#include "target_type.h"
#include "register.h"
-/* cli handling */
-
-/* forward declarations */
-int mips_m4k_poll(struct target *target);
-int mips_m4k_halt(struct target *target);
-int mips_m4k_soft_reset_halt(struct target *target);
-int mips_m4k_resume(struct target *target, int current, uint32_t address, int handle_breakpoints, int debug_execution);
-int mips_m4k_step(struct target *target, int current, uint32_t address, int handle_breakpoints);
-int mips_m4k_read_memory(struct target *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer);
-int mips_m4k_write_memory(struct target *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer);
-int mips_m4k_init_target(struct command_context *cmd_ctx, struct target *target);
-int mips_m4k_target_create(struct target *target, Jim_Interp *interp);
-
-int mips_m4k_examine(struct target *target);
-int mips_m4k_assert_reset(struct target *target);
-int mips_m4k_deassert_reset(struct target *target);
-int mips_m4k_checksum_memory(struct target *target, uint32_t address, uint32_t size, uint32_t *checksum);
-
-struct target_type mips_m4k_target =
-{
- .name = "mips_m4k",
-
- .poll = mips_m4k_poll,
- .arch_state = mips32_arch_state,
-
- .target_request_data = NULL,
-
- .halt = mips_m4k_halt,
- .resume = mips_m4k_resume,
- .step = mips_m4k_step,
-
- .assert_reset = mips_m4k_assert_reset,
- .deassert_reset = mips_m4k_deassert_reset,
- .soft_reset_halt = mips_m4k_soft_reset_halt,
-
- .get_gdb_reg_list = mips32_get_gdb_reg_list,
-
- .read_memory = mips_m4k_read_memory,
- .write_memory = mips_m4k_write_memory,
- .bulk_write_memory = mips_m4k_bulk_write_memory,
- .checksum_memory = mips_m4k_checksum_memory,
- .blank_check_memory = NULL,
-
- .run_algorithm = mips32_run_algorithm,
-
- .add_breakpoint = mips_m4k_add_breakpoint,
- .remove_breakpoint = mips_m4k_remove_breakpoint,
- .add_watchpoint = mips_m4k_add_watchpoint,
- .remove_watchpoint = mips_m4k_remove_watchpoint,
-
- .target_create = mips_m4k_target_create,
- .init_target = mips_m4k_init_target,
- .examine = mips_m4k_examine,
-};
-
-int mips_m4k_examine_debug_reason(struct target *target)
+static void mips_m4k_enable_breakpoints(struct target *target);
+static void mips_m4k_enable_watchpoints(struct target *target);
+static int mips_m4k_set_breakpoint(struct target *target,
+ struct breakpoint *breakpoint);
+static int mips_m4k_unset_breakpoint(struct target *target,
+ struct breakpoint *breakpoint);
+
+static int mips_m4k_examine_debug_reason(struct target *target)
{
uint32_t break_status;
int retval;
return ERROR_OK;
}
-int mips_m4k_debug_entry(struct target *target)
+static int mips_m4k_debug_entry(struct target *target)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
/* default to mips32 isa, it will be changed below if required */
mips32->isa_mode = MIPS32_ISA_MIPS32;
- if (ejtag_info->impcode & EJTAG_IMP_MIPS16)
- {
- if (buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32) & 0x01)
- {
- /* core is running mips16e isa */
- mips32->isa_mode = MIPS32_ISA_MIPS16E;
- }
+ if (ejtag_info->impcode & EJTAG_IMP_MIPS16) {
+ mips32->isa_mode = buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 1);
}
LOG_DEBUG("entered debug state at PC 0x%" PRIx32 ", target->state: %s",
return ERROR_OK;
}
-int mips_m4k_poll(struct target *target)
+static int mips_m4k_poll(struct target *target)
{
int retval;
struct mips32_common *mips32 = target_to_mips32(target);
uint32_t ejtag_ctrl = ejtag_info->ejtag_ctrl;
/* read ejtag control reg */
- jtag_set_end_state(TAP_IDLE);
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
/* clear this bit before handling polling
{
/* we have detected a reset, clear flag
* otherwise ejtag will not work */
- jtag_set_end_state(TAP_IDLE);
ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_ROCC;
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
LOG_DEBUG("Reset Detected");
}
{
