--- /dev/null
+/**
+ * @file gdbstub.h
+ * @author Lunaixsky ()
+ * @brief GDB Stub implementation (https://github.com/mborgerson/gdbstub).
+ * Ported for LunaixOS
+ * @version 0.1
+ * @date 2022-10-18
+ *
+ * @copyright Copyright (c) 2022 Lunaixsky & (See license below)
+ *
+ */
+
+/*
+ * Copyright (c) 2016-2022 Matt Borgerson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <hal/io.h>
+#include <klibc/string.h>
+#include <lunaix/peripheral/serial.h>
+#include <sdbg/gdbstub.h>
+
+/*****************************************************************************
+ * Types
+ ****************************************************************************/
+
+#ifndef GDBSTUB_DONT_DEFINE_STDINT_TYPES
+typedef unsigned char uint8_t;
+typedef unsigned short uint16_t;
+typedef unsigned long uint32_t;
+#endif
+
+typedef unsigned int address;
+typedef unsigned int reg;
+
+enum GDB_REGISTER
+{
+ GDB_CPU_I386_REG_EAX = 0,
+ GDB_CPU_I386_REG_ECX = 1,
+ GDB_CPU_I386_REG_EDX = 2,
+ GDB_CPU_I386_REG_EBX = 3,
+ GDB_CPU_I386_REG_ESP = 4,
+ GDB_CPU_I386_REG_EBP = 5,
+ GDB_CPU_I386_REG_ESI = 6,
+ GDB_CPU_I386_REG_EDI = 7,
+ GDB_CPU_I386_REG_PC = 8,
+ GDB_CPU_I386_REG_PS = 9,
+ GDB_CPU_I386_REG_CS = 10,
+ GDB_CPU_I386_REG_SS = 11,
+ GDB_CPU_I386_REG_DS = 12,
+ GDB_CPU_I386_REG_ES = 13,
+ GDB_CPU_I386_REG_FS = 14,
+ GDB_CPU_I386_REG_GS = 15,
+ GDB_CPU_NUM_REGISTERS = 16
+};
+
+struct gdb_state
+{
+ int signum;
+ reg registers[GDB_CPU_NUM_REGISTERS];
+};
+
+/*****************************************************************************
+ *
+ * GDB Remote Serial Protocol
+ *
+ ****************************************************************************/
+
+/*****************************************************************************
+ * Macros
+ ****************************************************************************/
+
+#define GDB_PRINT(...)
+
+#define COM_PORT SERIAL_COM1
+
+#define GDB_EOF (-1)
+
+#ifndef NULL
+#define NULL ((void*)0)
+#endif
+
+#ifndef GDB_ASSERT
+#define GDB_ASSERT(x) \
+ do { \
+ } while (0)
+#endif
+
+/*****************************************************************************
+ * Prototypes
+ ****************************************************************************/
+
+int
+gdb_main(struct gdb_state* state);
+
+/* System functions, supported by all stubs */
+void
+gdb_sys_init(void);
+int
+gdb_sys_getc(struct gdb_state* state);
+int
+gdb_sys_putchar(struct gdb_state* state, int ch);
+int
+gdb_sys_mem_readb(struct gdb_state* state, address addr, char* val);
+int
+gdb_sys_mem_writeb(struct gdb_state* state, address addr, char val);
+int
+gdb_sys_continue(struct gdb_state* state);
+int
+gdb_sys_step(struct gdb_state* state);
+
+/*****************************************************************************
+ * Types
+ ****************************************************************************/
+
+typedef int (*gdb_enc_func)(char* buf,
+ unsigned int buf_len,
+ const char* data,
+ unsigned int data_len);
+typedef int (*gdb_dec_func)(const char* buf,
+ unsigned int buf_len,
+ char* data,
+ unsigned int data_len);
+
+/*****************************************************************************
+ * Const Data
+ ****************************************************************************/
+
+static const char digits[] = "0123456789abcdef";
+
+/*****************************************************************************
+ * Prototypes
+ ****************************************************************************/
+
+/* Communication functions */
+static int
+gdb_write(struct gdb_state* state, const char* buf, unsigned int len);
+static int
+gdb_read(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ unsigned int len);
+
+/* String processing helper functions */
+static int
+gdb_strlen(const char* ch);
+static char
+gdb_get_digit(int val);
+static int
+gdb_get_val(char digit, int base);
+static int
+gdb_strtol(const char* str, unsigned int len, int base, const char** endptr);
+
