 contain the boundaries
* of the memory we are going to copy.
* Calling dbgkc will help with the printing of this
* information.
*/
dbgkc r5, r6, r10, r9
#endif
1: ldmdb r6!, {r0 - r3, r10 - r12, lr}
cmp r6, r5
stmdb r9!, {r0 - r3, r10 - r12, lr}
bhi 1b
/* Preserve offset to relocated code. */
sub r6, r9, r6
#ifndef CONFIG_ZBOOT_ROM
/* cache_clean_flush may use the stack, so relocate it */
add sp, sp, r6
#endif
bl cache_clean_flush
badr r0, restart
add r0, r0, r6
mov pc, r0
wont_overwrite:
/*
* If delta is zero, we are running at the address we were linked at.
* r0 = delta
* r2 = BSS start
* r3 = BSS end
* r4 = kernel execution address (possibly with LSB set)
* r5 = appended dtb size (0 if not present)
* r7 = architecture ID
* r8 = atags pointer
* r11 = GOT start
* r12 = GOT end
* sp = stack pointer
*/
orrs r1, r0, r5
beq not_relocated
add r11, r11, r0
add r12, r12, r0
#ifndef CONFIG_ZBOOT_ROM
/*
* If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
* we need to fix up pointers into the BSS region.
* Note that the stack pointer has already been fixed up.
*/
add r2, r2, r0
add r3, r3, r0
/*
* Relocate all entries in the GOT table.
* Bump bss entries to _edata + dtb size
*/
1: ldr r1, [r11, #0] @ relocate entries in the GOT
add r1, r1, r0 @ This fixes up C references
cmp r1, r2 @ if entry >= bss_start &&
cmphs r3, r1 @ bss_end > entry
addhi r1, r1, r5 @ entry += dtb size
str r1, [r11], #4 @ next entry
cmp r11, r12
blo 1b
/* bump our bss pointers too */
add r2, r2, r5
add r3, r3, r5
#else
/*
* Relocate entries in the GOT table. We only relocate
* the entries that are outside the (relocated) BSS region.
*/
1: ldr r1, [r11, #0] @ relocate entries in the GOT
cmp r1, r2 @ entry < bss_start ||
cmphs r3, r1 @ _end < entry
addlo r1, r1, r0 @ table. This fixes up the
str r1, [r11], #4 @ C references.
cmp r11, r12
blo 1b
#endif
not_relocated: mov r0, #0
1: str r0, [r2], #4 @ clear bss
str r0, [r2], #4
str r0, [r2], #4
str r0, [r2], #4
cmp r2, r3
blo 1b
/*
* Did we skip the cache setup earlier?
* That is indicated by the LSB in r4.
* Do it now if so.
*/
tst r4, #1
bic r4, r4, #1
blne cache_on
/*
* The C runtime environment should now be setup sufficiently.
* Set up some pointers, and start decompressing.
* r4 = kernel execution address
* r7 = architecture ID
* r8 = atags pointer
*/
mov r0, r4
mov r1, sp @ malloc space above stack
add r2, sp, #0x10000 @ 64k max
mov r3, r7
bl decompress_kernel
bl cache_clean_flush
bl cache_off
#ifdef CONFIG_ARM_VIRT_EXT
mrs r0, spsr @ Get saved CPU boot mode
and r0, r0, #MODE_MASK
cmp r0, #HYP_MODE @ if not booted in HYP mode...
bne __enter_kernel @ boot kernel directly
adr r12, .L__hyp_reentry_vectors_offset
ldr r0, [r12]
add r0, r0, r12
bl __hyp_set_vectors
__HVC(0) @ otherwise bounce to hyp mode
b . @ should never be reached
.align 2
.L__hyp_reentry_vectors_offset: .long __hyp_reentry_vectors - .