if ((target->state == TARGET_RUNNING) || (target->state == TARGET_RESET))
{
- jtag_set_end_state(TAP_IDLE);
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_NORMALBOOT, NULL);
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_NORMALBOOT);
target->state = TARGET_HALTED;
return ERROR_OK;
}
-int mips_m4k_halt(struct target *target)
+static int mips_m4k_halt(struct target *target)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
return ERROR_OK;
}
-int mips_m4k_assert_reset(struct target *target)
+static int mips_m4k_assert_reset(struct target *target)
{
- struct mips32_common *mips32 = target_to_mips32(target);
- struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
+ struct mips_m4k_common *mips_m4k = target_to_m4k(target);
+ struct mips_ejtag *ejtag_info = &mips_m4k->mips32.ejtag_info;
+ int assert_srst = 1;
LOG_DEBUG("target->state: %s",
target_state_name(target));
enum reset_types jtag_reset_config = jtag_get_reset_config();
+
if (!(jtag_reset_config & RESET_HAS_SRST))
- {
- LOG_ERROR("Can't assert SRST");
- return ERROR_FAIL;
- }
+ assert_srst = 0;
if (target->reset_halt)
{
/* use hardware to catch reset */
- jtag_set_end_state(TAP_IDLE);
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_EJTAGBOOT, NULL);
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_EJTAGBOOT);
}
else
{
- jtag_set_end_state(TAP_IDLE);
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_NORMALBOOT, NULL);
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_NORMALBOOT);
}
- if (strcmp(target->variant, "ejtag_srst") == 0)
- {
- uint32_t ejtag_ctrl = ejtag_info->ejtag_ctrl | EJTAG_CTRL_PRRST | EJTAG_CTRL_PERRST;
- LOG_DEBUG("Using EJTAG reset (PRRST) to reset processor...");
- mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
- mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
- }
- else
+ if (assert_srst)
{
/* here we should issue a srst only, but we may have to assert trst as well */
if (jtag_reset_config & RESET_SRST_PULLS_TRST)
jtag_add_reset(0, 1);
}
}
+ else
+ {
+ if (mips_m4k->is_pic32mx)
+ {
+ uint32_t mchip_cmd;
+
+ LOG_DEBUG("Using MTAP reset to reset processor...");
+
+ /* use microchip specific MTAP reset */
+ mips_ejtag_set_instr(ejtag_info, MTAP_SW_MTAP);
+ mips_ejtag_set_instr(ejtag_info, MTAP_COMMAND);
+
+ mchip_cmd = MCHP_ASERT_RST;
+ mips_ejtag_drscan_8(ejtag_info, &mchip_cmd);
+ mchip_cmd = MCHP_DE_ASSERT_RST;
+ mips_ejtag_drscan_8(ejtag_info, &mchip_cmd);
+ mips_ejtag_set_instr(ejtag_info, MTAP_SW_ETAP);
+ }
+ else
+ {
+ /* use ejtag reset - not supported by all cores */
+ uint32_t ejtag_ctrl = ejtag_info->ejtag_ctrl | EJTAG_CTRL_PRRST | EJTAG_CTRL_PERRST;
+ LOG_DEBUG("Using EJTAG reset (PRRST) to reset processor...");
+ mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
+ mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
+ }
+ }
target->state = TARGET_RESET;
jtag_add_sleep(50000);
- register_cache_invalidate(mips32->core_cache);
+ register_cache_invalidate(mips_m4k->mips32.core_cache);
if (target->reset_halt)
{
return ERROR_OK;
}
-int mips_m4k_deassert_reset(struct target *target)
+static int mips_m4k_deassert_reset(struct target *target)
{
LOG_DEBUG("target->state: %s",
target_state_name(target));
return ERROR_OK;
}
-int mips_m4k_soft_reset_halt(struct target *target)
+static int mips_m4k_soft_reset_halt(struct target *target)
{
/* TODO */
return ERROR_OK;
}
-int mips_m4k_single_step_core(struct target *target)
+static int mips_m4k_single_step_core(struct target *target)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
return ERROR_OK;
}
-int mips_m4k_resume(struct target *target, int current, uint32_t address, int handle_breakpoints, int debug_execution)
+static int mips_m4k_resume(struct target *target, int current,
+ uint32_t address, int handle_breakpoints, int debug_execution)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
mips32->core_cache->reg_list[MIPS32_PC].valid = 1;
}
