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Diffstat (limited to 'src/target/arm_simulator.c')
-rw-r--r--src/target/arm_simulator.c338
1 files changed, 101 insertions, 237 deletions
diff --git a/src/target/arm_simulator.c b/src/target/arm_simulator.c
index a0ffdde..215739d 100644
--- a/src/target/arm_simulator.c
+++ b/src/target/arm_simulator.c
@@ -20,6 +20,7 @@
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
@@ -32,51 +33,32 @@
#include "register.h"
#include <helper/log.h>
-
static uint32_t arm_shift(uint8_t shift, uint32_t Rm,
- uint32_t shift_amount, uint8_t *carry)
+ uint32_t shift_amount, uint8_t *carry)
{
uint32_t return_value = 0;
shift_amount &= 0xff;
- if (shift == 0x0) /* LSL */
- {
- if ((shift_amount > 0) && (shift_amount <= 32))
- {
+ if (shift == 0x0) { /* LSL */
+ if ((shift_amount > 0) && (shift_amount <= 32)) {
return_value = Rm << shift_amount;
*carry = Rm >> (32 - shift_amount);
- }
- else if (shift_amount > 32)
- {
+ } else if (shift_amount > 32) {
return_value = 0x0;
*carry = 0x0;
- }
- else /* (shift_amount == 0) */
- {
+ } else /* (shift_amount == 0) */
return_value = Rm;
- }
- }
- else if (shift == 0x1) /* LSR */
- {
- if ((shift_amount > 0) && (shift_amount <= 32))
- {
+ } else if (shift == 0x1) { /* LSR */
+ if ((shift_amount > 0) && (shift_amount <= 32)) {
return_value = Rm >> shift_amount;
*carry = (Rm >> (shift_amount - 1)) & 1;
- }
- else if (shift_amount > 32)
- {
+ } else if (shift_amount > 32) {
return_value = 0x0;
*carry = 0x0;
- }
- else /* (shift_amount == 0) */
- {
+ } else /* (shift_amount == 0) */
return_value = Rm;
- }
- }
- else if (shift == 0x2) /* ASR */
- {
- if ((shift_amount > 0) && (shift_amount <= 32))
- {
+ } else if (shift == 0x2) { /* ASR */
+ if ((shift_amount > 0) && (shift_amount <= 32)) {
/* C right shifts of unsigned values are guaranteed to
* be logical (shift in zeroes); simulate an arithmetic
* shift (shift in signed-bit) by adding the sign bit
@@ -85,40 +67,25 @@ static uint32_t arm_shift(uint8_t shift, uint32_t Rm,
return_value = Rm >> shift_amount;
if (Rm & 0x80000000)
return_value |= 0xffffffff << (32 - shift_amount);
- }
- else if (shift_amount > 32)
- {
- if (Rm & 0x80000000)
- {
+ } else if (shift_amount > 32) {
+ if (Rm & 0x80000000) {
return_value = 0xffffffff;
*carry = 0x1;
- }
- else
- {
+ } else {
return_value = 0x0;
*carry = 0x0;
}
- }
- else /* (shift_amount == 0) */
- {
+ } else /* (shift_amount == 0) */
return_value = Rm;
- }
- }
- else if (shift == 0x3) /* ROR */
- {
+ } else if (shift == 0x3) { /* ROR */
if (shift_amount == 0)
- {
return_value = Rm;
- }
- else
- {
+ else {
shift_amount = shift_amount % 32;
return_value = (Rm >> shift_amount) | (Rm << (32 - shift_amount));
*carry = (return_value >> 31) & 0x1;
}
- }
- else if (shift == 0x4) /* RRX */
- {
+ } else if (shift == 0x4) { /* RRX */
return_value = Rm >> 1;
if (*carry)
Rm |= 0x80000000;
@@ -130,8 +97,8 @@ static uint32_t arm_shift(uint8_t shift, uint32_t Rm,
static uint32_t arm_shifter_operand(struct arm_sim_interface *sim,
- int variant, union arm_shifter_operand shifter_operand,
