diff options
Diffstat (limited to 'cpu/nios2')
| -rw-r--r-- | cpu/nios2/Makefile | 44 | ||||
| -rw-r--r-- | cpu/nios2/config.mk | 24 | ||||
| -rw-r--r-- | cpu/nios2/cpu.c | 62 | ||||
| -rw-r--r-- | cpu/nios2/exceptions.S | 152 | ||||
| -rw-r--r-- | cpu/nios2/interrupts.c | 229 | ||||
| -rw-r--r-- | cpu/nios2/serial.c | 144 | ||||
| -rw-r--r-- | cpu/nios2/start.S | 211 | ||||
| -rw-r--r-- | cpu/nios2/traps.c | 42 |
8 files changed, 908 insertions, 0 deletions
diff --git a/cpu/nios2/Makefile b/cpu/nios2/Makefile new file mode 100644 index 0000000..76b324a --- /dev/null +++ b/cpu/nios2/Makefile @@ -0,0 +1,44 @@ +# +# (C) Copyright 2000 +# 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 +AOBJS = exceptions.o +OBJS = cpu.o interrupts.o serial.o traps.o + +all: .depend $(START) $(LIB) + +$(LIB): $(OBJS) $(AOBJS) + $(AR) crv $@ $(OBJS) $(AOBJS) + +######################################################################### + +.depend: Makefile $(START:.o=.S) $(OBJS:.o=.c) $(AOBJS:.o=.S) + $(CC) -M $(CFLAGS) $(START:.o=.S) $(OBJS:.o=.c) $(AOBJS:.o=.S) > $@ + +sinclude .depend + +######################################################################### diff --git a/cpu/nios2/config.mk b/cpu/nios2/config.mk new file mode 100644 index 0000000..f228d72 --- /dev/null +++ b/cpu/nios2/config.mk @@ -0,0 +1,24 @@ +# +# (C) Copyright 2000 +# 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 +# + +PLATFORM_RELFLAGS += diff --git a/cpu/nios2/cpu.c b/cpu/nios2/cpu.c new file mode 100644 index 0000000..c9db127 --- /dev/null +++ b/cpu/nios2/cpu.c @@ -0,0 +1,62 @@ +/* + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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 <common.h> +#include <nios2.h> +#include <nios2-io.h> + +#if defined (CFG_NIOS_SYSID_BASE) +#include <linux/time.h> +static void check_sysid (void) +{ + struct nios_sysid_t *sysid = + (struct nios_sysid_t *)CACHE_BYPASS(CFG_NIOS_SYSID_BASE); + struct tm t; + char asc[32]; + + localtime_r ((time_t *)&sysid->timestamp, &t); + asctime_r (&t, asc); + printf ("SYSID : %08x, %s", sysid->id, asc); + +} +#endif /* CFG_NIOS_SYSID_BASE */ + +int checkcpu (void) +{ + printf ("CPU : Nios-II\n"); +#if !defined(CFG_NIOS_SYSID_BASE) + printf ("SYSID : <unknown>\n"); +#else + check_sysid (); +#endif + return (0); +} + + +int do_reset (void) +{ + void (*rst)(void) = (void(*)(void))CFG_RESET_ADDR; + disable_interrupts (); + rst(); + return(0); +} diff --git a/cpu/nios2/exceptions.S b/cpu/nios2/exceptions.S new file mode 100644 index 0000000..d3b95cf --- /dev/null +++ b/cpu/nios2/exceptions.S @@ -0,0 +1,152 @@ +/* + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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 <asm/opcodes.h> + + + .text + .align 4 + + .global _exception + +_exception: + /* SAVE ALL REGS -- this allows trap and unimplemented + * instruction handlers to be coded conveniently in C + */ + addi sp, sp, -(33*4) + stw r0, 0(sp) + stw r1, 4(sp) + stw r2, 8(sp) + stw r3, 12(sp) + stw r4, 16(sp) + stw r5, 20(sp) + stw r6, 24(sp) + stw r7, 28(sp) + stw r8, 32(sp) + stw r9, 36(sp) + stw r10, 40(sp) + stw r11, 44(sp) + stw r12, 48(sp) + stw r13, 52(sp) + stw r14, 56(sp) + stw r15, 60(sp) + stw r16, 64(sp) + stw r17, 68(sp) + stw r19, 72(sp) + stw r19, 76(sp) + stw r20, 80(sp) + stw r21, 84(sp) + stw r22, 88(sp) + stw r23, 92(sp) + stw r24, 96(sp) + stw r25, 100(sp) + stw r26, 104(sp) + stw r27, 108(sp) + stw r28, 112(sp) + stw r29, 116(sp) + stw r30, 120(sp) + stw r31, 124(sp) + rdctl et, estatus + stw et, 128(sp) + + /* If interrupts are disabled -- software interrupt */ + rdctl