/* * Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se> * * (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 <common.h> /* * The exception table consists of pairs of addresses: the first is the * address of an instruction that is allowed to fault, and the second is * the address at which the program should continue. No registers are * modified, so it is entirely up to the continuation code to figure out * what to do. * * All the routines below use bits of fixup code that are out of line * with the main instruction path. This means when everything is well, * we don't even have to jump over them. Further, they do not intrude * on our cache or tlb entries. */ DECLARE_GLOBAL_DATA_PTR; struct exception_table_entry { unsigned long insn, fixup; }; extern const struct exception_table_entry __start___ex_table[]; extern const struct exception_table_entry __stop___ex_table[]; static inline unsigned long search_one_table(const struct exception_table_entry *first, const struct exception_table_entry *last, unsigned long value) { long diff; if ((ulong) first > CONFIG_SYS_MONITOR_BASE) { /* exception occurs in FLASH, before u-boot relocation. * No relocation offset is needed. */ while (first <= last) { diff = first->insn - value; if (diff == 0) return first->fixup; first++; } } else { /* exception occurs in RAM, after u-boot relocation. * A relocation offset should be added. */ while (first <= last) { diff = (first->insn + gd->reloc_off) - value; if (diff == 0) return (first->fixup + gd->reloc_off); first++; } } return 0; } int ex_tab_message = 1; unsigned long search_exception_table(unsigned long addr) { unsigned long ret; /* There is only the kernel to search. */ ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr); /* if the serial port does not hang in exception, printf can be used */ #if !defined(CONFIG_SYS_SERIAL_HANG_IN_EXCEPTION) if (ex_tab_message) debug("Bus Fault @ 0x%08lx, fixup 0x%08lx\n", addr, ret); #endif if (ret) return ret; return 0; }