diff options
Diffstat (limited to 'cpu/arm926ejs')
| -rw-r--r-- | cpu/arm926ejs/Makefile | 43 | ||||
| -rw-r--r-- | cpu/arm926ejs/config.mk | 27 | ||||
| -rw-r--r-- | cpu/arm926ejs/cpu.c | 159 | ||||
| -rw-r--r-- | cpu/arm926ejs/interrupts.c | 293 | ||||
| -rw-r--r-- | cpu/arm926ejs/start.S | 426 |
5 files changed, 948 insertions, 0 deletions
diff --git a/cpu/arm926ejs/Makefile b/cpu/arm926ejs/Makefile new file mode 100644 index 0000000..203278e --- /dev/null +++ b/cpu/arm926ejs/Makefile @@ -0,0 +1,43 @@ +# +# (C) Copyright 2000-2003 +# Wolfgang Denk, DENX Software Engineering, wd@denx.de. +# +# 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 $(TOPDIR)/config.mk + +LIB = lib$(CPU).a + +START = start.o +OBJS = interrupts.o cpu.o + +all: .depend $(START) $(LIB) + +$(LIB): $(OBJS) + $(AR) crv $@ $(OBJS) + +######################################################################### + +.depend: Makefile $(START:.o=.S) $(OBJS:.o=.c) + $(CC) -M $(CFLAGS) $(START:.o=.S) $(OBJS:.o=.c) > $@ + +sinclude .depend + +######################################################################### diff --git a/cpu/arm926ejs/config.mk b/cpu/arm926ejs/config.mk new file mode 100644 index 0000000..cef7d26 --- /dev/null +++ b/cpu/arm926ejs/config.mk @@ -0,0 +1,27 @@ +# +# (C) Copyright 2002 +# Gary Jennejohn, DENX Software Engineering, <gj@denx.de> +# +# 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 +# + +PLATFORM_RELFLAGS += -fno-strict-aliasing -fno-common -ffixed-r8 \ + -mshort-load-bytes -msoft-float + +PLATFORM_CPPFLAGS += -mapcs-32 -march=armv4 diff --git a/cpu/arm926ejs/cpu.c b/cpu/arm926ejs/cpu.c new file mode 100644 index 0000000..a91aa37 --- /dev/null +++ b/cpu/arm926ejs/cpu.c @@ -0,0 +1,159 @@ +/* + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> + * + * 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 + */ + +/* + * CPU specific code + */ + +#include <common.h> +#include <command.h> +#include <arm926ejs.h> + +/* read co-processor 15, register #1 (control register) */ +static unsigned long read_p15_c1 (void) +{ + unsigned long value; + + __asm__ __volatile__( + "mrc p15, 0, %0, c1, c0, 0 @ read control reg\n" + : "=r" (value) + : + : "memory"); + +#ifdef MMU_DEBUG + printf ("p15/c1 is = %08lx\n", value); +#endif + return value; +} + +/* write to co-processor 15, register #1 (control register) */ +static void write_p15_c1 (unsigned long value) +{ +#ifdef MMU_DEBUG + printf ("write %08lx to p15/c1\n", value); +#endif + __asm__ __volatile__( + "mcr p15, 0, %0, c1, c0, 0 @ write it back\n" + : + : "r" (value) + : "memory"); + + read_p15_c1 (); +} + +static void cp_delay (void) +{ + volatile int i; + + /* Many OMAP regs need at least 2 nops */ + for (i = 0; i < 100; i++); +} + +/* See also ARM Ref. Man. */ +#define C1_MMU (1<<0) /* mmu off/on */ +#define C1_ALIGN (1<<1) /* alignment faults off/on */ +#define C1_DC (1<<2) /* dcache off/on */ +#define C1_WB (1<<3) /* merging write buffer on/off */ +#define C1_BIG_ENDIAN (1<<7) /* big endian off/on */ +#define C1_SYS_PROT (1<<8) /* system protection */ +#define C1_ROM_PROT (1<<9) /* ROM protection */ +#define C1_IC (1<<12) /* icache off/on */ +#define C1_HIGH_VECTORS (1<<13) /* location of vectors: low/high addresses */ +#define RESERVED_1 (0xf << 3) /* must be 111b for R/W */ + +int cpu_init (void) +{ + /* + * setup up stack if necessary + */ +#ifdef CONFIG_USE_IRQ + IRQ_STACK_START = _armboot_end + + CONFIG_STACKSIZE + CONFIG_STACKSIZE_IRQ - 4; + FIQ_STACK_START = IRQ_STACK_START + CONFIG_STACKSIZE_FIQ; + _armboot_real_end = FIQ_STACK_START + 4; +#else + _armboot_real_end = _armboot_end + CONFIG_STACKSIZE; +#endif /* CONFIG_USE_IRQ */ + return (0); +} + +int cleanup_before_linux (void) +{ + /* + * this function is called just before we call linux + * it prepares the processor for linux + * + * we turn off caches etc ... + */ + + unsigned long i; + + disable_interrupts (); + + /* turn off I/D-cache */ + asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i)); + i &= ~(C1_DC | C1_IC); + asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i)); + + /* flush I/D-cache */ + i = 0; + asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i)); + return (0); +} + +int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{ + extern void reset_cpu (ulong addr); + + disable_interrupts (); + reset_cpu (0); + /*NOTREACHED*/ + return (0); +} + +void icache_enable (void) +{ + ulong reg; + + reg = read_p15_c1 (); /* get control reg. */ + cp_delay (); + write_p15_c1 (reg | C1_IC); +} + +void icache_disable (void) +{ + ulong reg; + + reg = read_p15_c1 (); + cp_delay (); + write_p15_c1 (reg & ~C1_IC); +} + +int icache_status (void) +{ + return (read_p15_c1 () & C1_IC) != 0; +} diff --git a/cpu/arm926ejs/interrupts.c b/cpu/arm926ejs/interrupts.c new file mode 100644 index 0000000..c0086dd --- /dev/null +++ b/cpu/arm926ejs/interrupts.c @@ -0,0 +1,293 @@ +/* + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * (C) Copyright 2002 + * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> + * + * 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 <common.h> +#include <arm925t.h> +#include <configs/omap1510.h> + +#include <asm/proc-armv/ptrace.h> + +extern void reset_cpu(ulong addr); +#define TIMER_LOAD_VAL 0xffffffff + +/* macro to read the 32 bit timer */ +#define READ_TIMER (*(volatile ulong *)(CFG_TIMERBASE+8)) + +#ifdef CONFIG_USE_IRQ +/* enable IRQ interrupts */ +void enable_interrupts (void) +{ + unsigned long temp; + __asm__ __volatile__("mrs %0, cpsr\n" + "bic %0, %0, #0x80\n" + "msr cpsr_c, %0" + : "=r" (temp) + : "memory"); +} + +/* + * disable IRQ/FIQ interrupts + * returns true if interrupts had been enabled before we disabled them + */ +int disable_interrupts (void) +{ + unsigned long old,temp; + __asm__ __volatile__("mrs %0, cpsr\n" + "orr %1, %0, #0xc0\n" + "msr cpsr_c, %1" + : "=r" (old), "=r" (temp) + : "memory"); + return (old & 0x80) == 0; +} +#else +void enable_interrupts (void) +{ + return; +} +int disable_interrupts (void) +{ + return 0; +} +#endif + + + +void bad_mode (void) +{ + panic ("Resetting CPU ...\n"); + reset_cpu (0); +} + +void show_regs (struct pt_regs *regs) +{ + unsigned long flags; + const char *processor_modes[] = { + "USER_26", "FIQ_26", "IRQ_26", "SVC_26", + "UK4_26", "UK5_26", "UK6_26", "UK7_26", + "UK8_26", "UK9_26", "UK10_26", "UK11_26", + "UK12_26", "UK13_26", "UK14_26", "UK15_26", + "USER_32", "FIQ_32", "IRQ_32", "SVC_32", + "UK4_32", "UK5_32", "UK6_32", "ABT_32", + "UK8_32", "UK9_32", "UK10_32", "UND_32", + "UK12_32", "UK13_32", "UK14_32", "SYS_32", + }; + + flags = condition_codes (regs); + + printf ("pc : [<%08lx>] lr : [<%08lx>]\n" + "sp : %08lx ip : %08lx fp : %08lx\n", + instruction_pointer (regs), + regs->ARM_lr, regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); + printf ("r10: %08lx r9 : %08lx r8 : %08lx\n", + regs->ARM_r10, regs->ARM_r9, regs->ARM_r8); + printf ("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", + regs->ARM_r7, regs->ARM_r6, regs->ARM_r5, regs->ARM_r4); + printf ("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", + regs->ARM_r3, regs->ARM_r2, regs->ARM_r1, regs->ARM_r0); + printf ("Flags: %c%c%c%c", + flags & CC_N_BIT ? 