[people/ms/u-boot.git] / arch / arc / cpu / arc700 / start.S

/*
 * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <asm-offsets.h>
#include <config.h>
#include <asm/arcregs.h>

/*
 * Note on the LD/ST addressing modes with address register write-back
 *
 * LD.a same as LD.aw
 *
 * LD.a    reg1, [reg2, x]  => Pre Incr
 *      Eff Addr for load = [reg2 + x]
 *
 * LD.ab   reg1, [reg2, x]  => Post Incr
 *      Eff Addr for load = [reg2]
 */

.macro PUSH reg
	st.a	\reg, [%sp, -4]
.endm

.macro PUSHAX aux
	lr	%r9, [\aux]
	PUSH	%r9
.endm

.macro  SAVE_R1_TO_R24
	PUSH	%r1
	PUSH	%r2
	PUSH	%r3
	PUSH	%r4
	PUSH	%r5
	PUSH	%r6
	PUSH	%r7
	PUSH	%r8
	PUSH	%r9
	PUSH	%r10
	PUSH	%r11
	PUSH	%r12
	PUSH	%r13
	PUSH	%r14
	PUSH	%r15
	PUSH	%r16
	PUSH	%r17
	PUSH	%r18
	PUSH	%r19
	PUSH	%r20
	PUSH	%r21
	PUSH	%r22
	PUSH	%r23
	PUSH	%r24
.endm

.macro SAVE_ALL_SYS
	/* saving %r0 to reg->r0 in advance since we read %ecr into it */
	st	%r0, [%sp, -8]
	lr	%r0, [%ecr]	/* all stack addressing is manual so far */
	st	%r0, [%sp]
	st	%sp, [%sp, -4]
	/* now move %sp to reg->r0 position so we can do "push" automatically */
	sub	%sp, %sp, 8

	SAVE_R1_TO_R24
	PUSH	%r25
	PUSH	%gp
	PUSH	%fp
	PUSH	%blink
	PUSHAX	%eret
	PUSHAX	%erstatus
	PUSH	%lp_count
	PUSHAX	%lp_end
	PUSHAX	%lp_start
	PUSHAX	%erbta
.endm

.macro SAVE_EXCEPTION_SOURCE
#ifdef CONFIG_MMU
	/* If MMU exists exception faulting address is loaded in EFA reg */
	lr	%r0, [%efa]
#else
	/* Otherwise in ERET (exception return) reg */
	lr	%r0, [%eret]
#endif
.endm

.align 4
.globl _start
_start:
	/* Critical system events */
	j	reset			/* 0 - 0x000 */
	j	memory_error		/* 1 - 0x008 */
	j	instruction_error	/* 2 - 0x010 */

	/* Device interrupts */
.rept	29
	j	interrupt_handler	/* 3:31 - 0x018:0xF8 */
.endr
	/* Exceptions */
	j	EV_MachineCheck		/* 0x100, Fatal Machine check  (0x20) */
	j	EV_TLBMissI		/* 0x108, Intruction TLB miss  (0x21) */
	j	EV_TLBMissD		/* 0x110, Data TLB miss        (0x22) */
	j	EV_TLBProtV		/* 0x118, Protection Violation (0x23)
							or Misaligned Access  */
	j	EV_PrivilegeV		/* 0x120, Privilege Violation  (0x24) */
	j	EV_Trap			/* 0x128, Trap exception       (0x25) */
	j	EV_Extension		/* 0x130, Extn Intruction Excp (0x26) */

memory_error:
	SAVE_ALL_SYS
	SAVE_EXCEPTION_SOURCE
	mov	%r1, %sp
	j	do_memory_error

instruction_error:
	SAVE_ALL_SYS
	SAVE_EXCEPTION_SOURCE
	mov	%r1, %sp
	j	do_instruction_error

interrupt_handler:
	/* Todo - save and restore CPU context when interrupts will be in use */
	bl	do_interrupt_handler
	rtie

EV_MachineCheck:
	SAVE_ALL_SYS
	SAVE_EXCEPTION_SOURCE
	mov	%r1, %sp
	j	do_machine_check_fault

EV_TLBMissI:
	SAVE_ALL_SYS
	mov	%r0, %sp
	j	do_itlb_miss

EV_TLBMissD:
	SAVE_ALL_SYS
	mov	%r0, %sp
	j	do_dtlb_miss

EV_TLBProtV:
	SAVE_ALL_SYS
	SAVE_EXCEPTION_SOURCE
	mov	%r1, %sp
	j	do_tlb_prot_violation

