S5PV210的uboot第一阶段start.S SD卡启动代码分析

/*
 *  armboot - Startup Code for S5PC110/ARM-Cortex CPU-core
 *
 *  Copyright (c) 2009	Samsung Electronics
 *
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 * Base codes by scsuh (sc.suh)
 */

#include 
#include 
#if defined(CONFIG_ENABLE_MMU)
#include 
#endif
#include 

#ifndef CONFIG_ENABLE_MMU
#ifndef CFG_PHY_UBOOT_BASE
#define CFG_PHY_UBOOT_BASE	CFG_UBOOT_BASE
#endif
#endif

/*
 *************************************************************************
 *
 * Jump vector table as in table 3.1 in [1]
 *
 *************************************************************************
 */
 /*占位使用,SD卡启动时,需要对前16kb进行校验,
 检验方式为所有数据加和(不包含前16字节)
 前16字节是uboot预留出来放置校验结果的区域,具体
 划分如下:
 0 - 3字节 存放bl1总的大小
 4 - 7字节 没有使用
 8- 11字节 存放校验和
 12-15字节 没有使用
 */

#if defined(CONFIG_EVT1) && !defined(CONFIG_FUSED)
	.word 0x2000
	.word 0x0
	.word 0x0
	.word 0x0
#endif
/*将_start设置为全局函数
*start函数入口先执行reset函数
*reset函数主要是禁止中断,设置CUP为svc32模式。
*执行完reset函数后设置中断向量表
*异常向量表:未定义指令异常、软中断异常、预处理指令异常、未使用、数据异常、 
*中断异常、快速中断异常;每条占一字节,地址范围为0x0000 0000~0x0000 0020 
*设置异常向量表的作用是识别bootloade
*只有设置完中断向量表后,CPU才可以正常进行中断处理
*/
.globl _start
_start: b	reset
	ldr	pc, _undefined_instruction
	ldr	pc, _software_interrupt
	ldr	pc, _prefetch_abort
	ldr	pc, _data_abort
	ldr	pc, _not_used
	ldr	pc, _irq
	ldr	pc, _fiq

/*
*使用.word伪指令分配一个word(4字节)
*将异常处理函数入口赋值给该内存
**/
_undefined_instruction:
	.word undefined_instruction
_software_interrupt:
	.word software_interrupt
_prefetch_abort:
	.word prefetch_abort
_data_abort:
	.word data_abort
_not_used:
	.word not_used
_irq:
	.word irq
_fiq:
	.word fiq
_pad:
	.word 0x12345678 /* now 16*4=64 */
/*
*异常向量表结束标志
*/
.global _end_vect
_end_vect:

/*
*接下来的代码采用16字节对齐,不足的地方使用0xdeadbeef填充
*/
	.balignl 16,0xdeadbeef
/*
 *************************************************************************
 *
 * Startup Code (reset vector)
 *
 * do important init only if we don't start from memory!
 * setup Memory and board specific bits prior to relocation.
 * relocate armboot to ram
 * setup stack
 *
 *************************************************************************
 */

/*
*代码段基地址在\board\samsung\x210\config.mk中定义
*/
_TEXT_BASE:
	.word	TEXT_BASE

/*
 * Below variable is very important because we use MMU in U-Boot.
 * Without it, we cannot run code correctly before MMU is ON.
 * by scsuh.
 */

/*
*启用MMU后uboot在ddr中的地址
*/
_TEXT_PHY_BASE:
	.word	CFG_PHY_UBOOT_BASE

/*
* *(_armboot_start) = _start
*/
.globl _armboot_start
_armboot_start:
	.word _start

/*
* These are defined in the board-specific linker script.
*/

/*
*设置栈头和栈尾,该符号定义在\uboot\board\samsung\x210\u-boot.lds中
*/ 
.globl _bss_start
_bss_start:
	.word __bss_start

.globl _bss_end
_bss_end:
	.word _end

/*
*中断的堆栈设置,在cpu_init中用到 
*/
#if defined(CONFIG_USE_IRQ)
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
	.word	0x0badc0de

