nds32: always polling after gdb attached

[openocd.git] / src / target / nds32_v3_common.c

/***************************************************************************
 *   Copyright (C) 2013 Andes Technology                                   *
 *   Hsiangkai Wang <hkwang@andestech.com>                                 *
 *                                                                         *
 *   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.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "breakpoints.h"
#include "nds32_reg.h"
#include "nds32_disassembler.h"
#include "nds32.h"
#include "nds32_aice.h"
#include "nds32_v3_common.h"

static struct breakpoint syscall_breakpoint = {
        0x80,
        0,
        4,
        BKPT_SOFT,
        0,
        NULL,
        NULL,
        0x515CA11,
        0,
};

static struct nds32_v3_common_callback *v3_common_callback;

static int nds32_v3_register_mapping(struct nds32 *nds32, int reg_no)
{
        if (reg_no == PC)
                return IR11;

        return reg_no;
}

static int nds32_v3_get_debug_reason(struct nds32 *nds32, uint32_t *reason)
{
        uint32_t edmsw;
        struct aice_port_s *aice = target_to_aice(nds32->target);
        aice_read_debug_reg(aice, NDS_EDM_SR_EDMSW, &edmsw);

        *reason = (edmsw >> 12) & 0x0F;

        return ERROR_OK;
}

/**
 * Save processor state.  This is called after a HALT instruction
 * succeeds, and on other occasions the processor enters debug mode
 * (breakpoint, watchpoint, etc).
 */
static int nds32_v3_debug_entry(struct nds32 *nds32, bool enable_watchpoint)
{
        LOG_DEBUG("nds32_v3_debug_entry");

        enum target_state backup_state = nds32->target->state;
        nds32->target->state = TARGET_HALTED;

        if (nds32->init_arch_info_after_halted == false) {
                /* init architecture info according to config registers */
                CHECK_RETVAL(nds32_config(nds32));

                nds32->init_arch_info_after_halted = true;
        }

        /* REVISIT entire cache should already be invalid !!! */
        register_cache_invalidate(nds32->core_cache);

        /* deactivate all hardware breakpoints */
        CHECK_RETVAL(v3_common_callback->deactivate_hardware_breakpoint(nds32->target));

        if (enable_watchpoint)
                CHECK_RETVAL(v3_common_callback->deactivate_hardware_watchpoint(nds32->target));

        if (nds32->virtual_hosting) {
                if (syscall_breakpoint.set) {
                        /** disable virtual hosting */

                        /* remove breakpoint at syscall entry */
                        target_remove_breakpoint(nds32->target, &syscall_breakpoint);
                        syscall_breakpoint.set = 0;

                        uint32_t value_pc;
                        nds32_get_mapped_reg(nds32, PC, &value_pc);
                        if (value_pc == syscall_breakpoint.address)
                                /** process syscall for virtual hosting */
                                nds32->hit_syscall = true;
                }
        }

        if (ERROR_OK != nds32_examine_debug_reason(nds32)) {
                nds32->target->state = backup_state;

                /* re-activate all hardware breakpoints & watchpoints */
                CHECK_RETVAL(v3_common_callback->activate_hardware_breakpoint(nds32->target));

                if (enable_watchpoint)
                        CHECK_RETVAL(v3_common_callback->activate_hardware_watchpoint(nds32->target));

                return ERROR_FAIL;
        }

        /* Save registers. */
        nds32_full_context(nds32);

        /* check interrupt level */
        v3_common_callback->check_interrupt_stack(nds32);

        return ERROR_OK;
}

/**
 * Restore processor state.
 */
static int nds32_v3_leave_debug_state(struct nds32 *nds32, bool enable_watchpoint)
{
        LOG_DEBUG("nds32_v3_leave_debug_state");

        struct target *target = nds32->target;

        /* activate all hardware breakpoints */
        CHECK_RETVAL(v3_common_callback->activate_hardware_breakpoint(target));

        if (enable_watchpoint) {
                /* activate all watchpoints */
                CHECK_RETVAL(v3_common_callback->activate_hardware_watchpoint(target));
        }

        /* restore interrupt stack */
        v3_common_callback->restore_interrupt_stack(nds32);

        /* REVISIT once we start caring about MMU and cache state,
         * address it here ...
         */

        /* restore PSW, PC, and R0 ... after flushing any modified
         * registers.
         */
        CHECK_RETVAL(nds32_restore_context(target));

        if (nds32->virtual_hosting) {
                /** enable virtual hosting */
                uint32_t value_ir3;
                uint32_t entry_size;
                uint32_t syscall_address;