EV_PrivilegeV:
	SAVE_ALL_SYS
	mov	%r0, %sp
	j	do_privilege_violation

EV_Trap:
	SAVE_ALL_SYS
	mov	%r0, %sp
	j	do_trap

EV_Extension:
	SAVE_ALL_SYS
	mov	%r0, %sp
	j	do_extension


reset:
	/* Setup interrupt vector base that matches "__text_start" */
	sr	__text_start, [ARC_AUX_INTR_VEC_BASE]

	/* Setup stack pointer */
	mov	%sp, CONFIG_SYS_INIT_SP_ADDR
	mov	%fp, %sp

	/* Clear bss */
	mov	%r0, __bss_start
	mov	%r1, __bss_end

clear_bss:
	st.ab	0, [%r0, 4]
	brlt	%r0, %r1, clear_bss

	/* Zero the one and only argument of "board_init_f" */
	mov_s	%r0, 0
	j	board_init_f

/*
 * void relocate_code (addr_sp, gd, addr_moni)
 *
 * This "function" does not return, instead it continues in RAM
 * after relocating the monitor code.
 *
 * r0 = start_addr_sp
 * r1 = new__gd
 * r2 = relocaddr
 */
.align 4
.globl	relocate_code
relocate_code:
	/*
	 * r0-r12 might be clobbered by C functions
	 * so we use r13-r16 for storage here
	 */
	mov	%r13, %r0		/* save addr_sp */
	mov	%r14, %r1		/* save addr of gd */
	mov	%r15, %r2		/* save addr of destination */

	mov	%r16, %r2		/* %r9 - relocation offset */
	sub	%r16, %r16, __image_copy_start

/* Set up the stack */
stack_setup:
	mov	%sp, %r13
	mov	%fp, %sp

/* Check if monitor is loaded right in place for relocation */
	mov	%r0, __image_copy_start
	cmp	%r0, %r15		/* skip relocation if code loaded */
	bz	do_board_init_r		/* in target location already */

/* Copy data (__image_copy_start - __image_copy_end) to new location */
	mov	%r1, %r15
	mov	%r2, __image_copy_end
	sub	%r2, %r2, %r0		/* r3 <- amount of bytes to copy */
	asr	%r2, %r2, 2		/* r3 <- amount of words to copy */
	mov	%lp_count, %r2
	lp	copy_end
	ld.ab	%r2,[%r0,4]
	st.ab	%r2,[%r1,4]
copy_end:

/* Fix relocations related issues */
	bl	do_elf_reloc_fixups
#ifndef CONFIG_SYS_ICACHE_OFF
	bl	invalidate_icache_all
#endif
#ifndef CONFIG_SYS_DCACHE_OFF
	bl	flush_dcache_all
#endif

/* Update position of intterupt vector table */
	lr	%r0, [ARC_AUX_INTR_VEC_BASE]	/* Read current position */
	add	%r0, %r0, %r16			/* Update address */
	sr	%r0, [ARC_AUX_INTR_VEC_BASE]	/* Write new position */