/* IRQ stack memory (calculated at run-time) */
.globl FIQ_STACK_START
FIQ_STACK_START:
	.word 0x0badc0de
#endif

/*
 * the actual reset code
 */

/*
*ARM上电后首先执行的就是这段程序,
*置cpu到svc32模式,关闭中断;msr将0xd3写到cpsr_c
*/
reset:
	/*
	 * set the cpu to SVC32 mode and IRQ & FIQ disable
	 */
	@;mrs	r0,cpsr
	@;bic	r0,r0,#0x1f
	@;orr	r0,r0,#0xd3
	@;msr	cpsr,r0
	msr	cpsr_c, #0xd3		@ I & F disable, Mode: 0x13 - SVC


/*
 *************************************************************************
 *
 * CPU_init_critical registers
 *
 * setup important registers
 * setup memory timing
 *
 *************************************************************************
 */
         /*
         * we do sys-critical inits only at reboot,
         * not when booting from ram!
         */
/*
*cpu初始化
*/ 
cpu_init_crit:

#ifndef CONFIG_EVT1
#if 0	
	bl	v7_flush_dcache_all
#else
	bl	disable_l2cache

	mov	r0, #0x0	@ 
	mov	r1, #0x0	@ i	
	mov	r3, #0x0
	mov	r4, #0x0
lp1:
	mov	r2, #0x0	@ j
lp2:	
	mov	r3, r1, LSL #29		@ r3 = r1(i) <<29
	mov	r4, r2, LSL #6		@ r4 = r2(j) <<6
	orr	r4, r4, #0x2		@ r3 = (i<<29)|(j<<6)|(1<<1)
	orr	r3, r3, r4
	mov	r0, r3			@ r0 = r3
	bl	CoInvalidateDCacheIndex
	add	r2, #0x1		@ r2(j)++
	cmp	r2, #1024		@ r2 < 1024
	bne	lp2			@ jump to lp2
	add	r1, #0x1		@ r1(i)++
	cmp	r1, #8			@ r1(i) < 8
	bne	lp1			@ jump to lp1

	bl	set_l2cache_auxctrl
	
	bl	enable_l2cache
#endif
#endif
/*
*关闭d-cache和i-cache
*/	
	bl	disable_l2cache
/*
*初始化d/i-cache
*/
	bl	set_l2cache_auxctrl_cycle
/*
*使能d/i-cache
*/
	bl	enable_l2cache
	
       /*
        * Invalidate L1 I/D
        */
        /*
        *关闭TLB缓冲页表(mmu虚拟地址转物理地址的表)
        *关闭i-cache
        */
        mov	r0, #0                  @ set up for MCR
        mcr	p15, 0, r0, c8, c7, 0   @ invalidate TLBs
        mcr	p15, 0, r0, c7, c5, 0   @ invalidate icache

       /*
        * disable MMU stuff and caches 关闭MMU
        */
        mrc	p15, 0, r0, c1, c0, 0
        bic	r0, r0, #0x00002000     @ clear bits 13 (--V-)
        bic	r0, r0, #0x00000007     @ clear bits 2:0 (-CAM)
        orr	r0, r0, #0x00000002     @ set bit 1 (--A-) Align
        orr	r0, r0, #0x00000800     @ set bit 12 (Z---) BTB
        mcr 	p15, 0, r0, c1, c0, 0


