[mini2440]add start_gcc.s for gcc version

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@385 bbd45198-f89e-11dd-88c7-29a3b14d5316

libcpu/arm/s3c24x0/start_gcc.s

+/*
+ * File      : start.S
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006, RT-Thread Development Team
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://openlab.rt-thread.com/license/LICENSE
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2006-03-13     Bernard      first version
+ * 2006-10-05     Alsor.Z      for s3c2410 initialize
+ * 2008-01-29     Yi.Qiu       for QEMU emulator
+ */
+
+/**
+ * @addtogroup S3C2410
+ */
+/*@{*/
+
+#define CONFIG_STACKSIZE 512
+#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
+
+	.equ USERMODE, 	0x10
+	.equ FIQMODE,	0x11
+	.equ IRQMODE,	0x12
+	.equ SVCMODE,	0x13
+	.equ ABORTMODE,	0x17
+	.equ UNDEFMODE,	0x1b
+	.equ MODEMASK,	0x1f
+	.equ NOINT,		0xc0
+
+.section .init, "ax"
+.code 32
+.globl _start
+_start:
+	b	reset
+	ldr	pc, _vector_undef
+	ldr	pc, _vector_swi
+	ldr	pc, _vector_pabt
+	ldr	pc, _vector_dabt
+	ldr	pc, _vector_resv
+	ldr	pc, _vector_irq
+	ldr	pc, _vector_fiq
+
+_vector_undef:	.word vector_undef
+_vector_swi:	.word vector_swi
+_vector_pabt:	.word vector_pabt
+_vector_dabt:	.word vector_dabt
+_vector_resv:	.word vector_resv
+_vector_irq:	.word vector_irq
+_vector_fiq:	.word vector_fiq
+
+	.balignl 16,0xdeadbeef
+
+_TEXT_BASE:
+	.word	TEXT_BASE
+
+/*
+ * rtthread kernel start and end
+ * which are defined in linker script
+ */
+.globl _rtthread_start
+_rtthread_start:.word _start
+.globl _rtthread_end
+_rtthread_end:	.word  _end
+
+/*
+ * rtthread bss start and end
+ * which are defined in linker script
+ */
+.globl _bss_start
+_bss_start:	.word __bss_start
+.globl _bss_end
+_bss_end:	.word __bss_end
+
+/* IRQ stack memory (calculated at run-time) */
+.globl IRQ_STACK_START
+IRQ_STACK_START:.word _irq_stack_start + 1024
+.globl FIQ_STACK_START
+FIQ_STACK_START:.word _fiq_stack_start + 1024
+.globl UNDEFINED_STACK_START
+UNDEFINED_STACK_START:.word _undefined_stack_start + CONFIG_STACKSIZE
+.globl ABORT_STACK_START
+ABORT_STACK_START:.word _abort_stack_start + CONFIG_STACKSIZE
+.globl _STACK_START
+_STACK_START:.word _svc_stack_start + 4096
+
+	.equ RAM_BASE,	0x00000000	//Start address of RAM
+	.equ ROM_BASE,	0x30000000	//Start address of Flash
+
+	.equ INTMSK,	0x4a000008
+	.equ WTCON, 	0x53000000
+	.equ INTSUBMSK, 0x4a00001c
+	.equ LOCKTIME,	0x4c000000
+
+	.equ MPLLCON,	0x4c000004
+	.equ M_MDIV,	0x20
+	.equ M_PDIV,	0x4
+	.equ M_SDIV,	0x2
+	.equ CLKDIVN,	0x4c000014	//Clock divider control
+	.equ GPHCON,	0x56000070	//Port H control
+	.equ GPHUP,		0x56000078	//Pull-up control H
+	.equ BWSCON,	0x48000000	//Bus width & wait status
+	.equ BANKCON0,	0x48000004	//Boot ROM control
+	.equ BANKCON1,	0x48000008	//BANK1 control
+	.equ BANKCON2,	0x4800000c	//BANK2 cControl
+	.equ BANKCON3,	0x48000010	//BANK3 control
+	.equ BANKCON4,	0x48000014	//BANK4 control
+	.equ BANKCON5,	0x48000018	//BANK5 control
+	.equ BANKCON6,	0x4800001c	//BANK6 control
+	.equ BANKCON7,	0x48000020	//BANK7 control
+	.equ REFRESH,	0x48000024	//DRAM/SDRAM efresh
+	.equ BANKSIZE,	0x48000028	//Flexible Bank Size
+	.equ MRSRB6,	0x4800002c	//Mode egister set for SDRAM
+	.equ MRSRB7,	0x48000030	//Mode egister set for SDRAM
+
+/* -----------------entry--------------- */
+reset:
+	/* watch dog disable */
+	ldr r0,=WTCON
+	ldr r1,=0x0
+	str r1,[r0]
+
+	/* set the cpu to SVC32 mode */
+	mrs	r0,cpsr
+	bic	r0,r0,#MODEMASK
+	orr	r0,r0,#SVCMODE
+	msr	cpsr,r0
+
+	/* mask all IRQs by clearing all bits in the INTMRs */
+	ldr	r1, =INTMSK
+	ldr	r0, =0xffffffff
+	str	r0, [r1]
+
+	/* set interrupt vector 	*/
+	ldr r0, _load_address
+	mov	r1, #0x0				/* target address    		*/
+	add	r2, r0, #0x20			/* size, 32bytes         	*/
+
+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
+
+	/* setup stack */
+	bl	stack_setup