#else
b __enter_kernel
#endif
.align 2
.type LC0, #object
LC0: .word LC0 @ r1
.word __bss_start @ r2
.word _end @ r3
.word _edata @ r6
.word input_data_end - 4 @ r10 (inflated size location)
.word _got_start @ r11
.word _got_end @ ip
.word .L_user_stack_end @ sp
.word _end - restart + 16384 + 1024*1024
.size LC0, . - LC0
#ifdef CONFIG_ARCH_RPC
.globl params
params: ldr r0, =0x10000100 @ params_phys for RPC
mov pc, lr
.ltorg
.align
#endif
/*
* Turn on the cache. We need to setup some page tables so that we
* can have both the I and D caches on.
*
* We place the page tables 16k down from the kernel execution address,
* and we hope that nothing else is using it. If we're using it, we
* will go pop!
*
* On entry,
* r4 = kernel execution address
* r7 = architecture number
* r8 = atags pointer
* On exit,
* r0, r1, r2, r3, r9, r10, r12 corrupted
* This routine must preserve:
* r4, r7, r8
*/
.align 5
cache_on: mov r3, #8 @ cache_on function
b call_cache_fn
/*
* Initialize the highest priority protection region, PR7
* to cover all 32bit address and cacheable and bufferable.
*/
__armv4_mpu_cache_on:
mov r0, #0x3f @ 4G, the whole
mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
mcr p15, 0, r0, c6, c7, 1
mov r0, #0x80 @ PR7
mcr p15, 0, r0, c2, c0, 0 @ D-cache on
mcr p15, 0, r0, c2, c0, 1 @ I-cache on
mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
mov r0, #0xc000
mcr p15, 0, r0, c5, c0, 1 @ I-access permission
mcr p15, 0, r0, c5, c0, 0 @ D-access permission
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
mrc p15, 0, r0, c1, c0, 0 @ read control reg
@ ...I .... ..D. WC.M
orr r0, r0, #0x002d @ .... .... ..1. 11.1
orr r0, r0, #0x1000 @ ...1 .... .... ....
mcr p15, 0, r0, c1, c0, 0 @ write control reg
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ flush(inval) I-Cache
mcr p15, 0, r0, c7, c6, 0 @ flush(inval) D-Cache
mov pc, lr
__armv3_mpu_cache_on:
mov r0, #0x3f @ 4G, the whole
mcr p15, 0, r0, c6, c7, 0 @ PR7 Area Setting
mov r0, #0x80 @ PR7
mcr p15, 0, r0, c2, c0, 0 @ cache on
mcr p15, 0, r0, c3, c0, 0 @ write-buffer on
mov r0, #0xc000
mcr p15, 0, r0, c5, c0, 0 @ access permission
mov r0, #0
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
/*
* ?? ARMv3 MMU does not allow reading the control register,
* does this really work on ARMv3 MPU?
*/
mrc p15, 0, r0, c1, c0, 0 @ read control reg
@ .... .... .... WC.M
orr r0, r0, #0x000d @ .... .... .... 11.1
/* ?? this overwrites the value constructed above? */
mov r0, #0
mcr p15, 0, r0, c1, c0, 0 @ write control reg
/* ?? invalidate for the second time? */
mcr p15, 0, r0, c7, c0, 0 @ invalidate whole cache v3
mov pc, lr
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
#define CB_BITS 0x08
#else
#define CB_BITS 0x0c
#endif
__setup_mmu: sub r3, r4, #16384 @ Page directory size
bic r3, r3, #0xff @ Align the pointer
bic r3, r3, #0x3f00
/*
* Initialise the page tables, turning on the cacheable and bufferable
* bits for the RAM area only.
*/
mov r0, r3
mov r9, r0, lsr #18
mov r9, r9, lsl #18 @ start of RAM
add r10, r9, #0x10000000 @ a reasonable RAM size
mov r1, #0x12 @ XN|U + section mapping
orr r1, r1, #3 << 10 @ AP=11
add r2, r3, #16384
1: cmp r1, r9 @ if virt > start of RAM
cmphs r10, r1 @ && end of RAM > virt
bic r1, r1, #0x1c @ clear XN|U + C + B
orrlo r1, r1, #0x10 @ Set XN|U for non-RAM
orrhs r1, r1, r6 @ set RAM section settings
str r1, [r0], #4 @ 1:1 mapping
add r1, r1, #1048576
teq r0, r2
bne 1b
/*
* If ever we are running from Flash, then we surely want the cache
* to be enabled also for our execution instance... We map 2MB of it
* so there is no map overlap problem for up to 1 MB compressed kernel.