        /* Read booting information 读取启动方式 sd?inand?norflash?sub?串口?*/
        ldr	r0, =PRO_ID_BASE
        ldr	r1, [r0,#OMR_OFFSET]
        bic	r2, r1, #0xffffffc1
/*
**电源管理,保持供电
*/
#ifdef CONFIG_VOGUES
	/* PS_HOLD(GPH0_0) set to output high */
	ldr	r0, =ELFIN_GPIO_BASE
	ldr	r1, =0x00000001
	str	r1, [r0, #GPH0CON_OFFSET]

	ldr	r1, =0x5500
	str	r1, [r0, #GPH0PUD_OFFSET]

	ldr	r1, =0x01
	str	r1, [r0, #GPH0DAT_OFFSET]
#endif

	/* NAND BOOT */
	cmp	r2, #0x0		@ 512B 4-cycle
	moveq	r3, #BOOT_NAND

	cmp	r2, #0x2		@ 2KB 5-cycle
	moveq	r3, #BOOT_NAND

	cmp	r2, #0x4		@ 4KB 5-cycle	8-bit ECC
	moveq	r3, #BOOT_NAND

	cmp	r2, #0x6		@ 4KB 5-cycle	16-bit ECC
	moveq	r3, #BOOT_NAND

	cmp	r2, #0x8		@ OneNAND Mux
	moveq	r3, #BOOT_ONENAND
/*
*本案例中使用的是SD卡启动所以这段代码会被执行
*/
	/* SD/MMC BOOT */
	cmp     r2, #0xc
	moveq   r3, #BOOT_MMCSD	

	/* NOR BOOT */
	cmp     r2, #0x14
	moveq   r3, #BOOT_NOR	

#if 0	/* Android C110 BSP uses OneNAND booting! */
	/* For second device booting */
	/* OneNAND BOOTONG failed */
	cmp     r2, #0x8
	moveq   r3, #BOOT_SEC_DEV
#endif
/*
*uart启动
*/
	/* Uart BOOTONG failed */
	cmp     r2, #(0x1<<4)
	moveq   r3, #BOOT_SEC_DEV
	
	ldr	r0, =INF_REG_BASE
	str	r3, [r0, #INF_REG3_OFFSET]     

	/*
	 * Go setup Memory and board specific bits prior to relocation.
	 */
/*
*初始化栈(用于函数调用)
*/
	ldr	sp, =0xd0036000 /* end of sram dedicated to u-boot */
	sub	sp, sp, #12	/* set stack */
	mov	fp, #0
/*
*调用lowlevel_init进行基础初始化
*lowlevel_init主要进行以下工作:
*检查复位状态,如果是唤醒就意味着有些初始化不能执行
*如果是唤醒,则需要进行IO状态恢复
*外部sram srom 初始化
*设置供电锁存
*初始化时钟,初始化DDR
*初始化串口,串口初始化成功后后打印o
*执行其他初始化后打印K(lowlevel_init执行没有问题串口就会打印OK)
*/	
	bl	lowlevel_init	/* go setup pll,mux,memory */
	/* To hold max8698 output before releasing power on switch,
	 * set PS_HOLD signal to high
	 */
/*
*再次供电锁存
*/
	ldr	r0, =0xE010E81C  /* PS_HOLD_CONTROL register */
	ldr	r1, =0x00005301	 /* PS_HOLD output high	*/
	str	r1, [r0]
/*
*再次设置栈(这次的栈设置在DDR中)
*/
	/* get ready to call C functions */
	ldr	sp, _TEXT_PHY_BASE	/* setup temp stack pointer */
	sub	sp, sp, #12
	mov	fp, #0			/* no previous frame, so fp=0 */

	/* when we already run in ram, we don't need to relocate U-Boot.
	 * and actually, memory controller must be configured before U-Boot
	 * is running in ram.
	 */
/*
*再次判断程序在哪里运行,决定是否执行Uboot代码重定位
*/
	ldr	r0, =0xff000fff
	bic	r1, pc, r0		/* r0 <- current base addr of code */
	ldr	r2, _TEXT_BASE		/* r1 <- original base addr in ram */
	bic	r2, r2, r0		/* r0 <- current base addr of code */
	cmp     r1, r2                  /* compare r0, r1                  */
/*
*如果代码本身就在DDR中则跳过代码拷贝
*
*/
	beq     after_copy		/* r0 == r1 then skip flash copy   */
	