+ if (ejtag_info->impcode & EJTAG_IMP_MIPS16) {
+ buf_set_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 1, mips32->isa_mode);
+ }
+
resume_pc = buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32);
mips32_restore_context(target);
return ERROR_OK;
}
-int mips_m4k_step(struct target *target, int current, uint32_t address, int handle_breakpoints)
+static int mips_m4k_step(struct target *target, int current,
+ uint32_t address, int handle_breakpoints)
{
/* get pointers to arch-specific information */
struct mips32_common *mips32 = target_to_mips32(target);
buf_set_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32, address);
/* the front-end may request us not to handle breakpoints */
- if (handle_breakpoints)
- if ((breakpoint = breakpoint_find(target, buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32))))
+ if (handle_breakpoints) {
+ breakpoint = breakpoint_find(target,
+ buf_get_u32(mips32->core_cache->reg_list[MIPS32_PC].value, 0, 32));
+ if (breakpoint)
mips_m4k_unset_breakpoint(target, breakpoint);
+ }
/* restore context */
mips32_restore_context(target);
return ERROR_OK;
}
-void mips_m4k_enable_breakpoints(struct target *target)
+static void mips_m4k_enable_breakpoints(struct target *target)
{
struct breakpoint *breakpoint = target->breakpoints;
}
}
-int mips_m4k_set_breakpoint(struct target *target, struct breakpoint *breakpoint)
+static int mips_m4k_set_breakpoint(struct target *target,
+ struct breakpoint *breakpoint)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips32_comparator * comparator_list = mips32->inst_break_list;
{
LOG_ERROR("Can not find free FP Comparator(bpid: %d)",
breakpoint->unique_id );
- return ERROR_FAIL;
+ return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
}
breakpoint->set = bp_num + 1;
comparator_list[bp_num].used = 1;
{
uint32_t verify = 0xffffffff;
- if ((retval = target_read_memory(target, breakpoint->address, breakpoint->length, 1, breakpoint->orig_instr)) != ERROR_OK)
+ if ((retval = target_read_memory(target, breakpoint->address, breakpoint->length, 1,
+ breakpoint->orig_instr)) != ERROR_OK)
{
return retval;
}
{
uint16_t verify = 0xffff;
- if ((retval = target_read_memory(target, breakpoint->address, breakpoint->length, 1, breakpoint->orig_instr)) != ERROR_OK)
+ if ((retval = target_read_memory(target, breakpoint->address, breakpoint->length, 1,
+ breakpoint->orig_instr)) != ERROR_OK)
{
return retval;
}
return ERROR_OK;
}
-int mips_m4k_unset_breakpoint(struct target *target, struct breakpoint *breakpoint)
+static int mips_m4k_unset_breakpoint(struct target *target,
+ struct breakpoint *breakpoint)
{
/* get pointers to arch-specific information */
struct mips32_common *mips32 = target_to_mips32(target);
uint32_t current_instr;
/* check that user program has not modified breakpoint instruction */
- if ((retval = target_read_memory(target, breakpoint->address, 4, 1, (uint8_t*)¤t_instr)) != ERROR_OK)
+ if ((retval = target_read_memory(target, breakpoint->address, 4, 1,
+ (uint8_t*)¤t_instr)) != ERROR_OK)
{
return retval;
}
if (current_instr == MIPS32_SDBBP)
{
- if ((retval = target_write_memory(target, breakpoint->address, 4, 1, breakpoint->orig_instr)) != ERROR_OK)
+ if ((retval = target_write_memory(target, breakpoint->address, 4, 1,
+ breakpoint->orig_instr)) != ERROR_OK)
{
return retval;
}
uint16_t current_instr;
/* check that user program has not modified breakpoint instruction */
- if ((retval = target_read_memory(target, breakpoint->address, 2, 1, (uint8_t*)¤t_instr)) != ERROR_OK)
+ if ((retval = target_read_memory(target, breakpoint->address, 2, 1,
+ (uint8_t*)¤t_instr)) != ERROR_OK)
{
return retval;
}
if (current_instr == MIPS16_SDBBP)
{
- if ((retval = target_write_memory(target, breakpoint->address, 2, 1, breakpoint->orig_instr)) != ERROR_OK)
+ if ((retval = target_write_memory(target, breakpoint->address, 2, 1,
+ breakpoint->orig_instr)) != ERROR_OK)
{