* If the execution is in RAM then we would only be duplicating the above.
*/
orr r1, r6, #0x04 @ ensure B is set for this
orr r1, r1, #3 << 10
mov r2, pc
mov r2, r2, lsr #20
orr r1, r1, r2, lsl #20
add r0, r3, r2, lsl #2
str r1, [r0], #4
add r1, r1, #1048576
str r1, [r0]
mov pc, lr
ENDPROC(__setup_mmu)
@ Enable unaligned access on v6, to allow better code generation
@ for the decompressor C code:
__armv6_mmu_cache_on:
mrc p15, 0, r0, c1, c0, 0 @ read SCTLR
bic r0, r0, #2 @ A (no unaligned access fault)
orr r0, r0, #1 << 22 @ U (v6 unaligned access model)
mcr p15, 0, r0, c1, c0, 0 @ write SCTLR
b __armv4_mmu_cache_on
__arm926ejs_mmu_cache_on:
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mov r0, #4 @ put dcache in WT mode
mcr p15, 7, r0, c15, c0, 0
#endif
__armv4_mmu_cache_on:
mov r12, lr
#ifdef CONFIG_MMU
mov r6, #CB_BITS | 0x12 @ U
bl __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
mrc p15, 0, r0, c1, c0, 0 @ read control reg
orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
orr r0, r0, #0x0030
ARM_BE8( orr r0, r0, #1 << 25 ) @ big-endian page tables
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
#endif
mov pc, r12
__armv7_mmu_cache_on:
mov r12, lr
#ifdef CONFIG_MMU
mrc p15, 0, r11, c0, c1, 4 @ read ID_MMFR0
tst r11, #0xf @ VMSA
movne r6, #CB_BITS | 0x02 @ !XN
blne __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
tst r11, #0xf @ VMSA
mcrne p15, 0, r0, c8, c7, 0 @ flush I,D TLBs
#endif
mrc p15, 0, r0, c1, c0, 0 @ read control reg
bic r0, r0, #1 << 28 @ clear SCTLR.TRE
orr r0, r0, #0x5000 @ I-cache enable, RR cache replacement
orr r0, r0, #0x003c @ write buffer
bic r0, r0, #2 @ A (no unaligned access fault)
orr r0, r0, #1 << 22 @ U (v6 unaligned access model)
@ (needed for ARM1176)
#ifdef CONFIG_MMU
ARM_BE8( orr r0, r0, #1 << 25 ) @ big-endian page tables
mrcne p15, 0, r6, c2, c0, 2 @ read ttb control reg
orrne r0, r0, #1 @ MMU enabled
movne r1, #0xfffffffd @ domain 0 = client
bic r6, r6, #1 << 31 @ 32-bit translation system
bic r6, r6, #(7 << 0) | (1 << 4) @ use only ttbr0
mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer
mcrne p15, 0, r1, c3, c0, 0 @ load domain access control
mcrne p15, 0, r6, c2, c0, 2 @ load ttb control
#endif
mcr p15, 0, r0, c7, c5, 4 @ ISB
mcr p15, 0, r0, c1, c0, 0 @ load control register
mrc p15, 0, r0, c1, c0, 0 @ and read it back
mov r0, #0
mcr p15, 0, r0, c7, c5, 4 @ ISB
mov pc, r12
__fa526_cache_on:
mov r12, lr
mov r6, #CB_BITS | 0x12 @ U
bl __setup_mmu
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 @ Invalidate whole cache
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
mrc p15, 0, r0, c1, c0, 0 @ read control reg
orr r0, r0, #0x1000 @ I-cache enable
bl __common_mmu_cache_on
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ flush UTLB
mov pc, r12
__common_mmu_cache_on:
#ifndef CONFIG_THUMB2_KERNEL
#ifndef DEBUG
orr r0, r0, #0x000d @ Write buffer, mmu
#endif
mov r1, #-1
mcr p15, 0, r3, c2, c0, 0 @ load page table pointer
mcr p15, 0, r1, c3, c0, 0 @ load domain access control
b 1f
.align 5 @ cache line aligned
1: mcr p15, 0, r0, c1, c0, 0 @ load control register
mrc p15, 0, r0, c1, c0, 0 @ and read it back to
sub pc, lr, r0, lsr #32 @ properly flush pipeline
#endif
#define PROC_ENTRY_SIZE (4*5)
/*
* Here follow the relocatable cache support functions for the
* various processors. This is a generic hook for locating an
* entry and jumping to an instruction at the specified offset
* from the start of the block. Please note this is all position
* independent code.
