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tinyriscv-openocd
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Fix access FPU registers again. 

Not a great fix. There's still a problem with accessing 64-bit floating
point registers on 32-bit cores.
24 of the gdbserver.py tests pass now.

Change-Id: I69a88ef5fd5581e2c7bf1d78057fd474ae86ff93
__archive__
Tim Newsome 2017-02-17 19:03:32 -08:00
parent 071f9a2916
commit 3173314f28
1 changed files with 80 additions and 46 deletions
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130
src/target/riscv/riscv-013.c
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@ -219,7 +219,7 @@ static riscv013_info_t *get_info(const struct target *target)
return (riscv013_info_t *) info->version_specific;
}
bool extension_supported(struct target *target, char letter)
bool supports_extension(struct target *target, char letter)
{
riscv013_info_t *info = get_info(target);
unsigned num;
@ -769,43 +769,19 @@ static int abstract_write_register(struct target *target,
return ERROR_OK;
}
/** Actually read registers from the target right now. */
static int register_read_direct(struct target *target, uint64_t *value, uint32_t number)
static int update_mstatus_actual(struct target *target)
{
int result = abstract_read_register(target, value, number, xlen(target));
if (result == ERROR_OK)
return result;
// Fall back to program buffer.
if (number >= REG_FPR0 && number <= REG_FPR31) {
program_t *program = program_new();
if (extension_supported(target, 'D')) {
program_add32(program, fmv_x_d(S0, number - REG_FPR0));
} else {
program_add32(program, fmv_x_s(S0, number - REG_FPR0));
}
program_add32(program, ebreak());
program_set_read(program, S0);
execute_program(target, program);
program_delete(program);
} else if (number >= REG_CSR0 && number <= REG_CSR4095) {
program_t *program = program_new();
program_add32(program, csrr(S0, number - REG_CSR0));
program_add32(program, ebreak());
program_set_read(program, S0);
execute_program(target, program);
program_delete(program);
} else {
return result;
}
result = register_read_direct(target, value, S0);
if (result != ERROR_OK)
return result;
LOG_DEBUG("register 0x%x = 0x%" PRIx64, number, *value);
struct reg *mstatus_reg = &target->reg_cache->reg_list[REG_MSTATUS];
if (mstatus_reg->valid) {
// We previously made it valid.
return ERROR_OK;
}
LOG_DEBUG("Reading mstatus");
// Force reading the register. In that process mstatus_actual will be
// updated.
return register_get(&target->reg_cache->reg_list[REG_MSTATUS]);
}
static int register_write_direct(struct target *target, unsigned number,
@ -824,8 +800,20 @@ static int register_write_direct(struct target *target, unsigned number,
// Fall back to program buffer.
if (number >= REG_FPR0 && number <= REG_FPR31) {
result = update_mstatus_actual(target);
if (result != ERROR_OK) {
return result;
}
if ((info->mstatus_actual & MSTATUS_FS) == 0) {
result = register_write_direct(target, REG_MSTATUS,
set_field(info->mstatus_actual, MSTATUS_FS, 1));
if (result != ERROR_OK)
return result;
}
program_t *program = program_new();
if (extension_supported(target, 'D')) {
// TODO: Fully support D extension on RV32.
if (supports_extension(target, 'D') && xlen(target) >= 64) {
program_add32(program, fmv_d_x(number - REG_FPR0, S0));
} else {
program_add32(program, fmv_s_x(number - REG_FPR0, S0));
@ -848,6 +836,61 @@ static int register_write_direct(struct target *target, unsigned number,
return result;
}
/** Actually read registers from the target right now. */
static int register_read_direct(struct target *target, uint64_t *value, uint32_t number)
{
riscv013_info_t *info = get_info(target);
int result = abstract_read_register(target, value, number, xlen(target));
if (result == ERROR_OK)
return result;
// Fall back to program buffer.
if (number >= REG_FPR0 && number <= REG_FPR31) {
result = update_mstatus_actual(target);
if (result != ERROR_OK) {
return result;
}
if ((info->mstatus_actual & MSTATUS_FS) == 0) {
result = register_write_direct(target, REG_MSTATUS,
set_field(info->mstatus_actual, MSTATUS_FS, 1));
if (result != ERROR_OK)
return result;
}
LOG_DEBUG("mstatus_actual=0x%lx", info->mstatus_actual);
program_t *program = program_new();
if (supports_extension(target, 'D') && xlen(target) >= 64) {
program_add32(program, fmv_x_d(S0, number - REG_FPR0));
} else {
program_add32(program, fmv_x_s(S0, number - REG_FPR0));
}
program_add32(program, ebreak());
program_set_read(program, S0);
result = execute_program(target, program);
program_delete(program);
} else if (number >= REG_CSR0 && number <= REG_CSR4095) {
program_t *program = program_new();
program_add32(program, csrr(S0, number - REG_CSR0));
program_add32(program, ebreak());
program_set_read(program, S0);
result = execute_program(target, program);
program_delete(program);
} else {
return result;
}
if (result != ERROR_OK)
return result;
result = register_read_direct(target, value, S0);
if (result != ERROR_OK)
return result;
LOG_DEBUG("register 0x%x = 0x%" PRIx64, number, *value);
return ERROR_OK;
}
static int maybe_read_tselect(struct target *target)
{
riscv013_info_t *info = get_info(target);
@ -1067,21 +1110,12 @@ static int register_write(struct target *target, unsigned int number,
maybe_write_tselect(target);
if (number <= REG_XPR31) {
return abstract_write_register(target, number, xlen(target), value);
} else if (number == REG_PC) {
if (number == REG_PC) {
info->dpc = value;
return ERROR_OK;
} else if (number >= REG_FPR0 && number <= REG_FPR31) {
return abstract_write_register(target, number, xlen(target), value);
} else if (number >= REG_CSR0 && number <= REG_CSR4095) {
return register_write_direct(target, number, value);
} else if (number == REG_PRIV) {
info->dcsr = set_field(info->dcsr, DCSR_PRV, value);
return ERROR_OK;
} else {
LOG_ERROR("Don't know how to write register %d", number);
return ERROR_FAIL;
return register_write_direct(target, number, value);
}
return ERROR_OK;