Patch by Kyle Harris, 20 May 2003:LABEL_2003_05_23_1450

In preparation for an ixp port, rename cpu/xscale and arch-xscale
into cpu/pxa and arch-pxa.

1 files changed, 474 insertions, 0 deletions

diff --git a/cpu/pxa/start.S b/cpu/pxa/start.S
new file mode 100644
index 0000000000..95b30e44e9
--- /dev/null
+++ b/cpu/pxa/start.S
@@ -0,0 +1,474 @@
+/*
+ *  armboot - Startup Code for XScale
+ *
+ *  Copyright (C) 1998	Dan Malek <dmalek@jlc.net>
+ *  Copyright (C) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
+ *  Copyright (C) 2000	Wolfgang Denk <wd@denx.de>
+ *  Copyright (C) 2001	Alex Züpke <azu@sysgo.de>
+ *  Copyright (C) 2002	Kyle Harris <kharris@nexus-tech.net>
+ *  Copyright (C) 2003  Robert Schwebel <r.schwebel@pengutronix.de>
+ *  Copyright (C) 2003  Kai-Uwe Bloehm <kai-uwe.bloem@auerswald.de>
+ *
+ * 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
+ */
+
+#include <config.h>
+#include <version.h>
+
+.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
+
+_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
+
+	.balignl 16,0xdeadbeef
+
+
+/*
+ * Startup Code (reset vector)
+ *
+ * do important init only if we don't start from memory!
+ * - relocate armboot to ram
+ * - setup stack
+ * - jump to second stage
+ */
+
+/*
+ * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
+ */
+_TEXT_BASE:
+	.word	TEXT_BASE
+
+.globl _armboot_start
+_armboot_start:
+	.word _start
+
+/*
+ * Note: _armboot_end_data and _armboot_end are defined
+ * by the (board-dependent) linker script.
+ * _armboot_end_data is the first usable FLASH address after armboot
+ */
+.globl _armboot_end_data
+_armboot_end_data:
+	.word armboot_end_data
+.globl _armboot_end
+_armboot_end:
+	.word armboot_end
+
+/*
+ * This is defined in the board specific linker script
+ */
+.globl _bss_start	
+_bss_start:	
+	.word bss_start
+
+.globl _bss_end
+_bss_end:
+	.word bss_end
+
+/*
+ * _armboot_real_end is the first usable RAM address behind armboot
+ * and the various stacks
+ */
+.globl _armboot_real_end
+_armboot_real_end:
+	.word 0x0badc0de
+
+/*
+ * We relocate uboot to this address (end of RAM - 128 KiB)
+ */
+.globl _uboot_reloc
+_uboot_reloc:
+	.word TEXT_BASE
+
+#ifdef 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						    */
+/*									    */
+/****************************************************************************/
+
+reset:
+	mrs	r0,cpsr			/* set the cpu to SVC32 mode	    */
+	bic	r0,r0,#0x1f		/* (superviser mode, M=10011)	    */
+	orr	r0,r0,#0x13
+	msr	cpsr,r0
+
+	bl	cpu_init_crit		/* we do sys-critical inits	    */
+
+relocate:				/* relocate U-Boot to RAM	    */
+	adr	r0, _start		/* r0 <- current position of code   */
+	ldr	r1, _TEXT_BASE		/* test if we run from flash or RAM */	
+	cmp     r0, r1                  /* don't reloc during debug         */
+	beq     stack_setup
+
+	ldr	r2, _armboot_start
+	ldr	r3, _armboot_end
+	sub	r2, r3, r2		/* r2 <- size of armboot            */
+	add	r2, r0, r2		/* r2 <- source end address         */
+
+copy_loop:
+	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
+	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
+	cmp	r0, r2			/* until source end addreee [r2]    */
+	ble	copy_loop
+
+	/* Set up the stack						    */
+
+stack_setup:
+
+	ldr	r0, _uboot_reloc	/* upper 128 KiB: relocated uboot   */
+	sub	r0, r0, #CFG_MALLOC_LEN /* malloc area			    */
+					/* FIXME: bdinfo should be here	    */
+	sub	sp, r0, #12		/* leave 3 words for abort-stack    */
+
+clear_bss:
+
+	ldr	r0, _bss_start		/* find start of bss segment        */
+	add	r0, r0, #4		/* start at first byte of bss       */
+	ldr	r1, _bss_end		/* stop here                        */
+	mov 	r2, #0x00000000		/* clear                            */
+
+clbss_l:str	r2, [r0]		/* clear loop...                    */
+	add	r0, r0, #4
+	cmp	r0, r1
+	bne	clbss_l	 
+
+
+	ldr	pc, _start_armboot
+
+_start_armboot: .word start_armboot
+
+
+/****************************************************************************/
+/*									    */
+/* CPU_init_critical registers						    */
+/*									    */
+/* - setup important registers						    */
+/* - setup memory timing						    */
+/*									    */
+/****************************************************************************/
+
+/* Interrupt-Controller base address				            */
+IC_BASE:	   .word	   0x40d00000