'N' : 'n', + flags & CC_Z_BIT ? 'Z' : 'z', + flags & CC_C_BIT ? 'C' : 'c', flags & CC_V_BIT ? 'V' : 'v'); + printf (" IRQs %s FIQs %s Mode %s%s\n", + interrupts_enabled (regs) ? "on" : "off", + fast_interrupts_enabled (regs) ? "on" : "off", + processor_modes[processor_mode (regs)], + thumb_mode (regs) ? " (T)" : ""); +} + +void do_undefined_instruction (struct pt_regs *pt_regs) +{ + printf ("undefined instruction\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_software_interrupt (struct pt_regs *pt_regs) +{ + printf ("software interrupt\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_prefetch_abort (struct pt_regs *pt_regs) +{ + printf ("prefetch abort\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_data_abort (struct pt_regs *pt_regs) +{ + printf ("data abort\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_not_used (struct pt_regs *pt_regs) +{ + printf ("not used\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_fiq (struct pt_regs *pt_regs) +{ + printf ("fast interrupt request\n"); + show_regs (pt_regs); + bad_mode (); +} + +void do_irq (struct pt_regs *pt_regs) +{ + printf ("interrupt request\n"); + show_regs (pt_regs); + bad_mode (); +} + +static ulong timestamp; +static ulong lastdec; + +/* nothing really to do with interrupts, just starts up a counter. */ +int interrupt_init (void) +{ + int32_t val; + + *((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL; + val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | + (CFG_PVT << MPUTIM_PTV_BIT); + *((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val; + return (0); +} + +/* + * timer without interrupts + */ + +void reset_timer (void) +{ + reset_timer_masked (); +} + +ulong get_timer (ulong base) +{ + return get_timer_masked () - base; +} + +void set_timer (ulong t) +{ + timestamp = t; +} + +/* very rough timer... */ +void udelay (unsigned long usec) +{ +#ifdef CONFIG_INNOVATOROMAP1610 +#define LOOPS_PER_MSEC 100 /* tuned on omap1610 */ + volatile int i, time_remaining = LOOPS_PER_MSEC * usec; + + for (i = time_remaining; i > 0; i--) { + } +#else + + ulong tmo; + tmo = usec / 1000; + tmo *= CFG_HZ; + tmo /= 1000; + tmo += get_timer (0); + while (get_timer_masked () < tmo) + /*NOP*/; +#endif +} + +void reset_timer_masked (void) +{ + /* reset time */ + lastdec = READ_TIMER; + timestamp = 0; +} + +ulong get_timer_masked (void) +{ + ulong now = READ_TIMER; /* current tick value */ + + if (lastdec >= now) { /* did I roll (rem decrementer) */ + /* normal mode */ + /* record amount of time since last check */ + timestamp += lastdec - now; + } else { + /* we have an overflow ... */ + timestamp += lastdec + TIMER_LOAD_VAL - now; + } + lastdec = now; + + return timestamp; +} + +void udelay_masked (unsigned long usec) +{ +#ifdef CONFIG_INNOVATOROMAP1610 + #define LOOPS_PER_MSEC 100 /* tuned on omap1610 */ + volatile int i, time_remaining = LOOPS_PER_MSEC*usec; + for (i=time_remaining; i>0; i--) { } +#else + + ulong tmo; + + tmo = usec / 1000; + tmo *= CFG_HZ; + tmo /= 1000; + + reset_timer_masked (); + + while (get_timer_masked () < tmo) + /*NOP*/; +#endif +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk (void) +{ + ulong tbclk; + tbclk = CFG_HZ; + return tbclk; +} diff --git a/cpu/arm926ejs/start.S b/cpu/arm926ejs/start.S new file mode 100644 index 0000000..08b2bbc --- /dev/null +++ b/cpu/arm926ejs/start.S @@ -0,0 +1,426 @@ +/* + * armboot - Startup Code for ARM926EJS CPU-core + * + * Copyright (c) 2003 Texas Instruments + * + * ----- Adapted for OMAP1610 from ARM925t code ------ + * + * 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> + +#if defined(CONFIG_OMAP1610) +#include <./configs/omap1510.h> +#endif + +/* + ************************************************************************* + * + * Jump vector table as in table 3.1 in [1] + * + ************************************************************************* + */ + + +.