- uint8_t *shifter_carry_out)
+ int variant, union arm_shifter_operand shifter_operand,
+ uint8_t *shifter_carry_out)
{
uint32_t return_value;
int instruction_size;
@@ -144,11 +111,8 @@ static uint32_t arm_shifter_operand(struct arm_sim_interface *sim,
*shifter_carry_out = sim->get_cpsr(sim, 29, 1);
if (variant == 0) /* 32-bit immediate */
- {
return_value = shifter_operand.immediate.immediate;
- }
- else if (variant == 1) /* immediate shift */
- {
+ else if (variant == 1) {/* immediate shift */
uint32_t Rm = sim->get_reg_mode(sim, shifter_operand.immediate_shift.Rm);
/* adjust RM in case the PC is being read */
@@ -158,9 +122,7 @@ static uint32_t arm_shifter_operand(struct arm_sim_interface *sim,
return_value = arm_shift(shifter_operand.immediate_shift.shift,
Rm, shifter_operand.immediate_shift.shift_imm,
shifter_carry_out);
- }
- else if (variant == 2) /* register shift */
- {
+ } else if (variant == 2) { /* register shift */
uint32_t Rm = sim->get_reg_mode(sim, shifter_operand.register_shift.Rm);
uint32_t Rs = sim->get_reg_mode(sim, shifter_operand.register_shift.Rs);
@@ -170,9 +132,7 @@ static uint32_t arm_shifter_operand(struct arm_sim_interface *sim,
return_value = arm_shift(shifter_operand.immediate_shift.shift,
Rm, Rs, shifter_carry_out);
- }
- else
- {
+ } else {
LOG_ERROR("BUG: shifter_operand.variant not 0, 1 or 2");
return_value = 0xffffffff;
}
@@ -182,8 +142,7 @@ static uint32_t arm_shifter_operand(struct arm_sim_interface *sim,
static int pass_condition(uint32_t cpsr, uint32_t opcode)
{
- switch ((opcode & 0xf0000000) >> 28)
- {
+ switch ((opcode & 0xf0000000) >> 28) {
case 0x0: /* EQ */
if (cpsr & 0x40000000)
return 1;
@@ -280,45 +239,35 @@ static int thumb_pass_branch_condition(uint32_t cpsr, uint16_t opcode)
* but the new pc is stored in the variable pointed at by the argument
*/
static int arm_simulate_step_core(struct target *target,
- uint32_t *dry_run_pc, struct arm_sim_interface *sim)
+ uint32_t *dry_run_pc, struct arm_sim_interface *sim)
{
uint32_t current_pc = sim->get_reg(sim, 15);
struct arm_instruction instruction;
int instruction_size;
int retval = ERROR_OK;
- if (sim->get_state(sim) == ARM_STATE_ARM)
- {
+ if (sim->get_state(sim) == ARM_STATE_ARM) {
uint32_t opcode;
/* get current instruction, and identify it */
- if ((retval = target_read_u32(target, current_pc, &opcode)) != ERROR_OK)
- {
+ retval = target_read_u32(target, current_pc, &opcode);
+ if (retval != ERROR_OK)
return retval;
- }
- if ((retval = arm_evaluate_opcode(opcode, current_pc, &instruction)) != ERROR_OK)
- {
+ retval = arm_evaluate_opcode(opcode, current_pc, &instruction);
+ if (retval != ERROR_OK)
return retval;
- }
instruction_size = 4;
/* check condition code (for all instructions) */
- if (!pass_condition(sim->get_cpsr(sim, 0, 32), opcode))
- {
+ if (!pass_condition(sim->get_cpsr(sim, 0, 32), opcode)) {
if (dry_run_pc)
- {
*dry_run_pc = current_pc + instruction_size;
- }
else
- {
sim->set_reg(sim, 15, current_pc + instruction_size);
- }
return ERROR_OK;
}
- }
- else
- {
+ } else {
