start.s.svn-base

u-boot for S3c2443 processor

/*
 * Copyright (C) 2003  Motorola,Inc.
 * Xianghua Xiao<[e-mail]>
 *
 * 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
 */

/* U-Boot Startup Code for Motorola 85xx PowerPC based Embedded Boards
 *
 * The processor starts at 0xfffffffc and the code is first executed in the
 * last 4K page(0xfffff000-0xffffffff) in flash/rom.
 *
 */

#include <config.h>
#include <mpc85xx.h>
#include <version.h>

#define _LINUX_CONFIG_H 1	/* avoid reading Linux autoconf.h file	*/

#include <ppc_asm.tmpl>
#include <ppc_defs.h>

#include <asm/cache.h>
#include <asm/mmu.h>

#ifndef	 CONFIG_IDENT_STRING
#define	 CONFIG_IDENT_STRING ""
#endif

#undef	MSR_KERNEL
#define MSR_KERNEL ( MSR_ME  )	/* Machine Check */

/*
 * Set up GOT: Global Offset Table
 *
 * Use r14 to access the GOT
 */
	START_GOT
	GOT_ENTRY(_GOT2_TABLE_)
	GOT_ENTRY(_FIXUP_TABLE_)

	GOT_ENTRY(_start)
	GOT_ENTRY(_start_of_vectors)
	GOT_ENTRY(_end_of_vectors)
	GOT_ENTRY(transfer_to_handler)

	GOT_ENTRY(__init_end)
	GOT_ENTRY(_end)
	GOT_ENTRY(__bss_start)
	END_GOT

/*
 * e500 Startup -- after reset only the last 4KB of the effective
 * address space is mapped in the MMU L2 TLB1 Entry0. The .bootpg
 * section is located at THIS LAST page and basically does three
 * things: clear some registers, set up exception tables and
 * add more TLB entries for 'larger spaces'(e.g. the boot rom) to
 * continue the boot procedure.

 * Once the boot rom is mapped by TLB entries we can proceed
 * with normal startup.
 *
 */

    .section .bootpg,"ax"
    .globl _start_e500

_start_e500:
#if defined(CONFIG_MPC85xx_REV1)
	li	r0,0x2000
	mtspr	977,r0
#endif

	/* Clear and set up some registers. Note: Some registers need strict
	 * synchronization by sync/mbar/msync/isync when being "mtspr".
	 * BookE: isync before PID,tlbivax,tlbwe
	 * BookE: isync after MSR,PID; msync_isync after tlbivax & tlbwe
	 * E500:  msync,isync before L1CSR0
	 * E500:  isync after BBEAR,BBTAR,BUCSR,DBCR0,DBCR1,HID0,HID1,L1CSR0
	 *        L1CSR1, MAS[0,1,2,3,4,6],MMUCSR0, PID[0,1,2],SPEFCSR
	 */

	/* invalidate d-cache */
	mfspr	r0,L1CSR0
	ori	r0,r0,0x0002
	msync
	isync
	mtspr	L1CSR0,r0
	isync

	/* disable d-cache */
	li	r0,0x0
	mtspr	L1CSR0,r0
	isync

	/* invalidate i-cache */
	mfspr	r0,L1CSR1
	ori	r0,r0,0x0002
	mtspr	L1CSR1,r0
	isync

	/* disable i-cache */
	li	r0,0x0
	mtspr	L1CSR1,r0
	isync

	/* clear registers */
	sync
	li	r0,0
	mtspr	SRR0,r0
	mtspr	SRR1,r0
	mtspr	CSRR0,r0
	mtspr	CSRR1,r0
	mtspr	MCSRR0,r0
	mtspr	MCSRR1,r0

	mtspr	ESR,r0
	mtspr	MCSR,r0
	mtspr	DEAR,r0

	mtspr	DBCR0,r0
	isync
	mtspr	DBCR1,r0
	isync
	mtspr	DBCR2,r0
	isync
	mtspr	IAC1,r0
	mtspr	IAC2,r0
	mtspr	DAC1,r0
	mtspr	DAC2,r0