                /* get syscall entry address */
                nds32_get_mapped_reg(nds32, IR3, &value_ir3);
                entry_size = 0x4 << (((value_ir3 >> 14) & 0x3) << 1);
                syscall_address = (value_ir3 & 0xFFFF0000) + entry_size * 8; /* The index of SYSCALL is 8 */

                if (nds32->hit_syscall) {
                        /* single step to skip syscall entry */
                        /* use IRET to skip syscall */
                        struct aice_port_s *aice = target_to_aice(target);
                        uint32_t value_ir9;
                        uint32_t value_ir6;
                        uint32_t syscall_id;

                        nds32_get_mapped_reg(nds32, IR6, &value_ir6);
                        syscall_id = (value_ir6 >> 16) & 0x7FFF;

                        if (syscall_id == NDS32_SYSCALL_EXIT) {
                                /* If target hits exit syscall, do not use IRET to skip handler. */
                                aice_step(aice);
                        } else {
                                /* use api->read/write_reg to skip nds32 register cache */
                                uint32_t value_dimbr;
                                aice_read_debug_reg(aice, NDS_EDM_SR_DIMBR, &value_dimbr);
                                aice_write_register(aice, IR11, value_dimbr + 0xC);

                                aice_read_register(aice, IR9, &value_ir9);
                                value_ir9 += 4; /* syscall is always 4 bytes */
                                aice_write_register(aice, IR9, value_ir9);

                                /* backup hardware breakpoint 0 */
                                uint32_t backup_bpa, backup_bpam, backup_bpc;
                                aice_read_debug_reg(aice, NDS_EDM_SR_BPA0, &backup_bpa);
                                aice_read_debug_reg(aice, NDS_EDM_SR_BPAM0, &backup_bpam);
                                aice_read_debug_reg(aice, NDS_EDM_SR_BPC0, &backup_bpc);

                                /* use hardware breakpoint 0 to stop cpu after skipping syscall */
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPA0, value_ir9);
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPAM0, 0);
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPC0, 0xA);

                                /* Execute two IRET.
                                 * First IRET is used to quit debug mode.
                                 * Second IRET is used to quit current syscall. */
                                uint32_t dim_inst[4] = {NOP, NOP, IRET, IRET};
                                aice_execute(aice, dim_inst, 4);

                                /* restore origin hardware breakpoint 0 */
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPA0, backup_bpa);
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPAM0, backup_bpam);
                                aice_write_debug_reg(aice, NDS_EDM_SR_BPC0, backup_bpc);
                        }

                        nds32->hit_syscall = false;
                }

                /* insert breakpoint at syscall entry */
                syscall_breakpoint.address = syscall_address;
                syscall_breakpoint.type = BKPT_SOFT;
                syscall_breakpoint.set = 1;
                target_add_breakpoint(target, &syscall_breakpoint);
        }

        return ERROR_OK;
}

static int nds32_v3_get_exception_address(struct nds32 *nds32,
                uint32_t *address, uint32_t reason)
{
        LOG_DEBUG("nds32_v3_get_exception_address");

        struct aice_port_s *aice = target_to_aice(nds32->target);
        struct target *target = nds32->target;
        uint32_t edmsw;
        uint32_t edm_cfg;
        uint32_t match_bits;
        uint32_t match_count;
        int32_t i;
        static int32_t number_of_hard_break;

        if (number_of_hard_break == 0) {
                aice_read_debug_reg(aice, NDS_EDM_SR_EDM_CFG, &edm_cfg);
                number_of_hard_break = (edm_cfg & 0x7) + 1;
        }

        aice_read_debug_reg(aice, NDS_EDM_SR_EDMSW, &edmsw);
        /* clear matching bits (write-one-clear) */
        aice_write_debug_reg(aice, NDS_EDM_SR_EDMSW, edmsw);
        match_bits = (edmsw >> 4) & 0xFF;
        match_count = 0;
        for (i = 0 ; i < number_of_hard_break ; i++) {
                if (match_bits & (1 << i)) {
                        aice_read_debug_reg(aice, NDS_EDM_SR_BPA0 + i, address);
                        match_count++;
                }
        }

        if (match_count > 1) { /* multiple hits */
                *address = 0;
                return ERROR_OK;
        } else if (match_count == 1) {
                uint32_t val_pc;
                uint32_t opcode;
                struct nds32_instruction instruction;
                struct watchpoint *wp;
                bool hit;

                nds32_get_mapped_reg(nds32, PC, &val_pc);

                if ((NDS32_DEBUG_DATA_ADDR_WATCHPOINT_NEXT_PRECISE == reason) ||
                                (NDS32_DEBUG_DATA_VALUE_WATCHPOINT_NEXT_PRECISE == reason)) {
                        if (edmsw & 0x4) /* check EDMSW.IS_16BIT */
                                val_pc -= 2;
                        else
                                val_pc -= 4;
                }

                nds32_read_opcode(nds32, val_pc, &opcode);
                nds32_evaluate_opcode(nds32, opcode, val_pc, &instruction);