return retval;
}
return ERROR_OK;
}
-int mips_m4k_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
+static int mips_m4k_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
{
struct mips32_common *mips32 = target_to_mips32(target);
mips32->num_inst_bpoints_avail--;
}
- mips_m4k_set_breakpoint(target, breakpoint);
-
- return ERROR_OK;
+ return mips_m4k_set_breakpoint(target, breakpoint);
}
-int mips_m4k_remove_breakpoint(struct target *target, struct breakpoint *breakpoint)
+static int mips_m4k_remove_breakpoint(struct target *target,
+ struct breakpoint *breakpoint)
{
/* get pointers to arch-specific information */
struct mips32_common *mips32 = target_to_mips32(target);
return ERROR_OK;
}
-int mips_m4k_set_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int mips_m4k_set_watchpoint(struct target *target,
+ struct watchpoint *watchpoint)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips32_comparator *comparator_list = mips32->data_break_list;
return ERROR_OK;
}
-int mips_m4k_unset_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int mips_m4k_unset_watchpoint(struct target *target,
+ struct watchpoint *watchpoint)
{
/* get pointers to arch-specific information */
struct mips32_common *mips32 = target_to_mips32(target);
return ERROR_OK;
}
-int mips_m4k_add_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int mips_m4k_add_watchpoint(struct target *target, struct watchpoint *watchpoint)
{
struct mips32_common *mips32 = target_to_mips32(target);
return ERROR_OK;
}
-int mips_m4k_remove_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int mips_m4k_remove_watchpoint(struct target *target,
+ struct watchpoint *watchpoint)
{
/* get pointers to arch-specific information */
struct mips32_common *mips32 = target_to_mips32(target);
return ERROR_OK;
}
-void mips_m4k_enable_watchpoints(struct target *target)
+static void mips_m4k_enable_watchpoints(struct target *target)
{
struct watchpoint *watchpoint = target->watchpoints;
}
}
-int mips_m4k_read_memory(struct target *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
+static int mips_m4k_read_memory(struct target *target, uint32_t address,
+ uint32_t size, uint32_t count, uint8_t *buffer)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
return ERROR_OK;
}
-int mips_m4k_write_memory(struct target *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
+static int mips_m4k_write_memory(struct target *target, uint32_t address,
+ uint32_t size, uint32_t count, uint8_t *buffer)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
- LOG_DEBUG("address: 0x%8.8" PRIx32 ", size: 0x%8.8" PRIx32 ", count: 0x%8.8" PRIx32 "", address, size, count);
+ LOG_DEBUG("address: 0x%8.8" PRIx32 ", size: 0x%8.8" PRIx32 ", count: 0x%8.8" PRIx32 "",
+ address, size, count);
if (target->state != TARGET_HALTED)
{
return mips32_dmaacc_write_mem(ejtag_info, address, size, count, (void *)buffer);
}
-int mips_m4k_init_target(struct command_context *cmd_ctx, struct target *target)
+static int mips_m4k_init_target(struct command_context *cmd_ctx,
+ struct target *target)
{
mips32_build_reg_cache(target);
return ERROR_OK;
}
-int mips_m4k_init_arch_info(struct target *target, struct mips_m4k_common *mips_m4k, struct jtag_tap *tap)
+static int mips_m4k_init_arch_info(struct target *target,
+ struct mips_m4k_common *mips_m4k, struct jtag_tap *tap)
{
- struct mips32_common *mips32 = &mips_m4k->mips32_common;
+ struct mips32_common *mips32 = &mips_m4k->mips32;
mips_m4k->common_magic = MIPSM4K_COMMON_MAGIC;
return ERROR_OK;
}
-int mips_m4k_target_create(struct target *target, Jim_Interp *interp)
+static int mips_m4k_target_create(struct target *target, Jim_Interp *interp)
{
struct mips_m4k_common *mips_m4k = calloc(1, sizeof(struct mips_m4k_common));
return ERROR_OK;
}
-int mips_m4k_examine(struct target *target)
+static int mips_m4k_examine(struct target *target)
{
int retval;