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 + + .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 + * + ************************************************************************* + */ + +/* + * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h) + */ +_TEXT_BASE: + .word TEXT_BASE + +.globl _armboot_start +_armboot_start: + .word _start + +/* + * Note: _armboot_end_data and _armboot_end are defined + * by the (board-dependent) linker script. + * _armboot_end_data is the first usable FLASH address after armboot + */ +.globl _armboot_end_data +_armboot_end_data: + .word armboot_end_data +.globl _armboot_end +_armboot_end: + .word armboot_end + +/* + * _armboot_real_end is the first usable RAM address behind armboot + * and the various stacks + */ +.globl _armboot_real_end +_armboot_real_end: + .word 0x0badc0de + +#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 + + + /* + * turn off the watchdog, unlock/diable sequence + */ + mov r1, #0xF5 + ldr r0, =WDTIM_MODE + strh r1, [r0] + mov r1, #0xA0 + strh r1, [r0] + + + + + + /* + * mask all IRQs by setting all bits in the INTMR - default + */ + + mov r1, #0xffffffff + ldr r0, =REG_IHL1_MIR + str r1, [r0] + ldr r0, =REG_IHL2_MIR + str r1, [r0] + bl cpu_init_crit + +relocate: + /* + * relocate armboot to RAM + */ + adr r0, _start /* r0 <- current position of code */ + ldr r2, _armboot_start + ldr r3, _armboot_end + sub r2, r3, r2 /* r2 <- size of armboot */ + ldr r1, _TEXT_BASE /* r1 <- destination address */ + add r2, r0, r2 /* r2 <- source end address */ + + /* + * r0 = source address + * r1 = target address + * r2 = source end address + */ +copy_loop: + ldmia r0!, {r3-r10} + stmia r1!, {r3-r10} + cmp r0, r2 + ble copy_loop + + /* set up the stack */ + ldr r0, _armboot_end + add r0, r0, #CONFIG_STACKSIZE + sub sp, r0, #12 /* leave 3 words for abort-stack */ + + 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 */ + orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */ + mcr p15, 0, r0, c1, c0, 0 + + /* + * Go setup Memory and board specific bits prior to relocation. + */ + mov ip, lr /* perserve 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 + @ 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, _armboot_end @ find top of stack + add r2, r2, #CONFIG_STACKSIZE @ find base of normal stack + sub r2, r2, #8 @ set base 2 words into abort stack + @ 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 + @ get bottom of stack (into sp by by user stack pointer). + ldr r13, _armboot_end + @ head to reserved words at the top of the stack + add r13, r13, #CONFIG_STACKSIZE + sub r13, r13, #8 @ reserved a couple spots in 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_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 + + .align 5 +.globl reset_cpu +reset_cpu: + ldr r1, rstctl1 /* get clkm1 reset ctl */ + mov r3, #0x0 + strh r3, [r1] /* clear it */ + mov r3, #0x8 + strh r3, [r1] /* force dsp+arm reset */ +_loop_forever: + b _loop_forever + + +rstctl1: + .word 0xfffece10 |