et, estatus + andi et, et, 1 + beq et, r0, 0f + + /* If no interrupts are pending -- software interrupt */ + rdctl et, ipending + beq et, r0, 0f + + /* HARDWARE INTERRUPT: Call interrupt handler */ + movhi r3, %hi(external_interrupt) + ori r3, r3, %lo(external_interrupt) + mov r4, sp /* ptr to regs */ + callr r3 + + /* Return address fixup: execution resumes by re-issue of + * interrupted instruction at ea-4 (ea == r29). Here we do + * simple fixup to allow common exception return. + */ + ldw r3, 116(sp) + addi r3, r3, -4 + stw r3, 116(sp) + br _exception_return + +0: + /* TRAP EXCEPTION */ + movhi r3, %hi(OPC_TRAP) + ori r3, r3, %lo(OPC_TRAP) + addi r1, ea, -4 + ldw r1, 0(r1) + bne r1, r3, 1f + movhi r3, %hi(trap_handler) + ori r3, r3, %lo(trap_handler) + mov r4, sp /* ptr to regs */ + callr r3 + br _exception_return + +1: + /* UNIMPLEMENTED INSTRUCTION EXCEPTION */ + movhi r3, %hi(soft_emulation) + ori r3, r3, %lo(soft_emulation) + mov r4, sp /* ptr to regs */ + callr r3 + + /* Restore regsisters and return from exception*/ +_exception_return: + ldw r1, 4(sp) + ldw r2, 8(sp) + ldw r3, 12(sp) + ldw r4, 16(sp) + ldw r5, 20(sp) + ldw r6, 24(sp) + ldw r7, 28(sp) + ldw r8, 32(sp) + ldw r9, 36(sp) + ldw r10, 40(sp) + ldw r11, 44(sp) + ldw r12, 48(sp) + ldw r13, 52(sp) + ldw r14, 56(sp) + ldw r15, 60(sp) + ldw r16, 64(sp) + ldw r17, 68(sp) + ldw r19, 72(sp) + ldw r19, 76(sp) + ldw r20, 80(sp) + ldw r21, 84(sp) + ldw r22, 88(sp) + ldw r23, 92(sp) + ldw r24, 96(sp) + ldw r25, 100(sp) + ldw r26, 104(sp) + ldw r27, 108(sp) + ldw r28, 112(sp) + ldw r29, 116(sp) + ldw r30, 120(sp) + ldw r31, 124(sp) + addi sp, sp, (33*4) + eret +/*-------------------------------------------------------------*/ diff --git a/cpu/nios2/interrupts.c b/cpu/nios2/interrupts.c new file mode 100644 index 0000000..4a6da58 --- /dev/null +++ b/cpu/nios2/interrupts.c @@ -0,0 +1,229 @@ +/* + * (C) Copyright 2000-2002 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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 <nios2.h> +#include <nios2-io.h> +#include <asm/ptrace.h> +#include <common.h> +#include <command.h> +#include <watchdog.h> +#ifdef CONFIG_STATUS_LED +#include <status_led.h> +#endif + +#if defined(CFG_NIOS_TMRBASE) && !defined(CFG_NIOS_TMRIRQ) +#error CFG_NIOS_TMRIRQ not defined (see documentation) +#endif + +/****************************************************************************/ + +struct irq_action { + interrupt_handler_t *handler; + void *arg; + int count; +}; + +static struct irq_action vecs[32]; + +/*************************************************************************/ +volatile ulong timestamp = 0; + +void reset_timer (void) +{ + timestamp = 0; +} + +ulong get_timer (ulong base) +{ + WATCHDOG_RESET (); + return (timestamp - base); +} + +void set_timer (ulong t) +{ + timestamp = t; +} + + +/* The board must handle this interrupt if a timer is not + * provided. + */ +#if defined(CFG_NIOS_TMRBASE) +void tmr_isr (void *arg) +{ + nios_timer_t *tmr = (nios_timer_t *)arg; + /* Interrupt is cleared by writing anything to the + * status register. + */ + tmr->status = 0; + timestamp += CFG_NIOS_TMRMS; +#ifdef CONFIG_STATUS_LED + status_led_tick(timestamp); +#endif +} + +static void tmr_init (void) +{ + nios_timer_t *tmr =(nios_timer_t *)CACHE_BYPASS(CFG_NIOS_TMRBASE); + + tmr->control &= ~(NIOS_TIMER_START | NIOS_TIMER_ITO); + tmr->control |= NIOS_TIMER_STOP; +#if defined(CFG_NIOS_TMRCNT) + tmr->periodl = CFG_NIOS_TMRCNT & 0xffff; + tmr->periodh = (CFG_NIOS_TMRCNT >> 16) & 0xffff; +#endif + tmr->control |= ( NIOS_TIMER_ITO | + NIOS_TIMER_CONT | + NIOS_TIMER_START ); + irq_install_handler (CFG_NIOS_TMRIRQ, tmr_isr, (void *)tmr); +} + +#endif /* CFG_NIOS_TMRBASE */ + +/*************************************************************************/ +int disable_interrupts (void) +{ + int val = rdctl (CTL_STATUS); + wrctl (CTL_STATUS, val & ~STATUS_IE); + return (val & STATUS_IE); +} + +void enable_interrupts( void ) +{ + int val = rdctl (CTL_STATUS); + wrctl (CTL_STATUS, val | STATUS_IE); +} + +void external_interrupt (struct pt_regs *regs) +{ + unsigned irqs; + struct irq_action *act; + + /* Evaluate only irqs that are both enabled AND pending */ + irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING); + act = vecs; + + /* Assume (as does the Nios2 HAL) that bit 0 is highest + * priority. NOTE: There is ALWAYS a handler assigned + * (the default if no other). + */ + while (irqs) { + if (irqs & 1) { + act->handler (act->arg); + act->count++; + } + irqs >>=1; + act++; + } +} + +static void def_hdlr (void *arg) +{ + unsigned irqs = rdctl (CTL_IENABLE); + + /* Disable the individual interrupt -- with gratuitous + * warning. + */ + irqs &= ~(1 << (int)arg); + wrctl (CTL_IENABLE, irqs); + printf ("WARNING: Disabling unhandled interrupt: %d\n", + (int)arg); +} + +/*************************************************************************/ +void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg) +{ + + int flag; + struct irq_action *act; + unsigned ena = rdctl (CTL_IENABLE); + + if ((irq < 0) || (irq > 31)) + return; + act = &vecs[irq]; + + flag = disable_interrupts (); + if (hdlr) { + act->handler = hdlr; + act->arg = arg; + ena |= (1 << irq); /* enable */ + } else { + act->handler = def_hdlr; + act->arg = (void *)irq; + ena &= ~(1 << irq); /* disable */ + } + wrctl (CTL_IENABLE, ena); + if (flag) enable_interrupts (); +} + + +int interrupt_init (void) +{ + int i; + + /* Assign the default handler to all */ + for (i = 0; i < 32; i++) { + vecs[i].handler = def_hdlr; + vecs[i].arg = (void *)i; + vecs[i].count = 0; + } + +#if defined(CFG_NIOS_TMRBASE) + tmr_init (); +#endif + + enable_interrupts (); + return (0); +} + + +/*************************************************************************/ +#if (CONFIG_COMMANDS & CFG_CMD_IRQ) +int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{ + int i; + struct irq_action *act = vecs; + + printf ("\nInterrupt-Information:\n\n"); + printf ("Nr Routine Arg Count\n"); + printf ("-----------------------------\n"); + + for (i=0; i<32; i++) { + if (act->handler != def_hdlr) { + printf ("%02d %08lx %08lx %d\n", + i, + (ulong)act->handler, + (ulong)act->arg, + act->count); + } + act++; + } + printf ("\n"); + + return (0); +} +#endif /* CONFIG_COMMANDS & CFG_CMD_IRQ */ diff --git a/cpu/nios2/serial.c b/cpu/nios2/serial.c new file mode 100644 index 0000000..2d08c93 --- /dev/null +++ b/cpu/nios2/serial.c @@ -0,0 +1,144 @@ +/* + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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 <common.h> +#include <watchdog.h> +#include <nios2.h> +#include <nios2-io.h> + +/*------------------------------------------------------------------ + * JTAG acts as the serial port + *-----------------------------------------------------------------*/ +#if defined(CONFIG_CONSOLE_JTAG) + +static nios_jtag_t *jtag = + (nios_jtag_t *)CACHE_BYPASS(CFG_NIOS_CONSOLE); + +void serial_setbrg( void ){ return; } +int serial_init( void ) { return(0);} + +void serial_putc (char c) +{ + unsigned val; + + while (NIOS_JTAG_WSPACE (jtag->control) == 0) + WATCHDOG_RESET (); + jtag->data = (unsigned char)c; +} + +void serial_puts (const char *s) +{ + while (*s != 0) + serial_putc (*s++); +} + +int serial_tstc (void) +{ + return (jtag->control & NIOS_JTAG_RRDY); +} + +int serial_getc (void) +{ + int c; + unsigned val; + + while (1) { + WATCHDOG_RESET (); + val = jtag->data; + if (val & NIOS_JTAG_RVALID) + break; + } + c = val & 0x0ff; + return (c); +} + +/*------------------------------------------------------------------ + * UART the serial port + *-----------------------------------------------------------------*/ +#else + +static nios_uart_t *uart = (nios_uart_t *) + CACHE_BYPASS(CFG_NIOS_CONSOLE); + +#if defined(CFG_NIOS_FIXEDBAUD) + +/* Everything's already setup for fixed-baud PTF + * assignment + */ +void serial_setbrg (void){ return; } +int serial_init (void) { return (0);} + +#else + +void serial_setbrg (void) +{ + DECLARE_GLOBAL_DATA_PTR; + unsigned div; + + div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1; + uart->divisor = div; + return; +} + +int serial_init (void) +{ + serial_setbrg (); + return (0); +} + +#endif /* CFG_NIOS_FIXEDBAUD */ + + +/*----------------------------------------------------------------------- + * UART CONSOLE + *---------------------------------------------------------------------*/ +void serial_putc (char c) +{ + if (c == '\n') + serial_putc ('\r'); + while ((uart->status & NIOS_UART_TRDY) == 0) + WATCHDOG_RESET (); + uart->txdata = (unsigned char)c; +} + +void serial_puts (const char *s) +{ + while (*s != 0) { + serial_putc (*s++); + } +} + +int serial_tstc (void) +{ + return (uart->status & NIOS_UART_RRDY); +} + +int serial_getc (void) +{ + while (serial_tstc () == 0) + WATCHDOG_RESET (); + return( uart->rxdata & 0x00ff ); +} + +#endif /* CONFIG_JTAG_CONSOLE */ diff --git a/cpu/nios2/start.S b/cpu/nios2/start.S new file mode 100644 index 0000000..281d42c --- /dev/null +++ b/cpu/nios2/start.S @@ -0,0 +1,211 @@ +/* + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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> + +/************************************************************************* + * RESTART + ************************************************************************/ + + .text + .global _start + +_start: + /* ICACHE INIT -- only the icache line at the reset address + * is invalidated at reset. So the init must stay within + * the cache line size (8 words). If GERMS is used, we'll + * just be invalidating the cache a second time. If cache + * is not implemented initi behaves as nop. + */ + movhi r4, %hi(CFG_ICACHELINE_SIZE) + ori r4, r4, %lo(CFG_ICACHELINE_SIZE) + movhi r5, %hi(CFG_ICACHE_SIZE) + ori r5, r5, %lo(CFG_ICACHE_SIZE) + mov r6, r0 +0: initi r6 + add r6, r6, r4 + bltu r6, r5, 0b + + /* INTERRUPTS -- for now, all interrupts masked and globally + * disabled. + */ + wrctl status, r0 /* Disable interrupts */ + wrctl ienable, r0 /* All disabled */ + + /* DCACHE INIT -- if dcache not implemented, initd behaves as + * nop. + */ + movhi r4, %hi(CFG_DCACHELINE_SIZE) + ori r4, r4, %lo(CFG_DCACHELINE_SIZE) + movhi r5, %hi(CFG_DCACHE_SIZE) + ori r5, r5, %lo(CFG_DCACHE_SIZE) + mov r6, r0 +1: initd 0(r6) + add r6, r6, r4 + bltu r6, r5, 1b + + /* RELOCATE CODE, DATA & COMMAND TABLE -- the following code + * assumes code, data and the command table are all + * contiguous. This lets us relocate everything as a single + * block. Make sure the linker script matches this ;-) + */ + nextpc r4 +_cur: movhi r5, %hi(_cur - _start) + ori r5, r5, %lo(_cur - _start) + sub r4, r4, r5 /* r4 <- cur _start */ + mov r8, r4 + movhi r5, %hi(_start) + ori r5, r5, %lo(_start) /* r5 <- linked _start */ + beq r4, r5, 3f + + movhi