- struct mips32_common *mips32 = target_to_mips32(target);
- struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
+ struct mips_m4k_common *mips_m4k = target_to_m4k(target);
+ struct mips_ejtag *ejtag_info = &mips_m4k->mips32.ejtag_info;
uint32_t idcode = 0;
if (!target_was_examined(target))
{
/* we are using a pic32mx so select ejtag port
* as it is not selected by default */
- mips_ejtag_set_instr(ejtag_info, 0x05, NULL);
+ mips_ejtag_set_instr(ejtag_info, MTAP_SW_ETAP);
LOG_DEBUG("PIC32MX Detected - using EJTAG Interface");
+ mips_m4k->is_pic32mx = true;
}
}
return ERROR_OK;
}
-int mips_m4k_bulk_write_memory(struct target *target, uint32_t address, uint32_t count, uint8_t *buffer)
+static int mips_m4k_bulk_write_memory(struct target *target, uint32_t address,
+ uint32_t count, uint8_t *buffer)
{
struct mips32_common *mips32 = target_to_mips32(target);
struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
- struct working_area *source;
int retval;
- int write = 1;
+ int write_t = 1;
- LOG_DEBUG("address: 0x%8.8x, count: 0x%8.8x", address, count);
+ LOG_DEBUG("address: 0x%8.8" PRIx32 ", count: 0x%8.8" PRIx32 "", address, count);
if (target->state != TARGET_HALTED)
{
if (address & 0x3u)
return ERROR_TARGET_UNALIGNED_ACCESS;
- /* Get memory for block write handler */
- retval = target_alloc_working_area(target, MIPS32_FASTDATA_HANDLER_SIZE, &source);
- if (retval != ERROR_OK)
+ if (mips32->fast_data_area == NULL)
{
- LOG_WARNING("No working area available, falling back to non-bulk write");
- return mips_m4k_write_memory(target, address, 4, count, buffer);
+ /* Get memory for block write handler
+ * we preserve this area between calls and gain a speed increase
+ * of about 3kb/sec when writing flash
+ * this will be released/nulled by the system when the target is resumed or reset */
+ retval = target_alloc_working_area(target,
+ MIPS32_FASTDATA_HANDLER_SIZE,
+ &mips32->fast_data_area);
+ if (retval != ERROR_OK)
+ {
+ LOG_WARNING("No working area available, falling back to non-bulk write");
+ return mips_m4k_write_memory(target, address, 4, count, buffer);
+ }
+
+ /* reset fastadata state so the algo get reloaded */
+ ejtag_info->fast_access_save = -1;
}
/* TAP data register is loaded LSB first (little endian) */
}
}
- retval = mips32_pracc_fastdata_xfer(ejtag_info, source, write, address, count, (uint32_t*) buffer);
+ retval = mips32_pracc_fastdata_xfer(ejtag_info, mips32->fast_data_area, write_t, address,
+ count, (uint32_t*) (void *)buffer);
if (retval != ERROR_OK)
{
/* FASTDATA access failed, try normal memory write */
retval = mips_m4k_write_memory(target, address, 4, count, buffer);
}
- if (source)
- target_free_working_area(target, source);
-
return retval;
}
-int mips_m4k_checksum_memory(struct target *target, uint32_t address, uint32_t size, uint32_t *checksum)
+struct target_type mips_m4k_target =
{
- return ERROR_FAIL; /* use bulk read method */
-}
+ .name = "mips_m4k",
+
+ .poll = mips_m4k_poll,
+ .arch_state = mips32_arch_state,
+
+ .target_request_data = NULL,
+
+ .halt = mips_m4k_halt,
+ .resume = mips_m4k_resume,
+ .step = mips_m4k_step,
+
+ .assert_reset = mips_m4k_assert_reset,
+ .deassert_reset = mips_m4k_deassert_reset,
+ .soft_reset_halt = mips_m4k_soft_reset_halt,
+
+ .get_gdb_reg_list = mips32_get_gdb_reg_list,
+
+ .read_memory = mips_m4k_read_memory,
+ .write_memory = mips_m4k_write_memory,
+ .bulk_write_memory = mips_m4k_bulk_write_memory,
+ .checksum_memory = mips32_checksum_memory,
+ .blank_check_memory = mips32_blank_check_memory,
+
+ .run_algorithm = mips32_run_algorithm,
+
+ .add_breakpoint = mips_m4k_add_breakpoint,
+ .remove_breakpoint = mips_m4k_remove_breakpoint,
+ .add_watchpoint = mips_m4k_add_watchpoint,
+ .remove_watchpoint = mips_m4k_remove_watchpoint,
+
+ .target_create = mips_m4k_target_create,
+ .init_target = mips_m4k_init_target,
+ .examine = mips_m4k_examine,
+};
projects / fw / openocd / blobdiff