/* * cpu.c - A few helper functions for ARM * * Copyright (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix * * 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 version 2 * as published by the Free Software Foundation. * * 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. */ /** * @file * @brief A few helper functions for ARM */ #include <common.h> #include <init.h> #include <command.h> #include <cache.h> #include <asm/mmu.h> #include <asm/system.h> #include <asm/memory.h> /** * Enable processor's instruction cache */ void icache_enable(void) { u32 r; r = get_cr(); r |= CR_I; set_cr(r); } /** * Disable processor's instruction cache */ void icache_disable(void) { u32 r; r = get_cr(); r &= ~CR_I; set_cr(r); } /** * Detect processor's current instruction cache status * @return 0=disabled, 1=enabled */ int icache_status(void) { return (get_cr () & CR_I) != 0; } /** * Disable MMU and D-cache, flush caches * @return 0 (always) * * This function is called by shutdown_barebox to get a clean * memory/cache state. */ void arch_shutdown(void) { #ifdef CONFIG_MMU /* nearly the same as below, but this could also disable * second level cache. */ mmu_disable(); #else asm volatile ( "bl __mmu_cache_flush;" "bl __mmu_cache_off;" : : : "r0", "r1", "r2", "r3", "r6", "r10", "r12", "lr", "cc", "memory" ); #endif } #ifdef CONFIG_THUMB2_BAREBOX static void thumb2_execute(void *func, int argc, char *argv[]) { /* * Switch back to arm mode before executing external * programs. */ __asm__ __volatile__ ( "mov r0, #0\n" "mov r1, %0\n" "mov r2, %1\n" "bx %2\n" : : "r" (argc - 1), "r" (&argv[1]), "r" (func) : "r0", "r1", "r2" ); } static int execute_init(void) { do_execute = thumb2_execute; return 0; } postcore_initcall(execute_init); #endif