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+/*
+ * armboot - Startup Code for OMAP3530/ARM Cortex CPU-core
+ *
+ * Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com>
+ *
+ * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
+ * Copyright (c) 2002 Alex Züpke <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) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
+ *
+ * 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
+_pad: .word 0x12345678 /* now 16*4=64 */
+.global _end_vect
+_end_vect:
+
+ .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
+ *
+ *************************************************************************/
+
+_TEXT_BASE:
+ .word TEXT_BASE
+
+.globl _armboot_start
+_armboot_start:
+ .word _start
+
+/*
+ * These are defined in the board-specific linker script.
+ */
+.globl _bss_start
+_bss_start:
+ .word __bss_start
+
+.globl _bss_end
+_bss_end:
+ .word _end
+
+#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:
+ /*
+ * set the cpu to SVC32 mode
+ */
+ mrs r0, cpsr
+ bic r0, r0, #0x1f
+ orr r0, r0, #0xd3
+ msr cpsr,r0
+
+#if (CONFIG_OMAP34XX)
+ /* Copy vectors to mask ROM indirect addr */
+ adr r0, _start @ r0 <- current position of code
+ add r0, r0, #4 @ skip reset vector
+ mov r2, #64 @ r2 <- size to copy
+ add r2, r0, r2 @ r2 <- source end address
+ mov r1, #SRAM_OFFSET0 @ build vect addr
+ mov r3, #SRAM_OFFSET1
+ add r1, r1, r3
+ mov r3, #SRAM_OFFSET2
+ add r1, r1, r3
+next:
+ ldmia r0!, {r3 - r10} @ copy from source address [r0]
+ stmia r1!, {r3 - r10} @ copy to target address [r1]
+ cmp r0, r2 @ until source end address [r2]
+ bne next @ loop until equal */
+#if !defined(CONFIG_SYS_NAND_BOOT) && !defined(CONFIG_SYS_ONENAND_BOOT)
+ /* No need to copy/exec the clock code - DPLL adjust already done
+ * in NAND/oneNAND Boot.
+ */
+ bl cpy_clk_code @ put dpll adjust code behind vectors
+#endif /* NAND Boot */
+#endif
+ /* the mask ROM code should have PLL and others stable */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+ bl cpu_init_crit
+#endif
+
+#ifndef CONFIG_SKIP_RELOCATE_UBOOT
+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, _bss_start
+ sub r2, r3, r2 @ r2 <- size of armboot
+ add r2, r0, r2 @ r2 <- source end address
+
+copy_loop: @ copy 32 bytes at a time
+ 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
+#endif /* CONFIG_SKIP_RELOCATE_UBOOT */
+
+ /* Set up the stack */
+stack_setup:
+ ldr r0, _TEXT_BASE @ upper 128 KiB: relocated uboot
+ sub r0, r0, #CONFIG_SYS_MALLOC_LEN @ malloc area
+ sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE @ bdinfo
+#ifdef CONFIG_USE_IRQ
+ sub r0, r0, #(CONFIG_STACKSIZE_IRQ + CONFIG_STACKSIZE_FIQ)
+#endif
+ sub sp, r0, #12 @ leave 3 words for abort-stack
+ bic sp, sp, #7 @ 8-byte alignment for ABI compliance
+
+ /* Clear BSS (if any). Is below tx (watch load addr - need space) */
+clear_bss:
+ ldr r0, _bss_start @ find start of bss segment
+ ldr r1, _bss_end @ stop here
+ mov r2, #0x00000000 @ clear value
+clbss_l:
+ str r2, [r0] @ clear BSS location
+ cmp r0, r1 @ are we at the end yet
+ add r0, r0, #4 @ increment clear index pointer
+ bne clbss_l @ keep clearing till at end
+
+ ldr pc, _start_armboot @ jump to C code
+
+_start_armboot: .word start_armboot
+
+
+/*************************************************************************
+ *
+ * CPU_init_critical registers
+ *
+ * setup important registers
+ * setup memory timing
+ *
+ *************************************************************************/
+cpu_init_crit:
+ /*
+ * Invalidate L1 I/D
+ */
+ mov r0, #0 @ set up for MCR
+ mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
+
+ /*
+ * disable MMU stuff and caches
+ */
+ mrc p15, 0, r0, c1, c0, 0
+ bic r0, r0, #0x00002000 @ clear bits 13 (--V-)
+ bic r0, r0, #0x00000007 @ clear bits 2:0 (-CAM)
+ orr r0, r0, #0x00000002 @ set bit 1 (--A-) Align
+ orr r0, r0, #0x00000800 @ set bit 12 (Z---) BTB
+ mcr p15, 0, r0, c1, c0, 0
+
+ /*
+ * Jump to board specific initialization...
+ * The Mask ROM will have already initialized
+ * basic memory. Go here to bump up clock rate and handle
+ * wake up conditions.
+ */
+ mov ip, lr @ persevere link reg across call
+ bl lowlevel_init @ go setup pll,mux,memory
+ mov lr, ip @ restore link
+ mov pc, lr @ back to my caller
+/*
+ *************************************************************************
+ *
+ * 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
+ sub sp, sp, #S_FRAME_SIZE @ carve out a frame on current
+ @ user stack
+ stmia sp, {r0 - r12} @ Save user registers (now in
+ @ svc mode) r0-r12
+
+ ldr r2, _armboot_start
+ sub r2, r2, #(CONFIG_SYS_MALLOC_LEN)
+ sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE + 8) @ set base 2 words into abort
+ @ stack
+ ldmia r2, {r2 - r3} @ get values for "aborted" pc
+ @ and cpsr (into parm regs)
+ 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
+ add r8, sp, #S_PC @ !! R8 NEEDS to be saved !!
+ @ a reserved stack spot would
+ @ be good.
+ 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_start @ setup our mode stack (enter
+ @ in banked mode)
+ sub r13, r13, #(CONFIG_SYS_MALLOC_LEN) @ move past malloc pool
+ sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE + 8) @ move to reserved a couple
+ @ spots for abort 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_bad_stack_swi
+ sub r13, r13, #4 @ space on current stack for
+ @ scratch reg.
+ str r0, [r13] @ save R0's value.
+ ldr r0, _armboot_start @ get data regions start
+ sub r0, r0, #(CONFIG_SYS_MALLOC_LEN) @ move past malloc pool
+ sub r0, r0, #(CONFIG_SYS_GBL_DATA_SIZE + 8) @ move past gbl and a couple
+ @ spots for abort stack
+ str lr, [r0] @ save caller lr in position 0
+ @ of saved stack
+ mrs r0, spsr @ get the spsr
+ str lr, [r0, #4] @ save spsr in position 1 of
+ @ saved stack
+ ldr r0, [r13] @ restore r0
+ add r13, r13, #4 @ pop stack entry
+ .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_swi
+ 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 effective 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