uint16_t opcode;
retval = target_read_u16(target, current_pc, &opcode);
@@ -331,17 +280,12 @@ static int arm_simulate_step_core(struct target *target,
/* check condition code (only for branch (1) instructions) */
if ((opcode & 0xf000) == 0xd000
- && !thumb_pass_branch_condition(
- sim->get_cpsr(sim, 0, 32), opcode))
- {
+ && !thumb_pass_branch_condition(
+ sim->get_cpsr(sim, 0, 32), opcode)) {
if (dry_run_pc)
- {
*dry_run_pc = current_pc + instruction_size;
- }
else
- {
sim->set_reg(sim, 15, current_pc + instruction_size);
- }
return ERROR_OK;
}
@@ -362,67 +306,44 @@ static int arm_simulate_step_core(struct target *target,
/* examine instruction type */
/* branch instructions */
- if ((instruction.type >= ARM_B) && (instruction.type <= ARM_BLX))
- {
+ if ((instruction.type >= ARM_B) && (instruction.type <= ARM_BLX)) {
uint32_t target_address;
if (instruction.info.b_bl_bx_blx.reg_operand == -1)
- {
target_address = instruction.info.b_bl_bx_blx.target_address;
- }
- else
- {
- target_address = sim->get_reg_mode(sim, instruction.info.b_bl_bx_blx.reg_operand);
+ else {
+ target_address = sim->get_reg_mode(sim,
+ instruction.info.b_bl_bx_blx.reg_operand);
if (instruction.info.b_bl_bx_blx.reg_operand == 15)
- {
target_address += 2 * instruction_size;
- }
}
- if (dry_run_pc)
- {
+ if (dry_run_pc) {
*dry_run_pc = target_address & ~1;
return ERROR_OK;
- }
- else
- {
+ } else {
if (instruction.type == ARM_B)
- {
sim->set_reg(sim, 15, target_address);
- }
- else if (instruction.type == ARM_BL)
- {
+ else if (instruction.type == ARM_BL) {
uint32_t old_pc = sim->get_reg(sim, 15);
int T = (sim->get_state(sim) == ARM_STATE_THUMB);
sim->set_reg_mode(sim, 14, old_pc + 4 + T);
sim->set_reg(sim, 15, target_address);
- }
- else if (instruction.type == ARM_BX)
- {
+ } else if (instruction.type == ARM_BX) {
if (target_address & 0x1)
- {
sim->set_state(sim, ARM_STATE_THUMB);
- }
else
- {
sim->set_state(sim, ARM_STATE_ARM);
- }
sim->set_reg(sim, 15, target_address & 0xfffffffe);
- }
- else if (instruction.type == ARM_BLX)
- {
+ } else if (instruction.type == ARM_BLX) {
uint32_t old_pc = sim->get_reg(sim, 15);
int T = (sim->get_state(sim) == ARM_STATE_THUMB);
sim->set_reg_mode(sim, 14, old_pc + 4 + T);
if (target_address & 0x1)
- {
sim->set_state(sim, ARM_STATE_THUMB);
- }
else
- {
sim->set_state(sim, ARM_STATE_ARM);
- }
sim->set_reg(sim, 15, target_address & 0xfffffffe);
}
@@ -431,8 +352,7 @@ static int arm_simulate_step_core(struct target *target,
}
/* data processing instructions, except compare instructions (CMP, CMN, TST, TEQ) */
else if (((instruction.type >= ARM_AND) && (instruction.type <= ARM_RSC))
- || ((instruction.type >= ARM_ORR) && (instruction.type <= ARM_MVN)))
- {
+ || ((instruction.type >= ARM_ORR) && (instruction.type <= ARM_MVN))) {
uint32_t Rd, Rn, shifter_operand;
uint8_t C = sim->get_cpsr(sim, 29, 1);
uint8_t carry_out;
@@ -480,17 +400,14 @@ static int arm_simulate_step_core(struct target *target,
else
LOG_WARNING("unhandled instruction type");
- if (dry_run_pc)
- {
+ if (dry_run_pc) {
if (instruction.info.data_proc.Rd == 15)
