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Adds support for the following GDB commands:
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(1) 'g'        : read general registers
(2) 'G XX'     : write general registers
(3) 'p n '     : read the value of a specific register n
(4) 'P n..=r..': write a specific register n with value r
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@shivmgg
shivmgg committed Jul 12, 2018
1 parent b67a8c0 commit 86cef0f
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Showing 2 changed files with 157 additions and 3 deletions.
157 changes: 155 additions & 2 deletions src/libosd/gdbserver.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
* limitations under the License.
*/

#include <osd/cl_cdm.h>
#include <osd/gdbserver.h>
#include <osd/module.h>
#include <osd/osd.h>
Expand All @@ -39,6 +40,8 @@
struct osd_gdbserver_ctx {
struct osd_hostmod_ctx *hostmod_ctx;
struct osd_log_ctx *log_ctx;
struct osd_cdm_desc cdm_desc;
uint16_t cdm_di_addr;
int fd;
char *name;
char *port;
Expand All @@ -53,21 +56,25 @@ struct osd_gdbserver_ctx {
API_EXPORT
osd_result osd_gdbserver_new(struct osd_gdbserver_ctx **ctx,
struct osd_log_ctx *log_ctx,
const char *host_controller_address)
const char *host_controller_address,
uint16_t cdm_di_addr)
{
osd_result rv;

struct osd_gdbserver_ctx *c = calloc(1, sizeof(struct osd_gdbserver_ctx));
assert(c);

c->log_ctx = log_ctx;
c->cdm_di_addr = cdm_di_addr;

struct osd_hostmod_ctx *hostmod_ctx;
rv = osd_hostmod_new(&hostmod_ctx, log_ctx, host_controller_address, NULL,
NULL);
assert(OSD_SUCCEEDED(rv));
c->hostmod_ctx = hostmod_ctx;

// c->cdm_desc = cdm_desc;

*ctx = c;

return OSD_OK;
Expand Down Expand Up @@ -298,7 +305,7 @@ bool validate_rsp_packet(char *packet_buffer, int packet_len,
}

static osd_result receive_rsp_packet(struct osd_gdbserver_ctx *ctx,
int *packet_data_len, char *packet_data)
char *packet_data, int *packet_data_len)
{
int packet_char;
osd_result rv;
Expand Down Expand Up @@ -375,3 +382,149 @@ static osd_result send_rsp_packet(struct osd_gdbserver_ctx *ctx,
}
}
}

static osd_result gdb_read_general_registers_cmd(struct osd_gdbserver_ctx *ctx,
char *packet_buffer,
int packet_len)
{
osd_result rv;
// SPR register address mapped as GPR0 in OR1K
// GROUP 0 REG_NUM 1024
uint16_t reg_addr = 0x400;

rv =
osd_cl_cdm_get_desc(ctx->hostmod_ctx, ctx->cdm_di_addr, &ctx->cdm_desc);
if (OSD_FAILED(rv)) {
return rv;
}

int core_reg_len = ctx->cdm_desc.core_data_width;
size_t reg_read_result[32];
// + 1 for null character
// used for storing the read register value of all the GPRs
char *reg_packet = malloc((core_reg_len / 8) * 32 + 1);

// read the value of each GPR from the CPU core and
// store it in the register packet
for (int i = 0; i < 32; i++) {
rv = cl_cdm_cpureg_read(ctx->hostmod_ctx, &ctx->cdm_desc,
&reg_read_result[i], reg_addr + i, 0);
if (OSD_FAILED(rv)) {
return rv;
}

char *reg_val = malloc((core_reg_len / 8) + 1);
sprintf(reg_val, "%02lx", reg_read_result[i]);
strcat(reg_packet, reg_val);
free(reg_val);
}

rv = send_rsp_packet(ctx, reg_packet, (core_reg_len / 8) * 32 + 1);
if (OSD_FAILED(rv)) {
return rv;
}

free(reg_packet);

return OSD_OK;
}

static osd_result gdb_write_general_registers_cmd(struct osd_gdbserver_ctx *ctx,
char *packet, int packet_len)
{
osd_result rv;
rv =
osd_cl_cdm_get_desc(ctx->hostmod_ctx, ctx->cdm_di_addr, &ctx->cdm_desc);
if (OSD_FAILED(rv)) {
return rv;
}