+#define ICMR	0x04
+
+/* Reset-Controller */
+RST_BASE:	.word	0x40f00030
+#define RCSR	0x00
+
+/* Operating System Timer */
+OSTIMER_BASE:	.word	0x40a00000
+#define OSMR3	0x0C
+#define OSCR	0x10
+#define OWER	0x18
+#define OIER	0x1C
+
+/* Clock Manager Registers					            */
+CC_BASE:	.word	0x41300000
+#define CCCR	0x00
+cpuspeed:	.word	CFG_CPUSPEED
+
+
+	/* RS: ???							    */
+	.macro CPWAIT
+	mrc  p15,0,r0,c2,c0,0
+	mov  r0,r0
+	sub  pc,pc,#4
+	.endm
+
+
+cpu_init_crit:
+
+	/* mask all IRQs						    */
+	ldr	r0, IC_BASE
+	mov	r1, #0x00
+	str	r1, [r0, #ICMR]
+
+#if defined(CFG_CPUSPEED)
+
+	/* set clock speed */
+	ldr	r0, CC_BASE
+	ldr	r1, cpuspeed
+	str	r1, [r0, #CCCR]
+	mov	r0, #2
+	mcr	p14, 0, r0, c6, c0, 0
+
+setspeed_done:
+#endif
+
+	/*
+	 * before relocating, we have to setup RAM timing
+	 * because memory timing is board-dependend, you will
+	 * find a memsetup.S in your board directory.
+	 */
+	mov	ip,	lr
+	bl	memsetup
+	mov	lr,	ip
+
+	/* Memory interfaces are working. Disable MMU and enable I-cache.   */
+
+	ldr	r0, =0x2001		/* enable access to all coproc.	    */
+	mcr	p15, 0, r0, c15, c1, 0
+	CPWAIT
+
+	mcr	p15, 0, r0, c7, c10, 4	/* drain the write & fill buffers   */
+	CPWAIT
+
+	mcr	p15, 0, r0, c7, c7, 0	/* flush Icache, Dcache and BTB	    */
+	CPWAIT
+
+	mcr	p15, 0, r0, c8, c7, 0	/* flush instuction and data TLBs   */
+	CPWAIT
+
+	/* Enable the Icache						    */
+/*
+	mrc	p15, 0, r0, c1, c0, 0
+	orr	r0, r0, #0x1800
+	mcr	p15, 0, r0, c1, c0, 0
+	CPWAIT
+*/
+	mov	pc, lr
+
+
+/****************************************************************************/
+/*									    */
+/* 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
+
+	/* use bad_save_user_regs for abort/prefetch/undef/swi ...	    */
+
+	.macro	bad_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}			/* Calling r0-r12	    */
+	add	r8, sp, #S_PC
+
+	ldr	r2, _armboot_end
+	add	r2, r2, #CONFIG_STACKSIZE
+	sub	r2, r2, #8
+	ldmia	r2, {r2 - r4}			/* get pc, cpsr, old_r0	    */
+	add	r0, sp, #S_FRAME_SIZE		/* restore sp_SVC	    */
+
+	add	r5, sp, #S_SP
+	mov	r1, lr
+	stmia	r5, {r0 - r4}			/* save sp_SVC, lr_SVC, pc, cpsr, old_r */
+	mov	r0, sp
+	.endm
+
+
+	/* use irq_save_user_regs / irq_restore_user_regs for		     */
+	/* IRQ/FIQ handling						     */
+
+	.macro	irq_save_user_regs
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}			/* Calling r0-r12	     */
+	add	r8, sp, #S_PC
+	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_end		@ setup our mode stack
+	add	r13, r13, #CONFIG_STACKSIZE	@ resides at top of normal stack
+	sub	r13, r13, #8
+
+	str	lr, [r13]			@ save caller lr / spsr
+	mrs	lr, spsr
+	str	lr, [r13, #4]
+
+	mov	r13, #MODE_SVC			@ prepare SVC-Mode
+	msr	spsr_c, r13
+	mov	lr, pc
+	movs	pc, lr
+	.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
+	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
+
+#ifdef 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
+	irq_save_user_regs		/* someone ought to write a more    */
+	bl	do_fiq			/* effiction fiq_save_user_regs	    */
+	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
+
+/****************************************************************************/
+/*                                                                          */
+/* Reset function: the PXA250 doesn't have a reset function, so we have to  */
+/* perform a watchdog timeout for a soft reset.                             */
+/*                                                                          */
+/****************************************************************************/
+
+	.align	5
+.globl reset_cpu
+
+	/* FIXME: this code is PXA250 specific. How is this handled on      */
+	/*        other XScale processors?                                  */
+
+reset_cpu:
+
+	/* We set OWE:WME (watchdog enable) and wait until timeout happens  */
+
+	ldr	r0, OSTIMER_BASE
+	ldr	r1, [r0, #OWER]
+	orr	r1, r1, #0x0001			/* bit0: WME                */
+	str	r1, [r0, #OWER]
+
+	/* OS timer does only wrap every 1165 seconds, so we have to set    */
+	/* the match register as well.                                      */
+
+	ldr	r1, [r0, #OSCR]			/* read OS timer            */
+	add	r1, r1, #0x800			/* let OSMR3 match after    */
+	add	r1, r1, #0x800			/* 4096*(1/3.6864MHz)=1ms   */
+	str	r1, [r0, #OSMR3]
+
+reset_endless:
+
+	b	reset_endless
+