*dry_run_pc = Rd & ~1;
else
*dry_run_pc = current_pc + instruction_size;
return ERROR_OK;
- }
- else
- {
+ } else {
if (instruction.info.data_proc.Rd == 15) {
sim->set_reg_mode(sim, 15, Rd & ~1);
if (Rd & 1)
@@ -504,21 +421,15 @@ static int arm_simulate_step_core(struct target *target,
}
}
/* compare instructions (CMP, CMN, TST, TEQ) */
- else if ((instruction.type >= ARM_TST) && (instruction.type <= ARM_CMN))
- {
- if (dry_run_pc)
- {
+ else if ((instruction.type >= ARM_TST) && (instruction.type <= ARM_CMN)) {
+ if (dry_run_pc) {
*dry_run_pc = current_pc + instruction_size;
return ERROR_OK;
- }
- else
- {
+ } else
LOG_WARNING("no updating of flags yet");
- }
}
/* load register instructions */
- else if ((instruction.type >= ARM_LDR) && (instruction.type <= ARM_LDRSH))
- {
+ else if ((instruction.type >= ARM_LDR) && (instruction.type <= ARM_LDRSH)) {
uint32_t load_address = 0, modified_address = 0, load_value = 0;
uint32_t Rn = sim->get_reg_mode(sim, instruction.info.load_store.Rn);
@@ -526,15 +437,12 @@ static int arm_simulate_step_core(struct target *target,
if (instruction.info.load_store.Rn == 15)
Rn += 2 * instruction_size;
- if (instruction.info.load_store.offset_mode == 0)
- {
+ if (instruction.info.load_store.offset_mode == 0) {
if (instruction.info.load_store.U)
modified_address = Rn + instruction.info.load_store.offset.offset;
else
modified_address = Rn - instruction.info.load_store.offset.offset;
- }
- else if (instruction.info.load_store.offset_mode == 1)
- {
+ } else if (instruction.info.load_store.offset_mode == 1) {
uint32_t offset;
uint32_t Rm = sim->get_reg_mode(sim,
instruction.info.load_store.offset.reg.Rm);
@@ -548,31 +456,23 @@ static int arm_simulate_step_core(struct target *target,
modified_address = Rn + offset;
else
modified_address = Rn - offset;
- }
- else
- {
+ } else
LOG_ERROR("BUG: offset_mode neither 0 (offset) nor 1 (scaled register)");
- }
- if (instruction.info.load_store.index_mode == 0)
- {
+ if (instruction.info.load_store.index_mode == 0) {
/* offset mode
* we load from the modified address, but don't change
* the base address register
*/
load_address = modified_address;
modified_address = Rn;
- }
- else if (instruction.info.load_store.index_mode == 1)
- {
+ } else if (instruction.info.load_store.index_mode == 1) {
/* pre-indexed mode
* we load from the modified address, and write it
* back to the base address register
*/
load_address = modified_address;
- }
- else if (instruction.info.load_store.index_mode == 2)
- {
+ } else if (instruction.info.load_store.index_mode == 2) {
/* post-indexed mode
* we load from the unmodified address, and write the
* modified address back
@@ -580,28 +480,24 @@ static int arm_simulate_step_core(struct target *target,
load_address = Rn;
}
- if ((!dry_run_pc) || (instruction.info.load_store.Rd == 15))
- {
+ if ((!dry_run_pc) || (instruction.info.load_store.Rd == 15)) {
retval = target_read_u32(target, load_address, &load_value);
if (retval != ERROR_OK)
return retval;
}
- if (dry_run_pc)
- {
+ if (dry_run_pc) {