	mfspr	r1,DBSR
	mtspr	DBSR,r1		/* Clear all valid bits */

	isync
	mtspr	PID0,r0
	isync
	mtspr	PID1,r0
	isync
	mtspr	PID2,r0
	isync

	mtspr	TCR,r0

	mtspr	BUCSR,r0	/* disable branch prediction */
	isync

	mtspr	HID0,r0
	isync
	mtspr	HID1,r0
	isync

	mtspr   MAS4,r0
	isync
	mtspr   MAS6,r0
	isync

	/* Setup interrupt vectors */
	mtspr IVPR, r0

	li      r1,0x0100
	mtspr	IVOR0,r1	/* 0: Critical input */
	li      r1,0x0200
	mtspr	IVOR1,r1	/* 1: Machine check */
	li      r1,0x0300
	mtspr	IVOR2,r1	/* 2: Data storage */
	li      r1,0x0400
	mtspr	IVOR3,r1	/* 3: Instruction storage */
	li	r1,0x0500
	mtspr	IVOR4,r1	/* 4: External interrupt */
	li	r1,0x0600
	mtspr	IVOR5,r1	/* 5: Alignment */
	li	r1,0x0700
	mtspr	IVOR6,r1	/* 6: Program check */
	li	r1,0x0800
	mtspr	IVOR7,r1	/* 7: floating point unavailable */
	li	r1,0x0c00
	mtspr	IVOR8,r1	/* 8: System call */
	/* 9: Auxiliary processor unavailable(unsupported) */
	li	r1,0x1000
	mtspr	IVOR10,r1	/* 10: Decrementer */
	li	r1,0x1400
	mtspr	IVOR13,r1	/* 13: Data TLB error */
	li	r1,0x1300
	mtspr	IVOR14,r1	/* 14: Instruction TLB error */
	li	r1,0x2000
	mtspr	IVOR15,r1	/* 15: Debug */

	/* invalidate MMU L1/L2 */
	/* Note: before invalidate MMU L1/L2, we read TLB1 Entry 0 and then
	 * write it back immediately to fixup a bug(Errata CPU4)  for this initial
	 * TLB1 entry 0,otherwise the TLB1 entry 0 will be invalidated.
	 */
#if defined(CONFIG_MPC85xx_REV1)
	lis	r2,0x1000
	mtspr	MAS0,r2
	tlbre
	tlbwe
	isync
	li      r2, 0x001e
	mtspr   MMUCSR0, r2
	isync
#endif

	/* After reset, CCSRBAR is located at CFG_CCSRBAR_DEFAULT, i.e.
	 * 0xff700000-0xff800000. We need add a TLB1 entry for this 1MB
	 * region before we can access any CCSR registers such as L2
	 * registers, Local Access Registers,etc. We will also re-allocate
	 * CFG_CCSRBAR_DEFAULT to CFG_CCSRBAR immediately after TLB1 setup.
	 *
	 * Please refer to board-specif directory for TLB1 entry configuration.
	 * (e.g. board/<yourboard>/init.S)
	 *
	 */
	bl 	tlb1_entry
	mr	r5,r0
	li	r1,0x000f	/* max 16 TLB1 entries */
	mtctr	r1
	lwzu	r4,0(r5)	/* how many TLB1 entries we actually use */

0:	cmpwi	r4,0
	beq	1f
	lwzu	r0,4(r5)
	lwzu	r1,4(r5)
	lwzu	r2,4(r5)
	lwzu	r3,4(r5)
	mtspr	MAS0,r0
	mtspr	MAS1,r1
	mtspr	MAS2,r2
	mtspr	MAS3,r3
	isync
	msync
	tlbwe
	isync
	addi	r4,r4,-1
	bdnz	0b

1:
#if (CFG_CCSRBAR_DEFAULT != CFG_CCSRBAR)
	/* Special sequence needed to update CCSRBAR itself */
	lis	r4, CFG_CCSRBAR_DEFAULT@h
	ori	r4, r4, CFG_CCSRBAR_DEFAULT@l

	lis   	r5, CFG_CCSRBAR@h
	ori   	r5, r5, CFG_CCSRBAR@l
	srwi	r6,r5,12
	stw	r6, 0(r4)
	isync

	lis	r5, 0xffff
	ori	r5,r5,0xf000
	lwz	r5, 0(r5)
	isync

	lis	r3, CFG_CCSRBAR@h
	lwz	r5, CFG_CCSRBAR@l(r3)
	isync
#endif

	/*  invalidate all TLB0 entries */
	li 	r3,4
	li	r4,0
	tlbivax	r4,r3
#if defined(CONFIG_MPC85xx_REV1) /* Errata CPU6 */
	nop
#endif

	/* set up local access windows, defined at board/<boardname>/init.S */
	lis	r7,CFG_CCSRBAR@h
	ori	r7,r7,CFG_CCSRBAR@l

	bl 	law_entry
	mr	r6,r0
#if  defined(CONFIG_RAM_AS_FLASH)
	li	r1,0x0006
#else
	li	r1,0x0007	/*we have 8 LAWs, but reseve one for boot-over-rio-or-pci */
#endif
	mtctr	r1
	lwzu	r5,0(r6)	/* how many windows we actually use */

#if defined(CONFIG_RAM_AS_FLASH)
	li 	r2,0x0c48
	li	r1,0x0c50
#else
	li	r2,0x0c28	/* the first pair is reserved for boot-over-rio-or-pci */
	li	r1,0x0c30
#endif