do_board_init_r:
/* Prepare for exection of "board_init_r" in relocated monitor */
	mov	%r2, board_init_r	/* old address of "board_init_r()" */
	add	%r2, %r2, %r16		/* new address of "board_init_r()" */
	mov	%r0, %r14		/* 1-st parameter: gd_t */
	mov	%r1, %r15		/* 2-nd parameter: dest_addr */
	j	[%r2]
Commit	Line	Data
2f16ac9d AB	1	/*
	2	* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
	3	*
	4	* SPDX-License-Identifier: GPL-2.0+
	5	*/
	6
	7	#include <asm-offsets.h>
	8	#include <config.h>
	9	#include <asm/arcregs.h>
	10
	11	/*
	12	* Note on the LD/ST addressing modes with address register write-back
	13	*
	14	* LD.a same as LD.aw
	15	*
	16	* LD.a reg1, [reg2, x] => Pre Incr
	17	* Eff Addr for load = [reg2 + x]
	18	*
	19	* LD.ab reg1, [reg2, x] => Post Incr
	20	* Eff Addr for load = [reg2]
	21	*/
	22
	23	.macro PUSH reg
	24	st.a \reg, [%sp, -4]
	25	.endm
	26
	27	.macro PUSHAX aux
	28	lr %r9, [\aux]
	29	PUSH %r9
	30	.endm
	31
	32	.macro SAVE_R1_TO_R24
	33	PUSH %r1
	34	PUSH %r2
	35	PUSH %r3
	36	PUSH %r4
	37	PUSH %r5
	38	PUSH %r6
	39	PUSH %r7
	40	PUSH %r8
	41	PUSH %r9
	42	PUSH %r10
	43	PUSH %r11
	44	PUSH %r12
	45	PUSH %r13
	46	PUSH %r14
	47	PUSH %r15
	48	PUSH %r16
	49	PUSH %r17
	50	PUSH %r18
	51	PUSH %r19
	52	PUSH %r20
	53	PUSH %r21
	54	PUSH %r22
	55	PUSH %r23
	56	PUSH %r24
	57	.endm
	58
	59	.macro SAVE_ALL_SYS
e47d7338 IG	60	/* saving %r0 to reg->r0 in advance since we read %ecr into it */
	61	st %r0, [%sp, -8]
	62	lr %r0, [%ecr] /* all stack addressing is manual so far */
2f16ac9d	63	st %r0, [%sp]
e47d7338 IG	64	st %sp, [%sp, -4]
	65	/* now move %sp to reg->r0 position so we can do "push" automatically */
	66	sub %sp, %sp, 8
2f16ac9d AB	67
	68	SAVE_R1_TO_R24
	69	PUSH %r25
	70	PUSH %gp
	71	PUSH %fp
	72	PUSH %blink
	73	PUSHAX %eret
	74	PUSHAX %erstatus
	75	PUSH %lp_count
	76	PUSHAX %lp_end
	77	PUSHAX %lp_start
	78	PUSHAX %erbta
	79	.endm
	80
dcb431e7 AB	81	.macro SAVE_EXCEPTION_SOURCE
	82	#ifdef CONFIG_MMU
	83	/* If MMU exists exception faulting address is loaded in EFA reg */
	84	lr %r0, [%efa]
	85	#else
	86	/* Otherwise in ERET (exception return) reg */
	87	lr %r0, [%eret]
	88	#endif
	89	.endm
	90
2f16ac9d AB	91	.align 4
	92	.globl _start
	93	_start:
	94	/* Critical system events */
	95	j reset /* 0 - 0x000 */
	96	j memory_error /* 1 - 0x008 */
	97	j instruction_error /* 2 - 0x010 */
	98
	99	/* Device interrupts */
	100	.rept 29
	101	j interrupt_handler /* 3:31 - 0x018:0xF8 */
	102	.endr
	103	/* Exceptions */
	104	j EV_MachineCheck /* 0x100, Fatal Machine check (0x20) */
	105	j EV_TLBMissI /* 0x108, Intruction TLB miss (0x21) */
	106	j EV_TLBMissD /* 0x110, Data TLB miss (0x22) */
	107	j EV_TLBProtV /* 0x118, Protection Violation (0x23)
	108	or Misaligned Access */
	109	j EV_PrivilegeV /* 0x120, Privilege Violation (0x24) */
	110	j EV_Trap /* 0x128, Trap exception (0x25) */
	111	j EV_Extension /* 0x130, Extn Intruction Excp (0x26) */
	112
	113	memory_error:
	114	SAVE_ALL_SYS
dcb431e7	115	SAVE_EXCEPTION_SOURCE
2f16ac9d AB	116	mov %r1, %sp
	117	j do_memory_error
	118
	119	instruction_error:
	120	SAVE_ALL_SYS
dcb431e7	121	SAVE_EXCEPTION_SOURCE
2f16ac9d AB	122	mov %r1, %sp
	123	j do_instruction_error
	124
	125	interrupt_handler:
	126	/* Todo - save and restore CPU context when interrupts will be in use */
