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Diffstat (limited to 'cpu/arm1176/cpu.c')
| -rw-r--r-- | cpu/arm1176/cpu.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/cpu/arm1176/cpu.c b/cpu/arm1176/cpu.c new file mode 100644 index 0000000..1e94f7d --- /dev/null +++ b/cpu/arm1176/cpu.c @@ -0,0 +1,188 @@ +/* + * (C) Copyright 2004 Texas Insturments + * + * (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 <s3c6400.h> + +static void cache_flush (void); + +/* 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"); + return value; +} + +/* write to co-processor 15, register #1 (control register) */ +static void write_p15_c1 (unsigned long value) +{ + __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++) + __asm__ __volatile__("nop\n"); +} + +/* 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 */ +#define RESERVED_1 (0xf << 3) /* must be 111b for R/W */ + +int cpu_init (void) +{ + 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 ... + */ + + disable_interrupts (); + + /* turn off I/D-cache */ + icache_disable(); + dcache_disable(); + cache_flush(); + + return 0; +} + + +/* * reset the cpu by setting up the watchdog timer and let him time out */ +void reset_cpu (ulong ignored) +{ + printf("reset... \n\n\n"); + SW_RST_REG = 0x6400; + /* loop forever and wait for reset to happen */ + while (1) { + if (serial_tstc()) { + serial_getc(); + break; + } + } + /*NOTREACHED*/ +} + +int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) +{ + 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; +} + +/* It makes no sense to use the dcache if the MMU is not enabled */ +void dcache_enable (void) +{ + ulong reg; + + reg = read_p15_c1 (); + cp_delay (); + write_p15_c1 (reg | C1_DC); +} + +void dcache_disable (void) +{ + ulong reg; + + reg = read_p15_c1 (); + cp_delay (); + write_p15_c1 (reg & ~C1_DC); +} + +int dcache_status (void) +{ + return (read_p15_c1 () & C1_DC) != 0; +} + +/* flush I/D-cache */ +static void cache_flush (void) +{ + /* invalidate both caches and flush btb */ + asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (0)); + /* mem barrier to sync things */ + asm ("mcr p15, 0, %0, c7, c10, 4": :"r" (0)); +} |