0:	cmpwi	r5,0
	beq	1f
	lwzu	r4,4(r6)
	lwzu	r3,4(r6)
	stwx	r4,r7,r2
	stwx	r3,r7,r1
	addi	r5,r5,-1
	addi	r2,r2,0x0020
	addi	r1,r1,0x0020
	bdnz	0b

	/* Jump out the last 4K page and continue to 'normal' start */
1:	bl	3f
	b	_start

3:	li	r0,0
	mtspr	SRR1,r0		/* Keep things disabled for now */
	mflr	r1
	mtspr	SRR0,r1
	rfi

/*
 * r3 - 1st arg to board_init(): IMMP pointer
 * r4 - 2nd arg to board_init(): boot flag
 */
	.text
	.long	0x27051956		/* U-BOOT Magic Number			*/
	.globl	version_string
version_string:
	.ascii U_BOOT_VERSION
	.ascii " (", __DATE__, " - ", __TIME__, ")"
	.ascii CONFIG_IDENT_STRING, "\0"

	. = EXC_OFF_SYS_RESET
	.globl	_start
_start:
	/* Clear and set up some registers. */
	li	r0,0x0000
	lis	r1,0xffff
	mtspr	DEC,r0			/* prevent dec exceptions */
	mttbl	r0			/* prevent fit & wdt exceptions */
	mttbu	r0
	mtspr	TSR,r1			/* clear all timer exception status */
	mtspr	TCR,r0			/* disable all */
	mtspr	ESR,r0			/* clear exception syndrome register */
	mtspr	MCSR,r0			/* machine check syndrome register */
	mtxer	r0			/* clear integer exception register */
	lis	r1,0x0002		/* set CE bit (Critical Exceptions) */
	ori	r1,r1,0x1200		/* set ME/DE bit */
	mtmsr	r1			/* change MSR */
	isync

	/* Enable Time Base and Select Time Base Clock */
	li	r0,0x4000		/* time base is processor clock */
	mtspr	HID0,r0
	isync

#if defined(CONFIG_ADDR_STREAMING)
	li	r0,0x3000
#else
	li	r0,0x1000
#endif
	mtspr	HID1,r0
	isync

	/* Enable Branch Prediction */
#if defined(CONFIG_BTB)
	li	r0,0x201		/* BBFI = 1, BPEN = 1 */
	mtspr	BUCSR,r0
	isync
#endif

#if defined(CFG_INIT_DBCR)
	lis	r1,0xffff
	ori	r1,r1,0xffff
	mtspr	dbsr,r1			/* Clear all status bits */
	lis	r0,CFG_INIT_DBCR@h	/* DBCR0[IDM] must be set */
	ori	r0,r0,CFG_INIT_DBCR@l
	mtspr	dbcr0,r0
	isync
#endif

/* L1 DCache is used for initial RAM */
	mfspr	r2, L1CSR0
	ori    	r2, r2, 0x0003
	oris   	r2, r2, 0x0001
	msync
	isync
	mtspr  	L1CSR0, r2	/* enable/invalidate L1 Dcache */
	isync

	/* Allocate Initial RAM in data cache.
	 */
	lis     r3, CFG_INIT_RAM_ADDR@h
	ori     r3, r3, CFG_INIT_RAM_ADDR@l
	li      r2, 512 /* 512*32=16K */
	mtctr   r2
	li	r0, 0
1:
	dcbz	r0, r3
	dcbtls  0,r0, r3
	addi    r3, r3, 32
	bdnz    1b

#ifndef CFG_RAMBOOT
	/* Calculate absolute address in FLASH and jump there           */
	/*--------------------------------------------------------------*/
	lis     r3, CFG_MONITOR_BASE@h
	ori     r3, r3, CFG_MONITOR_BASE@l
	addi    r3, r3, in_flash - _start + EXC_OFF_SYS_RESET
	mtlr    r3
	blr

in_flash:
#endif  /* CFG_RAMBOOT */

	/* Setup the stack in initial RAM,could be L2-as-SRAM or L1 dcache*/
	lis	r1,CFG_INIT_RAM_ADDR@h
	ori	r1,r1,CFG_INIT_SP_OFFSET@l

	li	r0,0
	stwu	r0,-4(r1)
	stwu	r0,-4(r1)		/* Terminate call chain */

	stwu	r1,-8(r1)		/* Save back chain and move SP */
	lis	r0,RESET_VECTOR@h	/* Address of reset vector */
	ori	r0,r0, RESET_VECTOR@l
	stwu	r1,-8(r1)		/* Save back chain and move SP */
	stw	r0,+12(r1)		/* Save return addr (underflow vect) */

