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Blind coding new dbus behavior.

This commit is contained in:
Tim Newsome 2016-05-21 21:41:10 -07:00
parent feff2dd9e7
commit 413ab49dfd
1 changed files with 121 additions and 52 deletions
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123
src/target/riscv/riscv.c
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@ -25,6 +25,23 @@
#define DTMINFO_VERSION (0xf)
#define DBUS 0x11
#define DBUS_OP_START 0
#define DBUS_OP_SIZE 2
typedef enum {
DBUS_OP_NOP = 0,
DBUS_OP_READ = 1,
DBUS_OP_WRITE = 2,
DBUS_OP_CONDITIONAL_WRITE = 3
} dbus_op_t;
typedef enum {
DBUS_RESULT_SUCCESS = 0,
DBUS_RESULT_NO_WRITE = 1,
DBUS_RESULT_FAILED = 2,
DBUS_RESULT_BUSY = 3
} dbus_result_t;
#define DBUS_DATA_START 2
#define DBUS_DATA_SIZE 34
#define DBUS_ADDRESS_START 36
/*** Debug Bus registers. ***/
@ -65,6 +82,8 @@ typedef struct {
/* Last value we wrote to DBUS_ADDRESS (eg. the address of the register
* whose value will be read the next time we scan dbus). */
uint16_t dbus_address;
/* Last op we wrote to dbus. */
dbus_op_t dbus_op;
/* Number of words in Debug RAM. */
unsigned int dramsize;
/* Our local copy of Debug RAM. */
@ -78,18 +97,26 @@ typedef struct {
/*** Utility functions. ***/
static uint8_t ir_dtminfo[1] = {DTMINFO};
static struct scan_field scan_dtminfo = {
static struct scan_field select_dtminfo = {
.in_value = NULL,
.out_value = ir_dtminfo
};
static uint8_t ir_dbus[1] = {DBUS};
static struct scan_field scan_dbus = {
static struct scan_field select_dbus = {
.in_value = NULL,
.out_value = ir_dbus
};
static uint64_t dbus_scan(struct target *target, uint16_t address,
uint64_t data_out, bool read, bool write)
static uint16_t dram_address(unsigned int index)
{
if (index < 0x10)
return index;
else
return 0x40 + index - 0x10;
}
static dbus_result_t dbus_scan(struct target *target, uint64_t *data_in,
dbus_op_t op, uint16_t address, uint64_t data_out)
{
riscv_info_t *info = (riscv_info_t *) target->arch_info;
struct scan_field field;
@ -98,17 +125,17 @@ static uint64_t dbus_scan(struct target *target, uint16_t address,
assert(info->addrbits != 0);
// TODO: max bits is 32?
field.num_bits = info->addrbits + 35;
field.num_bits = info->addrbits + DBUS_OP_SIZE + DBUS_DATA_SIZE;
field.out_value = out;
field.in_value = in;
buf_set_u64(out, 0, 34, data_out);
buf_set_u64(out, 34, info->addrbits, address);
buf_set_u64(out, info->addrbits + 34, 1, write);
buf_set_u64(out, DBUS_OP_START, DBUS_OP_SIZE, op);
buf_set_u64(out, DBUS_DATA_START, DBUS_DATA_SIZE, data_out);
buf_set_u64(out, DBUS_ADDRESS_START, info->addrbits, address);
/* Assume dbus is already selected. */
jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
info->dbus_address = address;
info->dbus_op = op;
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
@ -116,22 +143,43 @@ static uint64_t dbus_scan(struct target *target, uint16_t address,
return retval;
}
return buf_get_u64(in, 0, 34);
if (data_in) {
*data_in = buf_get_u64(in, DBUS_DATA_START, DBUS_DATA_SIZE);
}
return buf_get_u64(in, DBUS_OP_START, DBUS_OP_SIZE);
}
static uint64_t dbus_read(struct target *target, uint16_t address, uint16_t next_address)
{
riscv_info_t *info = (riscv_info_t *) target->arch_info;
uint64_t value;
if (address != info->dbus_address) {
dbus_scan(target, address, 0, false, false);
dbus_result_t result = DBUS_RESULT_BUSY;
if (address != info->dbus_address || info->dbus_op == DBUS_OP_NOP) {
while (result == DBUS_RESULT_BUSY) {
result = dbus_scan(target, NULL, DBUS_OP_READ, address, 0);
}
return dbus_scan(target, next_address, 0, true, false);
}
result = DBUS_RESULT_BUSY;
while (result == DBUS_RESULT_BUSY) {
