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authorwdenk <wdenk>2005-01-09 23:16:25 +0000
committerwdenk <wdenk>2005-01-09 23:16:25 +0000
commit8ed9604613398660f9ee855060661da8809d4045 (patch)
tree7901e427798e0d09ad53038d7b6112e10556ceae /cpu/arm1136/start.S
parentff36fd8591776405eeb3a086ba1136bf1ece2ffb (diff)
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* Patches by Richard Woodruff, 01 Oct 2004:
add support for the TI OMAP2420 processor and its H4 reference board * Patch by Christian Pellegrin, 24 Sep 2004: Added support for NE2000 compatible (DP8390, DP83902) NICs.
Diffstat (limited to 'cpu/arm1136/start.S')
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+/*
+ * armboot - Startup Code for OMP2420/ARM1136 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 <gj@denx.de>
+ * Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
+ * Copyright (c) 2003 Kshitij <kshitij@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>
+#include <asm/arch/omap2420.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
+
+#ifdef CONFIG_OMAP2420H4
+ /* Copy vectors to mask ROM indirect addr */
+ adr r0, _start /* r0 <- current position of code */
+ 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 */
+#ifdef CONFIG_PARTIAL_SRAM
+ bl cpy_clk_code /* put dpll adjust code behind vectors */
+#endif
+#endif
+ /* the mask ROM code should have PLL and others stable */
+ bl cpu_init_crit
+
+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:
+ 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, _TEXT_BASE /* upper 128 KiB: relocated uboot */
+ sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
+ sub r0, r0, #CFG_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 */
+
+clear_bss:
+ ldr r0, _bss_start /* find start of bss segment */
+ 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
+ *
+ *************************************************************************
+ */
+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
+#ifndef CONFIG_ICACHE_OFF
+ orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache
+#endif
+ 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.
+ */
+ adr r0, _start /* r0 <- current position of code */
+ ldr r1, _TEXT_BASE /* test if we run from flash or RAM */
+ cmp r0, r1 /* pass on info about skipping some init portions */
+ moveq r0,#0x1 /* flag to skip prcm and sdrc setup */
+ movne r0,#0x0
+ mov ip, lr /* persevere link reg across call */
+ bl platformsetup /* 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, #(CFG_MALLOC_LEN)
+ sub r2, r2, #(CFG_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, #(CFG_MALLOC_LEN) @ move past malloc pool
+ sub r13, r13, #(CFG_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, #(CFG_MALLOC_LEN) @ move past malloc pool
+ sub r0, r0, #(CFG_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 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
+ .align 5
+.global arm1136_cache_flush
+arm1136_cache_flush:
+ mcr p15, 0, r1, c7, c5, 0 @ invalidate I cache
+ mov pc, lr @ back to caller
+
+ .align 5
+.globl reset_cpu
+reset_cpu:
+ ldr r1, rstctl /* get addr for global reset reg */
+ mov r3, #0x3 /* full reset pll+mpu */
+ str r3, [r1] /* force reset */
+ mov r0, r0
+_loop_forever:
+ b _loop_forever
+rstctl:
+ .word PM_RSTCTRL_WKUP