mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-06-09 23:36:03 +09:00
71059736b8
In U-Boot the exception vector base will be moved to top of memory, to be used to display register dump when exception occurs. But some old linux kernel does not honor the base set in CP0_EBASE. A modified exception vector base will cause kernel crash. This patch adds an option to enable reset exception vector base to its previous value, or a user configured value before booting linux kernel. Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com> Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
128 lines
3.0 KiB
C
128 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
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* Copyright (C) 1995, 1996 Paul M. Antoine
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* Copyright (C) 1998 Ulf Carlsson
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* Copyright (C) 1999 Silicon Graphics, Inc.
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* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
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* Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
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* Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
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* Copyright (C) 2014, Imagination Technologies Ltd.
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*/
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#include <common.h>
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#include <cpu_func.h>
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#include <hang.h>
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#include <init.h>
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#include <asm/mipsregs.h>
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#include <asm/addrspace.h>
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#include <asm/system.h>
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DECLARE_GLOBAL_DATA_PTR;
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static unsigned long saved_ebase;
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static void show_regs(const struct pt_regs *regs)
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{
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const int field = 2 * sizeof(unsigned long);
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unsigned int cause = regs->cp0_cause;
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unsigned int exccode;
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int i;
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/*
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* Saved main processor registers
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*/
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for (i = 0; i < 32; ) {
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if ((i % 4) == 0)
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printf("$%2d :", i);
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if (i == 0)
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printf(" %0*lx", field, 0UL);
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else if (i == 26 || i == 27)
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printf(" %*s", field, "");
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else
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printf(" %0*lx", field, regs->regs[i]);
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i++;
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if ((i % 4) == 0)
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puts("\n");
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}
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printf("Hi : %0*lx\n", field, regs->hi);
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printf("Lo : %0*lx\n", field, regs->lo);
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/*
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* Saved cp0 registers
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*/
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printf("epc : %0*lx (text %0*lx)\n", field, regs->cp0_epc,
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field, regs->cp0_epc - gd->reloc_off);
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printf("ra : %0*lx (text %0*lx)\n", field, regs->regs[31],
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field, regs->regs[31] - gd->reloc_off);
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printf("Status: %08x\n", (uint32_t) regs->cp0_status);
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exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
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printf("Cause : %08x (ExcCode %02x)\n", cause, exccode);
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if (1 <= exccode && exccode <= 5)
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printf("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
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printf("PrId : %08x\n", read_c0_prid());
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}
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void do_reserved(const struct pt_regs *regs)
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{
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puts("\nOoops:\n");
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show_regs(regs);
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hang();
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}
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void do_ejtag_debug(const struct pt_regs *regs)
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{
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const int field = 2 * sizeof(unsigned long);
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unsigned long depc;
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unsigned int debug;
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depc = read_c0_depc();
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debug = read_c0_debug();
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printf("SDBBP EJTAG debug exception: c0_depc = %0*lx, DEBUG = %08x\n",
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field, depc, debug);
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}
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static void set_handler(unsigned long offset, void *addr, unsigned long size)
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{
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unsigned long ebase = gd->irq_sp;
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memcpy((void *)(ebase + offset), addr, size);
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flush_cache(ebase + offset, size);
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}
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void trap_init(ulong reloc_addr)
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{
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unsigned long ebase = gd->irq_sp;
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set_handler(0x180, &except_vec3_generic, 0x80);
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set_handler(0x280, &except_vec_ejtag_debug, 0x80);
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saved_ebase = read_c0_ebase() & 0xfffff000;
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write_c0_ebase(ebase);
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clear_c0_status(ST0_BEV);
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execution_hazard_barrier();
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}
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void trap_restore(void)
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{
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set_c0_status(ST0_BEV);
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execution_hazard_barrier();
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#ifdef CONFIG_OVERRIDE_EXCEPTION_VECTOR_BASE
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write_c0_ebase(CONFIG_NEW_EXCEPTION_VECTOR_BASE & 0xfffff000);
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#else
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write_c0_ebase(saved_ebase);
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#endif
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clear_c0_status(ST0_BEV);
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execution_hazard_barrier();
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}
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