result = dbus_scan(target, &value, DBUS_OP_READ, next_address, 0);
}
if (result != DBUS_RESULT_SUCCESS) {
LOG_ERROR("dbus_read failed read at 0x%x; result=%d\n", address, result);
}
return value;
}
static uint64_t dbus_write(struct target *target, uint16_t address, uint64_t value)
static void dbus_write(struct target *target, uint16_t address, uint64_t value)
{
return dbus_scan(target, address, value, false, true);
dbus_result_t result = DBUS_RESULT_BUSY;
while (result == DBUS_RESULT_BUSY) {
result = dbus_scan(target, NULL, DBUS_OP_WRITE, address, value);
}
if (result != DBUS_RESULT_SUCCESS) {
LOG_ERROR("dbus_write failed write 0x%lx to 0x%x; result=%d\n", value,
address, result);
}
}
static uint32_t dtminfo_read(struct target *target)
@ -139,7 +187,7 @@ static uint32_t dtminfo_read(struct target *target)
struct scan_field field;
uint8_t in[4];
jtag_add_ir_scan(target->tap, &scan_dtminfo, TAP_IDLE);
jtag_add_ir_scan(target->tap, &select_dtminfo, TAP_IDLE);
field.num_bits = 32;
field.out_value = NULL;
@ -148,7 +196,7 @@ static uint32_t dtminfo_read(struct target *target)
int retval = jtag_execute_queue();
if (retval != ERROR_OK) {
LOG_ERROR("dbus_scan failed jtag scan");
LOG_ERROR("dtminfo_read failed jtag scan");
return retval;
}
@ -156,24 +204,37 @@ static uint32_t dtminfo_read(struct target *target)
/* TODO: Can we rely on IR not being messed with between calls into
* RISCV code? Eg. what happens if there are multiple cores and some
* other core is accessed? */
jtag_add_ir_scan(target->tap, &scan_dbus, TAP_IDLE);
jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
return buf_get_u32(field.in_value, 0, 32);
}
static uint32_t dram_read32(struct target *target, unsigned int index,
bool set_interrupt)
{
// TODO: check cache to see if this even needs doing.
uint16_t address = dram_address(index);
return dbus_read(target, address, address);
}
static void dram_write32(struct target *target, unsigned int index, uint32_t value,
bool set_interrupt)
{
// TODO: check cache to see this even needs doing.
uint16_t address;
if (index < 0x10)
address = index;
else
address = 0x40 + index - 0x10;
// TODO: check cache to see if this even needs doing.
uint64_t dbus_value = DMCONTROL_HALTNOT | value;
if (set_interrupt)
dbus_value |= DMCONTROL_INTERRUPT;
dbus_write(target, address, dbus_value);
dbus_write(target, dram_address(index), dbus_value);
}
static void dram_check32(struct target *target, unsigned int index,
uint32_t expected)
{
uint32_t actual = dram_read32(target, index, false);
if (expected != actual) {
LOG_ERROR("Wrote 0x%x to Debug RAM at %d, but read back 0x%x",
expected, index, actual);
}
}
/* Write instruction that jumps from the specified word in Debug RAM to resume
@ -196,9 +257,10 @@ static int riscv_init_target(struct command_context *cmd_ctx,
return ERROR_FAIL;
riscv_info_t *info = (riscv_info_t *) target->arch_info;
info->dbus_address = DBUS_ADDRESS_UNKNOWN;
info->dbus_op = DBUS_OP_NOP;
scan_dtminfo.num_bits = target->tap->ir_length;
scan_dbus.num_bits = target->tap->ir_length;
select_dtminfo.num_bits = target->tap->ir_length;
select_dbus.num_bits = target->tap->ir_length;
return ERROR_OK;
}
@ -254,6 +316,13 @@ static int riscv_examine(struct target *target)
dram_write32(target, 4, sw(S1, ZERO, DEBUG_RAM_START + 4), false);
dram_write_jump(target, 5, true);
// Check that we can actually read/write dram.
dram_check32(target, 0, xori(S1, ZERO, -1));
dram_check32(target, 1, srli(S1, S1, 31));
dram_check32(target, 2, sw(S1, ZERO, DEBUG_RAM_START));
dram_check32(target, 3, srli(S1, S1, 31));
dram_check32(target, 4, sw(S1, ZERO, DEBUG_RAM_START + 4));
target_set_examined(target);
return ERROR_OK;