*
* r1 = corrupted
* r2 = corrupted
* r3 = block offset
* r9 = corrupted
* r12 = corrupted
*/
call_cache_fn: adr r12, proc_types
#ifdef CONFIG_CPU_CP15
mrc p15, 0, r9, c0, c0 @ get processor ID
#elif defined(CONFIG_CPU_V7M)
/*
* On v7-M the processor id is located in the V7M_SCB_CPUID
* register, but as cache handling is IMPLEMENTATION DEFINED on
* v7-M (if existant at all) we just return early here.
* If V7M_SCB_CPUID were used the cpu ID functions (i.e.
* __armv7_mmu_cache_{on,off,flush}) would be selected which
* use cp15 registers that are not implemented on v7-M.
*/
bx lr
#else
ldr r9, =CONFIG_PROCESSOR_ID
#endif
1: ldr r1, [r12, #0] @ get value
ldr r2, [r12, #4] @ get mask
eor r1, r1, r9 @ (real ^ match)
tst r1, r2 @ & mask
ARM( addeq pc, r12, r3 ) @ call cache function
THUMB( addeq r12, r3 )
THUMB( moveq pc, r12 ) @ call cache function
add r12, r12, #PROC_ENTRY_SIZE
b 1b
/*
* Table for cache operations. This is basically:
* - CPU ID match
* - CPU ID mask
* - 'cache on' method instruction
* - 'cache off' method instruction
* - 'cache flush' method instruction
*
* We match an entry using: ((real_id ^ match) & mask) == 0
*
* Writethrough caches generally only need 'on' and 'off'
* methods. Writeback caches _must_ have the flush method
* defined.
*/
.align 2
.type proc_types,#object
proc_types:
.word 0x41000000 @ old ARM ID
.word 0xff00f000
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
.word 0x41007000 @ ARM7/710
.word 0xfff8fe00
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
.word 0x41807200 @ ARM720T (writethrough)
.word 0xffffff00
W(b) __armv4_mmu_cache_on
W(b) __armv4_mmu_cache_off
mov pc, lr
THUMB( nop )
.word 0x41007400 @ ARM74x
.word 0xff00ff00
W(b) __armv3_mpu_cache_on
W(b) __armv3_mpu_cache_off
W(b) __armv3_mpu_cache_flush
.word 0x41009400 @ ARM94x
.word 0xff00ff00
W(b) __armv4_mpu_cache_on
W(b) __armv4_mpu_cache_off
W(b) __armv4_mpu_cache_flush
.word 0x41069260 @ ARM926EJ-S (v5TEJ)
.word 0xff0ffff0
W(b) __arm926ejs_mmu_cache_on
W(b) __armv4_mmu_cache_off
W(b) __armv5tej_mmu_cache_flush
.word 0x00007000 @ ARM7 IDs
.word 0x0000f000
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
mov pc, lr
THUMB( nop )
@ Everything from here on will be the new ID system.