	GET_GOT
	bl	cpu_init_f
	bl	icache_enable
	bl	board_init_f
	sync


/* --FIXME-- machine check with MCSRRn and rfmci */

	.globl	_start_of_vectors
_start_of_vectors:
#if 0
/* Critical input. */
	CRIT_EXCEPTION(0x0100, CritcalInput, CritcalInputException)
#endif
/* Machine check --FIXME-- Should be MACH_EXCEPTION */
	CRIT_EXCEPTION(0x0200, MachineCheck, MachineCheckException)

/* Data Storage exception. */
	STD_EXCEPTION(0x0300, DataStorage, UnknownException)

/* Instruction Storage exception. */
	STD_EXCEPTION(0x0400, InstStorage, UnknownException)

/* External Interrupt exception. */
	STD_EXCEPTION(0x0500, ExtInterrupt, UnknownException)

/* Alignment exception. */
	. = 0x0600
Alignment:
	EXCEPTION_PROLOG
	mfspr	r4,DAR
	stw	r4,_DAR(r21)
	mfspr	r5,DSISR
	stw	r5,_DSISR(r21)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	li	r20,MSR_KERNEL
	rlwimi	r20,r23,0,16,16		/* copy EE bit from saved MSR */
	lwz	r6,GOT(transfer_to_handler)
	mtlr	r6
	blrl
.L_Alignment:
	.long	AlignmentException - _start + EXC_OFF_SYS_RESET
	.long	int_return - _start + EXC_OFF_SYS_RESET

/* Program check exception */
	. = 0x0700
ProgramCheck:
	EXCEPTION_PROLOG
	addi	r3,r1,STACK_FRAME_OVERHEAD
	li	r20,MSR_KERNEL
	rlwimi	r20,r23,0,16,16		/* copy EE bit from saved MSR */
	lwz	r6,GOT(transfer_to_handler)
	mtlr	r6
	blrl
.L_ProgramCheck:
	.long	ProgramCheckException - _start + EXC_OFF_SYS_RESET
	.long	int_return - _start + EXC_OFF_SYS_RESET

	/* No FPU on MPC85xx.  This exception is not supposed to happen.
	*/
	STD_EXCEPTION(0x0800, FPUnavailable, UnknownException)
	STD_EXCEPTION(0x0900, Decrementer, timer_interrupt)
	STD_EXCEPTION(0x0a00, Trap_0a, UnknownException)
	STD_EXCEPTION(0x0b00, Trap_0b, UnknownException)

	. = 0x0c00
/*
 * r0 - SYSCALL number
 * r3-... arguments
 */
SystemCall:
	addis   r11,r0,0                /* get functions table addr */
	ori     r11,r11,0               /* Note: this code is patched in trap_init */
	addis   r12,r0,0                /* get number of functions */
	ori     r12,r12,0

	cmplw   0, r0, r12
	bge     1f

	rlwinm  r0,r0,2,0,31            /* fn_addr = fn_tbl[r0] */
	add     r11,r11,r0
	lwz     r11,0(r11)

	li      r20,0xd00-4             /* Get stack pointer */
	lwz     r12,0(r20)
	subi    r12,r12,12              /* Adjust stack pointer */
	li      r0,0xc00+_end_back-SystemCall
	cmplw   0, r0, r12              /* Check stack overflow */
	bgt     1f
	stw     r12,0(r20)

	mflr    r0
	stw     r0,0(r12)
	mfspr   r0,SRR0
	stw     r0,4(r12)
	mfspr   r0,SRR1
	stw     r0,8(r12)

	li      r12,0xc00+_back-SystemCall
	mtlr    r12
	mtspr   SRR0,r11

1:      SYNC
	rfi
_back:

	mfmsr   r11                     /* Disable interrupts */
	li      r12,0
	ori     r12,r12,MSR_EE
	andc    r11,r11,r12
	SYNC                            /* Some chip revs need this... */
	mtmsr   r11
	SYNC

	li      r12,0xd00-4             /* restore regs */
	lwz     r12,0(r12)

	lwz     r11,0(r12)
	mtlr    r11
	lwz     r11,4(r12)
	mtspr   SRR0,r11
	lwz     r11,8(r12)
	mtspr   SRR1,r11

	addi    r12,r12,12              /* Adjust stack pointer */
	li      r20,0xd00-4
	stw     r12,0(r20)

	SYNC
	rfi
_end_back:

	STD_EXCEPTION(0xd00, SingleStep, UnknownException)

	STD_EXCEPTION(0xe00, Trap_0e, UnknownException)
	STD_EXCEPTION(0xf00, Trap_0f, UnknownException)

	STD_EXCEPTION(0x1000, PIT, PITException)

	STD_EXCEPTION(0x1100, InstructionTLBMiss, UnknownException)
	STD_EXCEPTION(0x1200, DataTLBMiss, UnknownException)
	STD_EXCEPTION(0x1300, InstructionTLBError, UnknownException)
	STD_EXCEPTION(0x1400, DataTLBError, UnknownException)