/*
*判断在什么地方启动的(为了确定去哪里拷贝代码)
*实际运行时这段代码是成立的,所以mmcsd_boot会被执行
*mmcsd_boot实际调用了movi_bl2_copy函数进行拷贝
*movi_bl2_copy这个函数调用了一个三星固化好的函数
*copy_bl2(2, MOVI_BL2_POS, MOVI_BL2_BLKCNT,CFG_PHY_UBOOT_BASE, 0);
*分析参数:2表示通道2;MOVI_BL2_POS是uboot的第二部分在SD卡中的开始扇区,
*这个扇区数字必须和烧录uboot时烧录的位置相同;MOVI_BL2_BLKCNT是uboot的
*长度占用的扇区数;CFG_PHY_UBOOT_BASE是重定位时将uboot的第二部分复制到
*DDR中的起始地址(33E00000).
*/
#if defined(CONFIG_EVT1)
	/* If BL1 was copied from SD/MMC CH2 */
	ldr	r0, =0xD0037488
	ldr	r1, [r0]
	ldr	r2, =0xEB200000
	cmp	r1, r2
	beq     mmcsd_boot
#endif

	ldr	r0, =INF_REG_BASE
	ldr	r1, [r0, #INF_REG3_OFFSET]
	cmp	r1, #BOOT_NAND		/* 0x0 => boot device is nand */
	beq	nand_boot
	cmp	r1, #BOOT_ONENAND	/* 0x1 => boot device is onenand */
	beq	onenand_boot
	cmp     r1, #BOOT_MMCSD
	beq     mmcsd_boot
	cmp     r1, #BOOT_NOR
	beq     nor_boot
	cmp     r1, #BOOT_SEC_DEV
	beq     mmcsd_boot

nand_boot:
	mov	r0, #0x1000
	bl	copy_from_nand
	b	after_copy

onenand_boot:
	bl	onenand_bl2_copy
	b	after_copy

mmcsd_boot:
#if DELETE
	ldr     sp, _TEXT_PHY_BASE      
	sub     sp, sp, #12
	mov     fp, #0
#endif
	bl      movi_bl2_copy
	b       after_copy

nor_boot:
	bl      read_hword
	b       after_copy


after_copy:
/*
*初始化MMU,设置转换表,设置TTB转换表基地址,
*设置到P15的c2寄存器中(实际就是将c0000000开始的256MB映射到DMC0的30000000开始的物理内存中)
*/
#if defined(CONFIG_ENABLE_MMU)
enable_mmu:
	/* enable domain access */
	ldr	r5, =0x0000ffff
	mcr	p15, 0, r5, c3, c0, 0		@load domain access register

	/* Set the TTB register */
	ldr	r0, _mmu_table_base
	ldr	r1, =CFG_PHY_UBOOT_BASE
	ldr	r2, =0xfff00000
	bic	r0, r0, r2
	orr	r1, r0, r1
	mcr	p15, 0, r1, c2, c0, 0

	/* Enable the MMU */
mmu_on:
	mrc	p15, 0, r0, c1, c0, 0
	orr	r0, r0, #1
	mcr	p15, 0, r0, c1, c0, 0
	nop
	nop
	nop
	nop
#endif

/*
*再次设置栈(为uboot第二段c语言环境做准备)
*/
skip_hw_init:
	/* Set up the stack						    */
stack_setup:
#if defined(CONFIG_MEMORY_UPPER_CODE)
	ldr	sp, =(CFG_UBOOT_BASE + CFG_UBOOT_SIZE - 0x1000)
#else
	ldr	r0, _TEXT_BASE		/* upper 128 KiB: relocated uboot   */
	sub	r0, r0, #CFG_MALLOC_LEN	/* malloc area                      */
	sub	r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo                        */
#if defined(CONFIG_USE_IRQ)
	sub	r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
#endif
	sub	sp, r0, #12		/* leave 3 words for abort-stack    */