                LOG_DEBUG("PC: 0x%08x, access start: 0x%08x, end: 0x%08x", val_pc,
                                instruction.access_start, instruction.access_end);

                /* check if multiple hits in the access range */
                uint32_t in_range_watch_count = 0;
                for (wp = target->watchpoints; wp; wp = wp->next) {
                        if ((instruction.access_start <= wp->address) &&
                                        (wp->address < instruction.access_end))
                                in_range_watch_count++;
                }
                if (in_range_watch_count > 1) {
                        /* Hit LSMW instruction. */
                        *address = 0;
                        return ERROR_OK;
                }

                /* dispel false match */
                hit = false;
                for (wp = target->watchpoints; wp; wp = wp->next) {
                        if (((*address ^ wp->address) & (~wp->mask)) == 0) {
                                uint32_t watch_start;
                                uint32_t watch_end;

                                watch_start = wp->address;
                                watch_end = wp->address + wp->length;

                                if ((watch_end <= instruction.access_start) ||
                                                (instruction.access_end <= watch_start))
                                        continue;

                                hit = true;
                                break;
                        }
                }

                if (hit)
                        return ERROR_OK;
                else
                        return ERROR_FAIL;
        } else if (match_count == 0) {
                /* global stop is precise exception */
                if ((NDS32_DEBUG_LOAD_STORE_GLOBAL_STOP == reason) && nds32->global_stop) {
                        /* parse instruction to get correct access address */
                        uint32_t val_pc;
                        uint32_t opcode;
                        struct nds32_instruction instruction;

                        nds32_get_mapped_reg(nds32, PC, &val_pc);
                        nds32_read_opcode(nds32, val_pc, &opcode);
                        nds32_evaluate_opcode(nds32, opcode, val_pc, &instruction);

                        *address = instruction.access_start;

                        return ERROR_OK;
                }
        }

        *address = 0xFFFFFFFF;
        return ERROR_FAIL;
}

void nds32_v3_common_register_callback(struct nds32_v3_common_callback *callback)
{
        v3_common_callback = callback;
}

/** target_type functions: */
/* target request support */
int nds32_v3_target_request_data(struct target *target,
                uint32_t size, uint8_t *buffer)
{
        /* AndesCore could use DTR register to communicate with OpenOCD
         * to output messages
         * Target data will be put in buffer
         * The format of DTR is as follow
         * DTR[31:16] => length, DTR[15:8] => size, DTR[7:0] => target_req_cmd
         * target_req_cmd has three possible values:
         *   TARGET_REQ_TRACEMSG
         *   TARGET_REQ_DEBUGMSG
         *   TARGET_REQ_DEBUGCHAR
         * if size == 0, target will call target_asciimsg(),
         * else call target_hexmsg()
         */
        LOG_WARNING("Not implemented: %s", __func__);

        return ERROR_OK;
}

int nds32_v3_soft_reset_halt(struct target *target)
{
        struct aice_port_s *aice = target_to_aice(target);
        return aice_assert_srst(aice, AICE_RESET_HOLD);
}

int nds32_v3_checksum_memory(struct target *target,
                uint32_t address, uint32_t count, uint32_t *checksum)
{
        LOG_WARNING("Not implemented: %s", __func__);

        return ERROR_FAIL;
}

/**
 * find out which watchpoint hits
 * get exception address and compare the address to watchpoints
 */
int nds32_v3_hit_watchpoint(struct target *target,
                struct watchpoint **hit_watchpoint)
{
        static struct watchpoint scan_all_watchpoint;

        uint32_t exception_address;
        struct watchpoint *wp;
        struct nds32 *nds32 = target_to_nds32(target);

        exception_address = nds32->watched_address;

        if (exception_address == 0xFFFFFFFF)
                return ERROR_FAIL;

        if (exception_address == 0) {
                scan_all_watchpoint.address = 0;
                scan_all_watchpoint.rw = WPT_WRITE;
                scan_all_watchpoint.next = 0;
                scan_all_watchpoint.unique_id = 0x5CA8;

