/* * armboot - Startup Code for OMP2420/ARM1136 CPU-core * * Copyright (c) 2004 Texas Instruments * * Copyright (c) 2001 Marius Gröger * Copyright (c) 2002 Alex Züpke * Copyright (c) 2002 Gary Jennejohn * Copyright (c) 2003 Richard Woodruff * Copyright (c) 2003 Kshitij * * 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 #include .section ".text.head", "ax" .globl _start _start: .section ".text.vect", "ax" .global _start_vect _start_vect: #ifdef CONFIG_PRELOADER b reset ldr pc, _hang ldr pc, _hang ldr pc, _hang ldr pc, _hang ldr pc, _hang ldr pc, _hang ldr pc, _hang _hang: .word do_hang .word 0x12345678 .word 0x12345678 .word 0x12345678 .word 0x12345678 .word 0x12345678 .word 0x12345678 .word 0x12345678 /* now 16*4=64 */ #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 _pad: .word 0x12345678 /* now 16*4=64 */ #endif /* CONFIG_PRELOADER */ .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 * ************************************************************************* */ /* * the actual reset code */ .section ".text.head", "ax" .globl reset 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 */ 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 */ bl cpy_clk_code /* put dpll adjust code behind vectors */ #endif /* the mask ROM code should have PLL and others stable */ #ifndef CONFIG_SKIP_LOWLEVEL_INIT bl cpu_init_crit #endif b setup_env /* ************************************************************************* * * 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 orr r0, r0, #0x00001000 @ set bit 12 (I) I-Cache 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 */ .section ".text.setup", "ax" .globl _TEXT_BASE _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 setup_env: #ifndef CONFIG_SKIP_RELOCATE_UBOOT relocate: /* relocate U-Boot to RAM */ adr r0, _armboot_start ldr r1, =_armboot_start cmp r0, r1 /* don't reloc during debug */ beq stack_setup ldr r2, _TEXT_BASE sub r0, r1, r0 sub r0, r2, r0 ldr r1, _TEXT_BASE 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 #endif /* CONFIG_SKIP_RELOCATE_UBOOT */ /* Set up the stack */ stack_setup: ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */ #ifdef CONFIG_PRELOADER sub sp, r0, #128 /* leave 32 words for abort-stack */ #else 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 */ #endif /* CONFIG_PRELOADER */ clear_bss: ldr r0, _bss_start /* find start of bss segment */ ldr r1, _bss_end /* stop here */ mov r2, #0x00000000 /* clear */ #ifndef CONFIG_PRELOADER clbss_l:str r2, [r0] /* clear loop... */ add r0, r0, #4 cmp r0, r1 bne clbss_l #endif ldr pc, _start_armboot #ifdef CONFIG_NAND_SPL _start_armboot: .word nand_boot #else #ifdef CONFIG_ONENAND_IPL _start_armboot: .word start_oneboot #else _start_armboot: .word start_armboot #endif /* CONFIG_ONENAND_IPL */ #endif /* CONFIG_NAND_SPL */ /* ************************************************************************* * * 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 /* * 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 */ #endif /* CONFIG_SKIP_LOWLEVEL_INIT */ #ifndef CONFIG_PRELOADER /* ************************************************************************* * * 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 #endif /* CONFIG_PRELOADER */ /* * exception handlers */ #ifdef CONFIG_PRELOADER .align 5 do_hang: ldr sp, _TEXT_BASE /* use 32 words about stack */ bl hang /* hang and never return */ #else /* !CONFIG_PRELOADER */ .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 #endif /* CONFIG_PRELOADER */