--- /dev/null
+/*
+ * armboot - Startup Code for ARM920 CPU-core
+ *
+ * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
+ * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
+ * Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <asm-offsets.h>
+#include <common.h>
+#include <config.h>
+
+/*
+ *************************************************************************
+ *
+ * Jump vector table as in table 3.1 in [1]
+ *
+ *************************************************************************
+ */
+
+
+.globl _start
+_start: b start_code
+ 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
+
+ .balignl 16,0xdeadbeef
+
+
+/*
+ *************************************************************************
+ *
+ * Startup Code (called from the ARM reset exception vector)
+ *
+ * do important init only if we don't start from memory!
+ * relocate armboot to ram
+ * setup stack
+ * jump to second stage
+ *
+ *************************************************************************
+ */
+
+#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 start code
+ */
+
+start_code:
+ /*
+ * set the cpu to SVC32 mode
+ */
+ mrs r0, cpsr
+ bic r0, r0, #0x1f
+ orr r0, r0, #0xd3
+ msr cpsr, r0
+
+#if defined(CONFIG_AT91RM9200DK) || defined(CONFIG_AT91RM9200EK)
+ /*
+ * relocate exception table
+ */
+ ldr r0, =_start
+ ldr r1, =0x0
+ mov r2, #16
+copyex:
+ subs r2, r2, #1
+ ldr r3, [r0], #4
+ str r3, [r1], #4
+ bne copyex
+#endif
+
+#ifdef CONFIG_S3C24X0
+ /* turn off the watchdog */
+
+# if defined(CONFIG_S3C2400)
+# define pWTCON 0x15300000
+# define INTMSK 0x14400008 /* Interrupt-Controller base addresses */
+# define CLKDIVN 0x14800014 /* clock divisor register */
+#else
+# define pWTCON 0x53000000
+# define INTMSK 0x4A000008 /* Interrupt-Controller base addresses */
+# define INTSUBMSK 0x4A00001C
+# define CLKDIVN 0x4C000014 /* clock divisor register */
+# endif
+
+ ldr r0, =pWTCON
+ mov r1, #0x0
+ str r1, [r0]
+
+ /*
+ * mask all IRQs by setting all bits in the INTMR - default
+ */
+ mov r1, #0xffffffff
+ ldr r0, =INTMSK
+ str r1, [r0]
+# if defined(CONFIG_S3C2410)
+ ldr r1, =0x3ff
+ ldr r0, =INTSUBMSK
+ str r1, [r0]
+# endif
+
+ /* FCLK:HCLK:PCLK = 1:2:4 */
+ /* default FCLK is 120 MHz ! */
+ ldr r0, =CLKDIVN
+ mov r1, #3
+ str r1, [r0]
+#endif /* CONFIG_S3C24X0 */
+
+ /*
+ * we do sys-critical inits only at reboot,
+ * not when booting from ram!
+ */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+ bl cpu_init_crit
+#endif
+
+ bl _main
+
+/*------------------------------------------------------------------------------*/
+
+ .globl c_runtime_cpu_setup
+c_runtime_cpu_setup:
+
+ mov pc, 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
+
+ /*
+ * before relocating, we have to setup RAM timing
+ * because memory timing is board-dependend, you will
+ * find a lowlevel_init.S in your board directory.
+ */
+ mov ip, lr
+
+ bl lowlevel_init
+
+ mov lr, ip
+ mov pc, lr
+#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
+
+/*
+ *************************************************************************
+ *
+ * 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
+ stmia sp, {r0 - r12} @ Calling r0-r12
+ ldr r2, IRQ_STACK_START_IN
+ ldmia r2, {r2 - r3} @ get pc, cpsr
+ add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
+
+ add r5, sp, #S_SP
+ mov r1, lr
+ stmia r5, {r0 - r3} @ save sp_SVC, lr_SVC, pc, cpsr
+ mov r0, sp
+ .endm
+
+ .macro irq_save_user_regs
+ sub sp, sp, #S_FRAME_SIZE
+ stmia sp, {r0 - r12} @ Calling r0-r12
+ add r7, sp, #S_PC
+ stmdb r7, {sp, lr}^ @ Calling SP, LR
+ str lr, [r7, #0] @ Save calling PC
+ mrs r6, spsr
+ str r6, [r7, #4] @ Save CPSR
+ str r0, [r7, #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
+ /* return & move spsr_svc into cpsr */
+ subs pc, lr, #4
+ .endm
+
+ .macro get_bad_stack
+ ldr r13, IRQ_STACK_START_IN @ setup our mode stack
+
+ str lr, [r13] @ save caller lr / spsr
+ mrs lr, spsr
+ str lr, [r13, #4]
+
+ mov r13, #MODE_SVC @ prepare SVC-Mode
+ @ msr spsr_c, r13
+ msr spsr, r13
+ mov lr, pc
+ movs pc, lr
+ .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
+ 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
Code Review / kvmfornfv.git / blobdiff