r6, %hi(_edata) + ori r6, r6, %lo(_edata) +2: ldwio r7, 0(r4) + addi r4, r4, 4 + stwio r7, 0(r5) + addi r5, r5, 4 + bne r5, r6, 2b +3: + + /* ZERO BSS/SBSS -- bss and sbss are assumed to be adjacent + * and between __bss_start and _end. + */ + movhi r5, %hi(__bss_start) + ori r5, r5, %lo(__bss_start) + movhi r6, %hi(_end) + ori r6, r6, %lo(_end) + beq r5, r6, 5f + +4: stwio r0, 0(r5) + addi r5, r5, 4 + bne r5, r6, 4b +5: + + /* GLOBAL POINTER -- the global pointer is used to reference + * "small data" (see -G switch). The linker script must + * provide the gp address. + */ + movhi gp, %hi(_gp) + ori gp, gp, %lo(_gp) + + /* JUMP TO RELOC ADDR */ + movhi r4, %hi(_reloc) + ori r4, r4, %lo(_reloc) + jmp r4 +_reloc: + + /* COPY EXCEPTION TRAMPOLINE -- copy the tramp to the + * exception address. + */ +#if !defined(CONFIG_ROM_STUBS) + movhi r4, %hi(_except_start) + ori r4, r4, %lo(_except_start) + movhi r5, %hi(_except_end) + ori r5, r5, %lo(_except_end) + movhi r6, %hi(CFG_EXCEPTION_ADDR) + ori r6, r6, %lo(CFG_EXCEPTION_ADDR) + +6: ldwio r7, 0(r4) + stwio r7, 0(r6) + addi r4, r4, 4 + addi r6, r6, 4 + bne r4, r5, 6b +#endif + + /* STACK INIT -- zero top two words for call back chain. + */ + movhi sp, %hi(CFG_INIT_SP) + ori sp, sp, %lo(CFG_INIT_SP) + addi sp, sp, -8 + stw r0, 0(sp) + stw r0, 4(sp) + mov fp, sp + + /* + * Call board_init -- never returns + */ + movhi r4, %hi(board_init@h) + ori r4, r4, %lo(board_init@h) + callr r4 + + /* NEVER RETURNS -- but branch to the _start just + * in case ;-) + */ + br _start + + /* EXCEPTION TRAMPOLINE -- the following gets copied + * to the exception address. + */ +_except_start: + movhi et, %hi(_exception) + ori et, et, %lo(_exception) + jmp et +_except_end: + + +/* + * dly_clks -- Nios2 (like Nios1) doesn't have a timebase in + * the core. For simple delay loops, we do our best by counting + * instruction cycles. + * + * Instruction performance varies based on the core. For cores + * with icache and static/dynamic branch prediction (II/f, II/s): + * + * Normal ALU (e.g. add, cmp, etc): 1 cycle + * Branch (correctly predicted, taken): 2 cycles + * Negative offset is predicted (II/s). + * + * For cores without icache and no branch prediction (II/e): + * + * Normal ALU (e.g. add, cmp, etc): 6 cycles + * Branch (no prediction): 6 cycles + * + * For simplicity, if an instruction cache is implemented we + * assume II/f or II/s. Otherwise, we use the II/e. + * + */ + .globl dly_clks + +dly_clks: + +#if (CFG_ICACHE_SIZE > 0) + subi r4, r4, 3 /* 3 clocks/loop */ +#else + subi r4, r4, 12 /* 12 clocks/loop */ +#endif + bge r4, r0, dly_clks + ret + + +#if !defined(CONFIG_IDENT_STRING) +#define CONFIG_IDENT_STRING "" +#endif + .data + .globl version_string + +version_string: + .ascii U_BOOT_VERSION + .ascii " (", __DATE__, " - ", __TIME__, ")" + .ascii CONFIG_IDENT_STRING, "\0" diff --git a/cpu/nios2/traps.c b/cpu/nios2/traps.c new file mode 100644 index 0000000..3f1517d --- /dev/null +++ b/cpu/nios2/traps.c @@ -0,0 +1,42 @@ +/* + * (C) Copyright 2004, Psyent Corporation <www.psyent.com> + * Scott McNutt <smcnutt@psyent.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 <asm/ptrace.h> +#include <common.h> + +void trap_handler (struct pt_regs *regs) +{ + /* Just issue warning */ + printf ("\n\n*** WARNING: unimplemented trap @ %08x\n\n", + regs->reg[29] - 4); +} + +void soft_emulation (struct pt_regs *regs) +{ + /* TODO: Software emulation of mul/div etc. Until this is + * implemented, generate warning and hang. + */ + printf ("\n\n*** ERROR: unimplemented instruction @ %08x\n", + regs->reg[29] - 4); + hang (); +} |