+
+	/* clear .bss */
+	mov   r0,#0                     /* get a zero 				*/
+	ldr   r1,=__bss_start           /* bss start 				*/
+	ldr   r2,=__bss_end           	/* bss end 					*/
+bss_loop:
+	cmp   r1,r2                     /* check if data to clear 	*/
+	strlo r0,[r1],#4                /* clear 4 bytes 			*/
+	blo   bss_loop                  /* loop until done 			*/
+
+	/* call C++ constructors of global objects */
+	ldr 	r0, =__ctors_start__
+	ldr 	r1, =__ctors_end__
+ctor_loop:
+	cmp 	r0, r1
+	beq 	ctor_end
+	ldr 	r2, [r0], #4
+	stmfd 	sp!, {r0-r1}
+	mov 	lr, pc
+	bx 		r2
+	ldmfd 	sp!, {r0-r1}
+	b	ctor_loop
+ctor_end:
+
+	/* start RT-Thread Kernel */
+	ldr	pc, _rtthread_startup
+
+_rtthread_startup: .word rtthread_startup
+#if defined (__FLASH_BUILD__)
+_load_address: .word ROM_BASE + _TEXT_BASE
+#else
+_load_address: .word RAM_BASE + _TEXT_BASE
+#endif
+
+/*
+ *************************************************************************
+ *
+ * Interrupt handling
+ *
+ *************************************************************************
+ */
+
+/* exception handlers */
+	.align  5
+vector_undef:
+	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
+
+	bl	rt_hw_trap_udef
+
+	.align	5
+vector_swi:
+	bl 	rt_hw_trap_swi
+
+	.align	5
+vector_pabt:
+	bl 	rt_hw_trap_pabt
+
+	.align	5
+vector_dabt:
+	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
+
+	bl 	rt_hw_trap_dabt
+
+	.align	5
+vector_resv:
+	bl 	rt_hw_trap_resv
+
+.globl rt_interrupt_enter
+.globl rt_interrupt_leave
+.globl rt_thread_switch_interrput_flag
+.globl rt_interrupt_from_thread
+.globl rt_interrupt_to_thread
+vector_irq:
+	stmfd	sp!, {r0-r12,lr}
+	bl	rt_interrupt_enter
+	bl	rt_hw_trap_irq
+	bl	rt_interrupt_leave
+
+	/* if rt_thread_switch_interrput_flag set, jump to _interrupt_thread_switch and don't return */
+	ldr	r0, =rt_thread_switch_interrput_flag
+	ldr	r1, [r0]
+	cmp	r1, #1
+	beq	_interrupt_thread_switch
+
+	ldmfd	sp!, {r0-r12,lr}
+	subs	pc, lr, #4
+
+	.align	5
+vector_fiq:
+	stmfd	sp!,{r0-r7,lr}
+	bl 	rt_hw_trap_fiq
+	ldmfd	sp!,{r0-r7,lr}
+	subs	pc,lr,#4
+
+_interrupt_thread_switch:
+	mov	r1,  #0				@ clear rt_thread_switch_interrput_flag
+	str	r1,  [r0]
+
+	ldmfd	sp!, {r0-r12,lr}@ reload saved registers
+	stmfd	sp!, {r0-r3}	@ save r0-r3
+	mov	r1,  sp
+	add	sp,  sp, #16		@ restore sp
+	sub	r2,  lr, #4			@ save old task's pc to r2
+
+	mrs	r3,  spsr			@ disable interrupt
+	orr	r0,  r3, #NOINT
+	msr	spsr_c, r0
+
+	ldr	r0,  =.+8			@ switch to interrupted task's stack
+	movs	pc,  r0
+
+	stmfd	sp!, {r2}		@ push old task's pc
+	stmfd	sp!, {r4-r12,lr}@ push old task's lr,r12-r4
+	mov	r4,  r1				@ Special optimised code below
+	mov	r5,  r3
+	ldmfd	r4!, {r0-r3}
+	stmfd	sp!, {r0-r3}	@ push old task's r3-r0
+	stmfd	sp!, {r5}		@ push old task's psr
+	mrs	r4,  spsr
+	stmfd	sp!, {r4}		@ push old task's spsr
+
+	ldr	r4,  =rt_interrupt_from_thread
+	ldr	r5,  [r4]
+	str	sp,  [r5]			@ store sp in preempted tasks's TCB
+
+	ldr	r6,  =rt_interrupt_to_thread
+	ldr	r6,  [r6]
+	ldr	sp,  [r6]			@ get new task's stack pointer
+
+	ldmfd	sp!, {r4}		@ pop new task's spsr
+	msr	SPSR_cxsf, r4
+	ldmfd	sp!, {r4}		@ pop new task's psr
+	msr	CPSR_cxsf, r4
+
+	ldmfd	sp!, {r0-r12,lr,pc}	@ pop new task's r0-r12,lr & pc
+
+stack_setup:
+	mrs	r0, cpsr
+	bic	r0, r0, #MODEMASK
+	orr	r1, r0, #UNDEFMODE|NOINT
+	msr	cpsr_cxsf, r1		@ undef mode
+	ldr	sp, UNDEFINED_STACK_START
+
+	orr	r1,r0,#ABORTMODE|NOINT
+	msr	cpsr_cxsf,r1		@ abort mode
+	ldr	sp, ABORT_STACK_START
+
+	orr	r1,r0,#IRQMODE|NOINT
+	msr	cpsr_cxsf,r1		@ IRQ mode
+	ldr	sp, IRQ_STACK_START
+
+	orr	r1,r0,#FIQMODE|NOINT
+	msr	cpsr_cxsf,r1		@ FIQ mode
+	ldr	sp, FIQ_STACK_START
+
+	bic	r0,r0,#MODEMASK
+	orr	r1,r0,#SVCMODE|NOINT
+	msr	cpsr_cxsf,r1		@ SVC mode
+
+	ldr	sp, _STACK_START
+
+	/* USER mode is not initialized. */
+
+	mov	pc,lr				@ The LR register may be not valid for the mode changes.
+
+/*@}*/