M28: Add MMC SPL

This patch adds SPL code for the M28 board.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>

1 files changed, 396 insertions, 0 deletions

diff --git a/board/denx/m28evk/start.S b/board/denx/m28evk/start.S
new file mode 100644
index 0000000..cf675995
--- /dev/null
+++ b/board/denx/m28evk/start.S
@@ -0,0 +1,396 @@
+/*
+ *  armboot - Startup Code for ARM926EJS CPU-core
+ *
+ *  Copyright (c) 2003  Texas Instruments
+ *
+ *  ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
+ *
+ *  Copyright (c) 2001	Marius Groger <mag@sysgo.de>
+ *  Copyright (c) 2002	Alex Zupke <azu@sysgo.de>
+ *  Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
+ *  Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
+ *  Copyright (c) 2003	Kshitij <kshitij@ti.com>
+ *  Copyright (c) 2010	Albert Aribaud <albert.u.boot@aribaud.net>
+ *
+ * Change to support call back into iMX28 bootrom
+ * Copyright (c) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * 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 <asm-offsets.h>
+#include <config.h>
+#include <common.h>
+#include <version.h>
+
+#if defined(CONFIG_OMAP1610)
+#include <./configs/omap1510.h>
+#elif defined(CONFIG_OMAP730)
+#include <./configs/omap730.h>
+#endif
+
+/*
+ *************************************************************************
+ *
+ * Jump vector table as in table 3.1 in [1]
+ *
+ *************************************************************************
+ */
+
+
+.globl _start
+_start:
+	b	reset
+#ifdef CONFIG_SPL_BUILD
+/* No exception handlers in preloader */
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	ldr	pc, _hang
+	b	reset
+	ldr	pc, _hang
+	ldr	pc, _hang
+
+_hang:
+	.word	do_hang
+/* pad to 64 byte boundary */
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+	.word	0x12345678
+#else
+	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
+
+#endif	/* CONFIG_SPL_BUILD */
+	.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
+ *
+ *************************************************************************
+ */
+
+.globl _TEXT_BASE
+_TEXT_BASE:
+	.word	CONFIG_SYS_TEXT_BASE
+
+/*
+ * These are defined in the board-specific linker script.
+ * Subtracting _start from them lets the linker put their
+ * relative position in the executable instead of leaving
+ * them null.
+ */
+.globl _bss_start_ofs
+_bss_start_ofs:
+	.word __bss_start - _start
+
+.globl _bss_end_ofs
+_bss_end_ofs:
+	.word __bss_end__ - _start
+
+.globl _end_ofs
+_end_ofs:
+	.word _end - _start
+
+#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
+
+/* IRQ stack memory (calculated at run-time) + 8 bytes */
+.globl IRQ_STACK_START_IN
+IRQ_STACK_START_IN:
+	.word	0x0badc0de
+
+/*
+ * the actual reset code
+ */
+
+reset:
+	/*
+	 * Store all registers on old stack pointer, this will allow us later to
+	 * return to the BootROM and let the BootROM load U-Boot into RAM.
+	 */
+	push	{r0-r12,r14}
+
+	/*
+	 * set the cpu to SVC32 mode
+	 */
+	mrs	r0,cpsr
+	bic	r0,r0,#0x1f
+	orr	r0,r0,#0xd3
+	msr	cpsr,r0
+
+	/*
+	 * we do sys-critical inits only at reboot,
+	 * not when booting from ram!
+	 */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+	bl	cpu_init_crit
+#endif
+
+	bl	board_init_ll
+
+	pop	{r0-r12,r14}
+	bx	lr
+
+/*
+ *************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************
+ */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+cpu_init_crit:
+	/*
+	 * flush v4 I/D caches
+	 */
+	mov	r0, #0
+	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
+	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
+
+	/*
+	 * disable MMU stuff and caches
+	 */
+	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
+
+	mov	pc, lr		/* back to my caller */
+#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
+
+#ifndef CONFIG_SPL_BUILD
+/*
+ *************************************************************************
+ *
+ * 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
+	@ carve out a frame on current user stack
+	sub	sp, sp, #S_FRAME_SIZE
+	stmia	sp, {r0 - r12}	@ Save user registers (now in svc mode) r0-r12
+	ldr	r2, IRQ_STACK_START_IN
+	@ get values for "aborted" pc and cpsr (into parm regs)
+	ldmia	r2, {r2 - r3}
+	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
+	@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
+	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, IRQ_STACK_START_IN		@ setup our mode 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_irq_stack			@ setup IRQ stack
+	ldr	sp, IRQ_STACK_START
+	.endm
+
+	.macro get_fiq_stack			@ setup FIQ stack
+	ldr	sp, FIQ_STACK_START
+	.endm
+#endif	/* CONFIG_SPL_BUILD */
+
+/*
+ * exception handlers
+ */
+#ifdef CONFIG_SPL_BUILD
+	.align	5
+do_hang:
+	ldr	sp, _TEXT_BASE			/* switch to abort stack */
+1:
+	bl	1b				/* hang and never return */
+#else	/* !CONFIG_SPL_BUILD */
+	.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
+	/* 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
+#endif	/* CONFIG_SPL_BUILD */