#endif
/*
*清除bss段
*/
clear_bss:
	ldr	r0, _bss_start		/* find start of bss segment        */
	ldr	r1, _bss_end		/* stop here                        */
	mov 	r2, #0x00000000		/* clear                            */

clbss_l:
	str	r2, [r0]		/* clear loop...                    */
	add	r0, r0, #4
	cmp	r0, r1
	ble	clbss_l
/*
*执行start_armboot函数(进入uboot的第二阶段)
*/	
	ldr	pc, _start_armboot

_start_armboot:
	.word start_armboot

#if defined(CONFIG_ENABLE_MMU)
_mmu_table_base:
	.word mmu_table
#endif

/*
 * copy U-Boot to SDRAM and jump to ram (from NAND or OneNAND)
 * r0: size to be compared
 * Load 1'st 2blocks to RAM because U-boot's size is larger than 1block(128k) size
 */
	.globl copy_from_nand
copy_from_nand:
	push	{lr}		/* save return address */

	mov	r9, r0
	
	mov	r9, #0x100		/* Compare about 8KB */
	bl	copy_uboot_to_ram
	tst 	r0, #0x0
	bne	copy_failed

#if defined(CONFIG_EVT1)
	ldr	r0, =0xd0020000
#else	
	ldr	r0, =0xd0030000
#endif
	ldr	r1, _TEXT_PHY_BASE	/* 0x23e00000 */

#if !defined(CONFIG_SECURE_BOOT)
1:	ldr	r3, [r0], #4
	ldr	r4, [r1], #4
	teq	r3, r4
	bne	compare_failed	/* not matched */
	subs	r9, r9, #4
	bne	1b
#endif
	pop	{pc}		/* all is OK */

copy_failed:
	nop			/* copy from nand failed */
	b	copy_failed

compare_failed:
	nop			/* compare failed */
	b	compare_failed

/*
 * we assume that cache operation is done before. (eg. cleanup_before_linux())
 * actually, we don't need to do anything about cache if not use d-cache in U-Boot
 * So, in this function we clean only MMU. by scsuh
 *
 * void	theLastJump(void *kernel, int arch_num, uint boot_params);
 */
#if defined(CONFIG_ENABLE_MMU)
	.globl theLastJump
theLastJump:
	mov	r9, r0
	ldr	r3, =0xfff00000
	ldr	r4, _TEXT_PHY_BASE
	adr	r5, phy_last_jump
	bic	r5, r5, r3
	orr	r5, r5, r4
	mov	pc, r5
phy_last_jump:
	/*
	 * disable MMU stuff
	 */
	mrc	p15, 0, r0, c1, c0, 0
	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
	mcr	p15, 0, r0, c1, c0, 0

	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */

	mov	r0, #0
	mov	pc, r9
#endif
/*
 *************************************************************************
 *
 * Interrupt handling
 *
 *************************************************************************
 */
@
@ IRQ stack frame.
@
#define S_FRAME_SIZE	72

#define S_OLD_R0	68
#define S_PSR		64
#define S_PC		60
#define S_LR		56
#define S_SP		52

#define S_IP		48
#define S_FP		44
#define S_R10		40
#define S_R9		36
#define S_R8		32
#define S_R7		28
#define S_R6		24
#define S_R5		20
#define S_R4		16
#define S_R3		12
#define S_R2		8
#define S_R1		4
#define S_R0		0

#define MODE_SVC 0x13
#define I_BIT	 0x80

/*
 * use bad_save_user_regs for abort/prefetch/undef/swi ...
 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
 */

	.macro	bad_save_user_regs
	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12

	ldr	r2, _armboot_start
	sub	r2, r2, #(CFG_MALLOC_LEN)
	sub	r2, r2, #(CFG_GBL_DATA_SIZE+8)	@ set base 2 words into abort stack
	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack

	add	r5, sp, #S_SP
	mov	r1, lr
	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
	mov	r0, sp				@ save current stack into r0 (param register)
	.endm

	.macro	irq_save_user_regs
	sub	sp, sp, #S_FRAME_SIZE
	stmia	sp, {r0 - r12}			@ Calling r0-r12
	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
	stmdb	r8, {sp, lr}^			@ Calling SP, LR
	str	lr, [r8, #0]			@ Save calling PC
	mrs	r6, spsr
	str	r6, [r8, #4]			@ Save CPSR
	str	r0, [r8, #8]			@ Save OLD_R0
	mov	r0, sp
	.endm