if (instruction.info.load_store.Rd == 15)
*dry_run_pc = load_value & ~1;
else
*dry_run_pc = current_pc + instruction_size;
return ERROR_OK;
- }
- else
- {
+ } else {
if ((instruction.info.load_store.index_mode == 1) ||
(instruction.info.load_store.index_mode == 2))
- {
- sim->set_reg_mode(sim, instruction.info.load_store.Rn, modified_address);
- }
+ sim->set_reg_mode(sim,
+ instruction.info.load_store.Rn,
+ modified_address);
if (instruction.info.load_store.Rd == 15) {
sim->set_reg_mode(sim, 15, load_value & ~1);
@@ -615,84 +511,68 @@ static int arm_simulate_step_core(struct target *target,
}
}
/* load multiple instruction */
- else if (instruction.type == ARM_LDM)
- {
+ else if (instruction.type == ARM_LDM) {
int i;
uint32_t Rn = sim->get_reg_mode(sim, instruction.info.load_store_multiple.Rn);
uint32_t load_values[16];
int bits_set = 0;
- for (i = 0; i < 16; i++)
- {
+ for (i = 0; i < 16; i++) {
if (instruction.info.load_store_multiple.register_list & (1 << i))
bits_set++;
}
- switch (instruction.info.load_store_multiple.addressing_mode)
- {
- case 0: /* Increment after */
+ switch (instruction.info.load_store_multiple.addressing_mode) {
+ case 0: /* Increment after */
Rn = Rn;
break;
- case 1: /* Increment before */
+ case 1: /* Increment before */
Rn = Rn + 4;
break;
- case 2: /* Decrement after */
+ case 2: /* Decrement after */
Rn = Rn - (bits_set * 4) + 4;
break;
- case 3: /* Decrement before */
+ case 3: /* Decrement before */
Rn = Rn - (bits_set * 4);
break;
}
- for (i = 0; i < 16; i++)
- {
- if (instruction.info.load_store_multiple.register_list & (1 << i))
- {
+ for (i = 0; i < 16; i++) {
+ if (instruction.info.load_store_multiple.register_list & (1 << i)) {
if ((!dry_run_pc) || (i == 15))
- {
target_read_u32(target, Rn, &load_values[i]);
- }
Rn += 4;
}
}
- if (dry_run_pc)
- {
- if (instruction.info.load_store_multiple.register_list & 0x8000)
- {
+ if (dry_run_pc) {
+ if (instruction.info.load_store_multiple.register_list & 0x8000) {
*dry_run_pc = load_values[15] & ~1;
return ERROR_OK;
}
- }
- else
- {
+ } else {
int update_cpsr = 0;
- if (instruction.info.load_store_multiple.S)
- {
+ if (instruction.info.load_store_multiple.S) {
if (instruction.info.load_store_multiple.register_list & 0x8000)
update_cpsr = 1;
}
- for (i = 0; i < 16; i++)
- {
- if (instruction.info.load_store_multiple.register_list & (1 << i))
- {
+ for (i = 0; i < 16; i++) {
+ if (instruction.info.load_store_multiple.register_list & (1 << i)) {
if (i == 15) {
uint32_t val = load_values[i];
- sim->set_reg_mode(sim, i, val & ~1);
- if (val & 1)
- sim->set_state(sim, ARM_STATE_THUMB);
- else
- sim->set_state(sim, ARM_STATE_ARM);
- } else {
+ sim->set_reg_mode(sim, i, val & ~1);
+ if (val & 1)
+ sim->set_state(sim, ARM_STATE_THUMB);
+ else
+ sim->set_state(sim, ARM_STATE_ARM);
+ } else
sim->set_reg_mode(sim, i, load_values[i]);
- }
}
}
- if (update_cpsr)
- {
+ if (update_cpsr) {
uint32_t spsr = sim->get_reg_mode(sim, 16);
sim->set_reg(sim, ARMV4_5_CPSR, spsr);
}
@@ -701,51 +581,44 @@ static int arm_simulate_step_core(struct target *target,