	127	bl do_interrupt_handler
	128	rtie
	129
	130	EV_MachineCheck:
	131	SAVE_ALL_SYS
dcb431e7	132	SAVE_EXCEPTION_SOURCE
2f16ac9d AB	133	mov %r1, %sp
	134	j do_machine_check_fault
	135
	136	EV_TLBMissI:
	137	SAVE_ALL_SYS
	138	mov %r0, %sp
	139	j do_itlb_miss
	140
	141	EV_TLBMissD:
	142	SAVE_ALL_SYS
	143	mov %r0, %sp
	144	j do_dtlb_miss
	145
	146	EV_TLBProtV:
	147	SAVE_ALL_SYS
dcb431e7	148	SAVE_EXCEPTION_SOURCE
2f16ac9d AB	149	mov %r1, %sp
	150	j do_tlb_prot_violation
	151
	152	EV_PrivilegeV:
	153	SAVE_ALL_SYS
	154	mov %r0, %sp
	155	j do_privilege_violation
	156
	157	EV_Trap:
	158	SAVE_ALL_SYS
	159	mov %r0, %sp
	160	j do_trap
	161
	162	EV_Extension:
	163	SAVE_ALL_SYS
	164	mov %r0, %sp
	165	j do_extension
	166
	167
	168	reset:
	169	/* Setup interrupt vector base that matches "__text_start" */
	170	sr __text_start, [ARC_AUX_INTR_VEC_BASE]
	171
	172	/* Setup stack pointer */
	173	mov %sp, CONFIG_SYS_INIT_SP_ADDR
	174	mov %fp, %sp
	175
	176	/* Clear bss */
	177	mov %r0, __bss_start
	178	mov %r1, __bss_end
	179
	180	clear_bss:
	181	st.ab 0, [%r0, 4]
	182	brlt %r0, %r1, clear_bss
	183
	184	/* Zero the one and only argument of "board_init_f" */
	185	mov_s %r0, 0
	186	j board_init_f
	187
	188	/*
	189	* void relocate_code (addr_sp, gd, addr_moni)
	190	*
	191	* This "function" does not return, instead it continues in RAM
	192	* after relocating the monitor code.
	193	*
	194	* r0 = start_addr_sp
	195	* r1 = new__gd
	196	* r2 = relocaddr
	197	*/
	198	.align 4
	199	.globl relocate_code
	200	relocate_code:
	201	/*
	202	* r0-r12 might be clobbered by C functions
	203	* so we use r13-r16 for storage here
	204	*/
	205	mov %r13, %r0 /* save addr_sp */
	206	mov %r14, %r1 /* save addr of gd */
	207	mov %r15, %r2 /* save addr of destination */
	208
	209	mov %r16, %r2 /* %r9 - relocation offset */
	210	sub %r16, %r16, __image_copy_start
	211
	212	/* Set up the stack */
213	stack_setup:
214	mov %sp, %r13
215	mov %fp, %sp
216
217	/* Check if monitor is loaded right in place for relocation */
218	mov %r0, __image_copy_start
219	cmp %r0, %r15 /* skip relocation if code loaded */
220	bz do_board_init_r /* in target location already */
221
222	/* Copy data (__image_copy_start - __image_copy_end) to new location */
223	mov %r1, %r15
224	mov %r2, __image_copy_end
225	sub %r2, %r2, %r0 /* r3 <- amount of bytes to copy */
226	asr %r2, %r2, 2 /* r3 <- amount of words to copy */
227	mov %lp_count, %r2
228	lp copy_end
229	ld.ab %r2,[%r0,4]
230	st.ab %r2,[%r1,4]
231	copy_end:
232
233	/* Fix relocations related issues */
234	bl do_elf_reloc_fixups
235	#ifndef CONFIG_SYS_ICACHE_OFF
236	bl invalidate_icache_all
237	#endif
238	#ifndef CONFIG_SYS_DCACHE_OFF
239	bl flush_dcache_all
240	#endif
241
242	/* Update position of intterupt vector table */
243	lr %r0, [ARC_AUX_INTR_VEC_BASE] /* Read current position */
244	add %r0, %r0, %r16 /* Update address */
245	sr %r0, [ARC_AUX_INTR_VEC_BASE] /* Write new position */
246
247	do_board_init_r:
248	/* Prepare for exection of "board_init_r" in relocated monitor */
249	mov %r2, board_init_r /* old address of "board_init_r()" */
250	add %r2, %r2, %r16 /* new address of "board_init_r()" */
251	mov %r0, %r14 /* 1-st parameter: gd_t */
252	mov %r1, %r15 /* 2-nd parameter: dest_addr */
253	j [%r2]