	.macro	irq_restore_user_regs
	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
	mov	r0, r0
	ldr	lr, [sp, #S_PC]			@ Get PC
	add	sp, sp, #S_FRAME_SIZE
	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
	.endm

	.macro get_bad_stack
	ldr	r13, _armboot_start		@ setup our mode stack (enter in banked mode)
	sub	r13, r13, #(CFG_MALLOC_LEN)	@ move past malloc pool
	sub	r13, r13, #(CFG_GBL_DATA_SIZE+8) @ move to reserved a couple spots for abort stack

	str	lr, [r13]			@ save caller lr in position 0 of saved stack
	mrs	lr, spsr			@ get the spsr
	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack

	mov	r13, #MODE_SVC			@ prepare SVC-Mode
	@ msr	spsr_c, r13
	msr	spsr, r13			@ switch modes, make sure moves will execute
	mov	lr, pc				@ capture return pc
	movs	pc, lr				@ jump to next instruction & switch modes.
	.endm

	.macro get_bad_stack_swi
	sub	r13, r13, #4			@ space on current stack for scratch reg.
	str	r0, [r13]			@ save R0's value.
	ldr	r0, _armboot_start		@ get data regions start
	sub	r0, r0, #(CFG_MALLOC_LEN)	@ move past malloc pool
	sub	r0, r0, #(CFG_GBL_DATA_SIZE+8)	@ move past gbl and a couple spots for abort stack
	str	lr, [r0]			@ save caller lr in position 0 of saved stack
	mrs	r0, spsr			@ get the spsr
	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
	ldr	r0, [r13]			@ restore r0
	add	r13, r13, #4			@ pop stack entry
	.endm

	.macro get_irq_stack			@ setup IRQ stack
	ldr	sp, IRQ_STACK_START
	.endm

	.macro get_fiq_stack			@ setup FIQ stack
	ldr	sp, FIQ_STACK_START
	.endm

/*
 * exception handlers
 */
	.align	5
undefined_instruction:
	get_bad_stack
	bad_save_user_regs
	bl	do_undefined_instruction

	.align	5
software_interrupt:
	get_bad_stack_swi
	bad_save_user_regs
	bl	do_software_interrupt

	.align	5
prefetch_abort:
	get_bad_stack
	bad_save_user_regs
	bl	do_prefetch_abort

	.align	5
data_abort:
	get_bad_stack
	bad_save_user_regs
	bl	do_data_abort

	.align	5
not_used:
	get_bad_stack
	bad_save_user_regs
	bl	do_not_used

#if defined(CONFIG_USE_IRQ)

	.align	5
irq:
	get_irq_stack
	irq_save_user_regs
	bl	do_irq
	irq_restore_user_regs

	.align	5
fiq:
	get_fiq_stack
	/* someone ought to write a more effiction fiq_save_user_regs */
	irq_save_user_regs
	bl	do_fiq
	irq_restore_user_regs

#else

	.align	5
irq:
	get_bad_stack
	bad_save_user_regs
	bl	do_irq

	.align	5
fiq:
	get_bad_stack
	bad_save_user_regs
	bl	do_fiq

#endif
	.align 5
.global arm_cache_flush
arm_cache_flush:
       mcr     p15, 0, r1, c7, c5, 0           @ invalidate I cache
       mov     pc, lr                          @ back to caller