if (instruction.info.load_store_multiple.W)
sim->set_reg_mode(sim, instruction.info.load_store_multiple.Rn, Rn);
+
if (instruction.info.load_store_multiple.register_list & 0x8000)
return ERROR_OK;
}
}
/* store multiple instruction */
- else if (instruction.type == ARM_STM)
- {
+ else if (instruction.type == ARM_STM) {
int i;
- if (dry_run_pc)
- {
+ if (dry_run_pc) {
/* STM wont affect PC (advance by instruction size */
- }
- else
- {
+ } else {
uint32_t Rn = sim->get_reg_mode(sim,
instruction.info.load_store_multiple.Rn);
int bits_set = 0;
- for (i = 0; i < 16; i++)
- {
+ for (i = 0; i < 16; i++) {
if (instruction.info.load_store_multiple.register_list & (1 << i))
bits_set++;
}
- switch (instruction.info.load_store_multiple.addressing_mode)
- {
- case 0: /* Increment after */
+ switch (instruction.info.load_store_multiple.addressing_mode) {
+ case 0: /* Increment after */
Rn = Rn;
break;
- case 1: /* Increment before */
+ case 1: /* Increment before */
Rn = Rn + 4;
break;
- case 2: /* Decrement after */
+ case 2: /* Decrement after */
Rn = Rn - (bits_set * 4) + 4;
break;
- case 3: /* Decrement before */
+ case 3: /* Decrement before */
Rn = Rn - (bits_set * 4);
break;
}
- for (i = 0; i < 16; i++)
- {
- if (instruction.info.load_store_multiple.register_list & (1 << i))
- {
+ for (i = 0; i < 16; i++) {
+ if (instruction.info.load_store_multiple.register_list & (1 << i)) {
target_write_u32(target, Rn, sim->get_reg_mode(sim, i));
Rn += 4;
}
@@ -757,22 +630,17 @@ static int arm_simulate_step_core(struct target *target,
instruction.info.load_store_multiple.Rn, Rn);
}
- }
- else if (!dry_run_pc)
- {
+ } else if (!dry_run_pc) {
/* the instruction wasn't handled, but we're supposed to simulate it
*/
LOG_ERROR("Unimplemented instruction, could not simulate it.");
return ERROR_FAIL;
}
- if (dry_run_pc)
- {
+ if (dry_run_pc) {
*dry_run_pc = current_pc + instruction_size;
return ERROR_OK;
- }
- else
- {
+ } else {
sim->set_reg(sim, 15, current_pc + instruction_size);
return ERROR_OK;
}
@@ -806,7 +674,7 @@ static void armv4_5_set_reg_mode(struct arm_sim_interface *sim, int reg, uint32_
struct arm *arm = (struct arm *)sim->user_data;
buf_set_u32(ARMV4_5_CORE_REG_MODE(arm->core_cache,
- arm->core_mode, reg).value, 0, 32, value);
+ arm->core_mode, reg).value, 0, 32, value);
}
static uint32_t armv4_5_get_cpsr(struct arm_sim_interface *sim, int pos, int bits)
@@ -830,7 +698,6 @@ static void armv4_5_set_state(struct arm_sim_interface *sim, enum arm_state mode
arm->core_state = mode;
}
-
static enum arm_mode armv4_5_get_mode(struct arm_sim_interface *sim)
{
struct arm *arm = (struct arm *)sim->user_data;
@@ -838,8 +705,6 @@ static enum arm_mode armv4_5_get_mode(struct arm_sim_interface *sim)
return arm->core_mode;
}
-
-
int arm_simulate_step(struct target *target, uint32_t *dry_run_pc)
{
struct arm *arm = target_to_arm(target);
@@ -857,4 +722,3 @@ int arm_simulate_step(struct target *target, uint32_t *dry_run_pc)
return arm_simulate_step_core(target, dry_run_pc, &sim);
}
-
generated by cgit v1.1 at 2024-11-17 11:30:33 +0000