                *hit_watchpoint = &scan_all_watchpoint;
                return ERROR_OK;
        }

        for (wp = target->watchpoints; wp; wp = wp->next) {
                if (((exception_address ^ wp->address) & (~wp->mask)) == 0) {
                        *hit_watchpoint = wp;

                        return ERROR_OK;
                }
        }

        return ERROR_FAIL;
}

int nds32_v3_target_create_common(struct target *target, struct nds32 *nds32)
{
        nds32->register_map = nds32_v3_register_mapping;
        nds32->get_debug_reason = nds32_v3_get_debug_reason;
        nds32->enter_debug_state = nds32_v3_debug_entry;
        nds32->leave_debug_state = nds32_v3_leave_debug_state;
        nds32->get_watched_address = nds32_v3_get_exception_address;

        /* Init target->arch_info in nds32_init_arch_info().
         * After this, user could use target_to_nds32() to get nds32 object */
        nds32_init_arch_info(target, nds32);

        return ERROR_OK;
}

int nds32_v3_run_algorithm(struct target *target,
                int num_mem_params,
                struct mem_param *mem_params,
                int num_reg_params,
                struct reg_param *reg_params,
                uint32_t entry_point,
                uint32_t exit_point,
                int timeout_ms,
                void *arch_info)
{
        LOG_WARNING("Not implemented: %s", __func__);

        return ERROR_FAIL;
}

int nds32_v3_read_buffer(struct target *target, uint32_t address,
                uint32_t size, uint8_t *buffer)
{
        struct nds32 *nds32 = target_to_nds32(target);
        struct nds32_memory *memory = &(nds32->memory);

        if ((NDS_MEMORY_ACC_CPU == memory->access_channel) &&
                        (target->state != TARGET_HALTED)) {
                LOG_WARNING("target was not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        uint32_t physical_address;
        /* BUG: If access range crosses multiple pages, the translation will not correct
         * for second page or so. */

        /* When DEX is set to one, hardware will enforce the following behavior without
         * modifying the corresponding control bits in PSW.
         *
         * Disable all interrupts
         * Become superuser mode
         * Turn off IT/DT
         * Use MMU_CFG.DE as the data access endian
         * Use MMU_CFG.DRDE as the device register access endian if MMU_CTL.DREE is asserted
         * Disable audio special features
         * Disable inline function call
         *
         * Because hardware will turn off IT/DT by default, it MUST translate virtual address
         * to physical address.
         */
        if (ERROR_OK == target->type->virt2phys(target, address, &physical_address))
                address = physical_address;
        else
                return ERROR_FAIL;

        int result;
        struct aice_port_s *aice = target_to_aice(target);
        /* give arbitrary initial value to avoid warning messages */
        enum nds_memory_access origin_access_channel = NDS_MEMORY_ACC_CPU;

        if (nds32->hit_syscall) {
                /* Use bus mode to access memory during virtual hosting */
                origin_access_channel = memory->access_channel;
                memory->access_channel = NDS_MEMORY_ACC_BUS;
                aice_memory_access(aice, NDS_MEMORY_ACC_BUS);
        }

        result = nds32_read_buffer(target, address, size, buffer);

        if (nds32->hit_syscall) {
                /* Restore access_channel after virtual hosting */
                memory->access_channel = origin_access_channel;
                aice_memory_access(aice, origin_access_channel);
        }

        return result;
}

int nds32_v3_write_buffer(struct target *target, uint32_t address,
                uint32_t size, const uint8_t *buffer)
{
        struct nds32 *nds32 = target_to_nds32(target);
        struct nds32_memory *memory = &(nds32->memory);

        if ((NDS_MEMORY_ACC_CPU == memory->access_channel) &&
                        (target->state != TARGET_HALTED)) {
                LOG_WARNING("target was not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        uint32_t physical_address;
        /* BUG: If access range crosses multiple pages, the translation will not correct
         * for second page or so. */