/*
 *     v7_flush_dcache_all()
 *
 *     Flush the whole D-cache.
 *
 *     Corrupted registers: r0-r5, r7, r9-r11
 *
 *     - mm    - mm_struct describing address space
 */
       .align 5
.global v7_flush_dcache_all
v7_flush_dcache_all:

	ldr	r0, =0xffffffff
	mrc	p15, 1, r0, c0, c0, 1 		@ Read CLIDR
	ands	r3, r0, #0x7000000
	mov	r3, r3, LSR #23       		@ Cache level value (naturally aligned)
	beq 	Finished
	mov	r10, #0
Loop1:         
	add	r2, r10, r10, LSR #1  		@ Work out 3xcachelevel
	mov	r1, r0, LSR r2        		@ bottom 3 bits are the Ctype for this level
	and	r1, r1, #7            		@ get those 3 bits alone
	cmp	r1, #2
	blt	Skip                   		@ no cache or only instruction cache at this level
	mcr	p15, 2, r10, c0, c0, 0 		@ write the Cache Size selection register
	mov	r1, #0
	mcr	p15, 0, r1, c7, c5, 4 		@ PrefetchFlush to sync the change to the CacheSizeID reg
	mrc	p15, 1, r1, c0, c0, 0 		@ reads current Cache Size ID register
	and	r2, r1, #0x7           		@ extract the line length field
	add	r2, r2, #4            		@ add 4 for the line length offset (log2 16 bytes)
	ldr	r4, =0x3FF
	ands	r4, r4, r1, LSR #3   		@ R4 is the max number on the way size (right aligned)
	clz	r5, r4                		@ R5 is the bit position of the way size increment
	ldr	r7, =0x00007FFF
	ands	r7, r7, r1, LSR #13  		@ R7 is the max number of the index size (right aligned)
Loop2:         
	mov	r9, r4                      	@ R9 working copy of the max way size (right aligned)
Loop3:         
	orr	r11, r10, r9, LSL r5        	@ factor in the way number and cache number into R11
	orr	r11, r11, r7, LSL r2        	@ factor in the index number
	mcr	p15, 0, r11, c7, c6, 2 		@ invalidate by set/way
	subs	r9, r9, #1                 	@ decrement the way number
	bge	Loop3
	subs	r7, r7, #1                 	@ decrement the index
	bge	Loop2
Skip:          
	add	r10, r10, #2                	@ increment the cache number
	cmp	r3, r10
	bgt	Loop1
Finished:
	mov	pc, lr
	
       .align  5
.global disable_l2cache
disable_l2cache:
	mrc     p15, 0, r0, c1, c0, 1
	bic     r0, r0, #(1<<1)
	mcr     p15, 0, r0, c1, c0, 1
	mov	pc, lr


       .align  5
.global enable_l2cache
enable_l2cache:
	mrc     p15, 0, r0, c1, c0, 1
	orr     r0, r0, #(1<<1)
	mcr     p15, 0, r0, c1, c0, 1
	mov     pc, lr

       .align  5
.global set_l2cache_auxctrl
set_l2cache_auxctrl:
	mov	r0, #0x0
	mcr     p15, 1, r0, c9, c0, 2
	mov     pc, lr

       .align  5
.global set_l2cache_auxctrl_cycle
set_l2cache_auxctrl_cycle:
	mrc 	p15, 1, r0, c9, c0, 2
	bic 	r0, r0, #(0x1<<29)
	bic 	r0, r0, #(0x1<<21)
	bic 	r0, r0, #(0x7<<6)
	bic 	r0, r0, #(0x7<<0)
	mcr 	p15, 1, r0, c9, c0, 2
	mov     pc,lr

	.align 5
CoInvalidateDCacheIndex:
	;/* r0 = index */
	mcr     p15, 0, r0, c7, c6, 2
	mov     pc,lr


#if defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_CINTEGRATOR)
/* Use the IntegratorCP function from board/integratorcp/platform.S */
#elif defined(CONFIG_S5PC11X)
/* For future usage of S3C64XX*/
#else
	.align	5
.globl reset_cpu
reset_cpu:
	ldr	r1, rstctl	/* get addr for global reset reg */
	mov	r3, #0x2	/* full reset pll+mpu */
	str	r3, [r1]	/* force reset */
	mov	r0, r0
_loop_forever:
	b	_loop_forever
rstctl:
	.word	PM_RSTCTRL_WKUP

#endif

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