| /* |
| * (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 stacks if necessary |
| */ |
| #ifdef CONFIG_USE_IRQ |
| DECLARE_GLOBAL_DATA_PTR; |
| |
| IRQ_STACK_START = _armboot_start - CFG_MALLOC_LEN - CFG_GBL_DATA_SIZE - 4; |
| FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ; |
| #endif |
| 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; |
| } |