// increment by 1 to skip initial char 'G'
packet++;
// SPR register address mapped as GPR0 in OR1K
// GROUP 0 REG_NUM 1024
uint16_t reg_addr = 0x400;
int core_reg_len = ctx->cdm_desc.core_data_width;

// write the value of each GPR in the CPU core
for (int i = 0; i < 32; i++) {
char cur_reg_val[core_reg_len / 4 + 1];
for (int j = 0; j < core_reg_len / 4; j++) {
cur_reg_val[j] = packet[i * core_reg_len + j];
}

cur_reg_val[core_reg_len / 4] = '\0';
size_t reg_val = strtoul(cur_reg_val, NULL, 16);
rv = cl_cdm_cpureg_write(ctx->hostmod_ctx, &ctx->cdm_desc, &reg_val,
reg_addr + i, 0);
if (OSD_FAILED(rv)) {
return rv;
}
}

rv = send_rsp_packet(ctx, "OK", 2);
if (OSD_FAILED(rv)) {
return rv;
}

return OSD_OK;
}

static osd_result gdb_read_register_cmd(struct osd_gdbserver_ctx *ctx,
char *packet, int packet_len)
{
osd_result rv;
uint16_t reg_addr = strtoul(packet + 1, NULL, 16);

rv =
osd_cl_cdm_get_desc(ctx->hostmod_ctx, ctx->cdm_di_addr, &ctx->cdm_desc);
if (OSD_FAILED(rv)) {
return rv;
}

int core_reg_len = ctx->cdm_desc.core_data_width;
size_t reg_read_result;
rv = cl_cdm_cpureg_read(ctx->hostmod_ctx, &ctx->cdm_desc, &reg_read_result,
reg_addr, 0);
if (OSD_FAILED(rv)) {
return rv;
}

char *reg_val = malloc(core_reg_len / 8 + 1);
sprintf(reg_val, "%02lx", reg_read_result);
rv = send_rsp_packet(ctx, reg_val, core_reg_len / 8 + 1);
if (OSD_FAILED(rv)) {
return rv;
}

free(reg_val);

return OSD_OK;
}

static osd_result gdb_write_register_cmd(struct osd_gdbserver_ctx *ctx,
char *packet, int packet_len)
{
osd_result rv;
char *equal_separator;
uint16_t reg_addr = strtoul(packet + 1, &equal_separator, 16);
rv =
osd_cl_cdm_get_desc(ctx->hostmod_ctx, ctx->cdm_di_addr, &ctx->cdm_desc);
if (OSD_FAILED(rv)) {
return rv;
}

size_t reg_val = strtoul(equal_separator + 1, NULL, 16);
rv = cl_cdm_cpureg_write(ctx->hostmod_ctx, &ctx->cdm_desc, &reg_val,
reg_addr, 0);
if (OSD_FAILED(rv)) {
return rv;
}

rv = send_rsp_packet(ctx, "OK", 2);
if (OSD_FAILED(rv)) {
return rv;
}

return OSD_OK;
}
3 changes: 2 additions & 1 deletion src/libosd/include/osd/gdbserver.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,7 +49,8 @@ struct osd_gdbserver_ctx;
*/
osd_result osd_gdbserver_new(struct osd_gdbserver_ctx **ctx,
struct osd_log_ctx *log_ctx,
const char *host_controller_address);
const char *host_controller_address,
uint16_t cdm_di_addr);

/**
* Connect GDB server to the host controller followed by GDB
Expand Down

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