        /* When DEX is set to one, hardware will enforce the following behavior without
         * modifying the corresponding control bits in PSW.
         *
         * Disable all interrupts
         * Become superuser mode
         * Turn off IT/DT
         * Use MMU_CFG.DE as the data access endian
         * Use MMU_CFG.DRDE as the device register access endian if MMU_CTL.DREE is asserted
         * Disable audio special features
         * Disable inline function call
         *
         * Because hardware will turn off IT/DT by default, it MUST translate virtual address
         * to physical address.
         */
        if (ERROR_OK == target->type->virt2phys(target, address, &physical_address))
                address = physical_address;
        else
                return ERROR_FAIL;

        if (nds32->hit_syscall) {
                /* Use bus mode to access memory during virtual hosting */
                struct aice_port_s *aice = target_to_aice(target);
                enum nds_memory_access origin_access_channel;
                int result;

                origin_access_channel = memory->access_channel;
                memory->access_channel = NDS_MEMORY_ACC_BUS;
                aice_memory_access(aice, NDS_MEMORY_ACC_BUS);

                result = nds32_gdb_fileio_write_memory(nds32, address, size, buffer);

                memory->access_channel = origin_access_channel;
                aice_memory_access(aice, origin_access_channel);

                return result;
        }

        return nds32_write_buffer(target, address, size, buffer);
}

int nds32_v3_read_memory(struct target *target, uint32_t address,
                uint32_t size, uint32_t count, uint8_t *buffer)
{
        struct nds32 *nds32 = target_to_nds32(target);
        struct nds32_memory *memory = &(nds32->memory);

        if ((NDS_MEMORY_ACC_CPU == memory->access_channel) &&
                        (target->state != TARGET_HALTED)) {
                LOG_WARNING("target was not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        uint32_t physical_address;
        /* BUG: If access range crosses multiple pages, the translation will not correct
         * for second page or so. */

        /* When DEX is set to one, hardware will enforce the following behavior without
         * modifying the corresponding control bits in PSW.
         *
         * Disable all interrupts
         * Become superuser mode
         * Turn off IT/DT
         * Use MMU_CFG.DE as the data access endian
         * Use MMU_CFG.DRDE as the device register access endian if MMU_CTL.DREE is asserted
         * Disable audio special features
         * Disable inline function call
         *
         * Because hardware will turn off IT/DT by default, it MUST translate virtual address
         * to physical address.
         */
        if (ERROR_OK == target->type->virt2phys(target, address, &physical_address))
                address = physical_address;
        else
                return ERROR_FAIL;

        struct aice_port_s *aice = target_to_aice(target);
        /* give arbitrary initial value to avoid warning messages */
        enum nds_memory_access origin_access_channel = NDS_MEMORY_ACC_CPU;
        int result;

        if (nds32->hit_syscall) {
                /* Use bus mode to access memory during virtual hosting */
                origin_access_channel = memory->access_channel;
                memory->access_channel = NDS_MEMORY_ACC_BUS;
                aice_memory_access(aice, NDS_MEMORY_ACC_BUS);
        }

        result = nds32_read_memory(target, address, size, count, buffer);

        if (nds32->hit_syscall) {
                /* Restore access_channel after virtual hosting */
                memory->access_channel = origin_access_channel;
                aice_memory_access(aice, origin_access_channel);
        }

        return result;
}

int nds32_v3_write_memory(struct target *target, uint32_t address,
                uint32_t size, uint32_t count, const uint8_t *buffer)
{
        struct nds32 *nds32 = target_to_nds32(target);
        struct nds32_memory *memory = &(nds32->memory);

        if ((NDS_MEMORY_ACC_CPU == memory->access_channel) &&
                        (target->state != TARGET_HALTED)) {
                LOG_WARNING("target was not halted");
                return ERROR_TARGET_NOT_HALTED;
        }

        uint32_t physical_address;
        /* BUG: If access range crosses multiple pages, the translation will not correct
         * for second page or so. */

        /* When DEX is set to one, hardware will enforce the following behavior without
         * modifying the corresponding control bits in PSW.
         *
         * Disable all interrupts
         * Become superuser mode
         * Turn off IT/DT
         * Use MMU_CFG.DE as the data access endian
         * Use MMU_CFG.DRDE as the device register access endian if MMU_CTL.DREE is asserted
         * Disable audio special features
         * Disable inline function call
         *
         * Because hardware will turn off IT/DT by default, it MUST translate virtual address
         * to physical address.
         */
        if (ERROR_OK == target->type->virt2phys(target, address, &physical_address))
                address = physical_address;
        else
                return ERROR_FAIL;

        return nds32_write_memory(target, address, size, count, buffer);
}

int nds32_v3_init_target(struct command_context *cmd_ctx,
                struct target *target)
{
        /* Initialize anything we can set up without talking to the target */
        struct nds32 *nds32 = target_to_nds32(target);

        nds32_init(nds32);

        target->fileio_info = malloc(sizeof(struct gdb_fileio_info));
        target->fileio_info->identifier = NULL;

        return ERROR_OK;
}