+/* Packet functions */
+static int
+gdb_send_packet(struct gdb_state* state, const char* pkt, unsigned int pkt_len);
+static int
+gdb_recv_packet(struct gdb_state* state,
+ char* pkt_buf,
+ unsigned int pkt_buf_len,
+ unsigned int* pkt_len);
+static int
+gdb_checksum(const char* buf, unsigned int len);
+static int
+gdb_recv_ack(struct gdb_state* state);
+
+/* Data encoding/decoding */
+static int
+gdb_enc_hex(char* buf,
+ unsigned int buf_len,
+ const char* data,
+ unsigned int data_len);
+static int
+gdb_dec_hex(const char* buf,
+ unsigned int buf_len,
+ char* data,
+ unsigned int data_len);
+static int
+gdb_enc_bin(char* buf,
+ unsigned int buf_len,
+ const char* data,
+ unsigned int data_len);
+static int
+gdb_dec_bin(const char* buf,
+ unsigned int buf_len,
+ char* data,
+ unsigned int data_len);
+
+/* Packet creation helpers */
+static int
+gdb_send_ok_packet(struct gdb_state* state, char* buf, unsigned int buf_len);
+static int
+gdb_send_conmsg_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ const char* msg);
+static int
+gdb_send_signal_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ char signal);
+static int
+gdb_send_error_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ char error);
+
+/* Command functions */
+static int
+gdb_mem_read(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ address addr,
+ unsigned int len,
+ gdb_enc_func enc);
+static int
+gdb_mem_write(struct gdb_state* state,
+ const char* buf,
+ unsigned int buf_len,
+ address addr,
+ unsigned int len,
+ gdb_dec_func dec);
+static int
+gdb_continue(struct gdb_state* state);
+static int
+gdb_step(struct gdb_state* state);
+
+/*****************************************************************************
+ * String Processing Helper Functions
+ ****************************************************************************/
+
+/*
+ * Get null-terminated string length.
+ */
+static int
+gdb_strlen(const char* ch)
+{
+ int len;
+
+ len = 0;
+ while (*ch++) {
+ len += 1;
+ }
+
+ return len;
+}
+
+/*
+ * Get integer value for a string representation.
+ *
+ * If the string starts with + or -, it will be signed accordingly.
+ *
+ * If base == 0, the base will be determined:
+ * base 16 if the string starts with 0x or 0X,
+ * base 10 otherwise
+ *
+ * If endptr is specified, it will point to the last non-digit in the
+ * string. If there are no digits in the string, it will be set to NULL.
+ */
+static int
+gdb_strtol(const char* str, unsigned int len, int base, const char** endptr)
+{
+ unsigned int pos;
+ int sign, tmp, value, valid;
+
+ value = 0;
+ pos = 0;
+ sign = 1;
+ valid = 0;
+
+ if (endptr) {
+ *(endptr) = 0;
+ }
+
+ if (len < 1) {
+ return 0;
+ }
+
+ /* Detect negative numbers */
+ if (str[pos] == '-') {
+ sign = -1;
+ pos += 1;
+ } else if (str[pos] == '+') {
+ sign = 1;
+ pos += 1;
+ }
+
+ /* Detect '0x' hex prefix */
+ if ((pos + 2 < len) && (str[pos] == '0') &&
+ ((str[pos + 1] == 'x') || (str[pos + 1] == 'X'))) {
+ base = 16;
+ pos += 2;
+ }
+
+ if (base == 0) {
+ base = 10;
+ }
+
+ for (; (pos < len) && (str[pos] != '\x00'); pos++) {
+ tmp = gdb_get_val(str[pos], base);
+ if (tmp == GDB_EOF) {
+ break;
+ }
+
+ value = value * base + tmp;
+ valid = 1; /* At least one digit is valid */
+ }
+
+ if (!valid) {
+ return 0;
+ }
+
+ if (endptr) {
+ *endptr = str + pos;
+ }
+
+ value *= sign;
+
+ return value;
+}
+
+/*
+ * Get the corresponding ASCII hex digit character for a value.
+ */
+static char
+gdb_get_digit(int val)
+{
+ if ((val >= 0) && (val <= 0xf)) {
+ return digits[val];
+ } else {
+ return GDB_EOF;
+ }
+}
+
+/*
+ * Get the corresponding value for a ASCII digit character.
+ *
+ * Supports bases 2-16.
+ */
+static int
+gdb_get_val(char digit, int base)
+{
+ int value;
+
+ if ((digit >= '0') && (digit <= '9')) {
+ value = digit - '0';
+ } else if ((digit >= 'a') && (digit <= 'f')) {
+ value = digit - 'a' + 0xa;
+ } else if ((digit >= 'A') && (digit <= 'F')) {
+ value = digit - 'A' + 0xa;
+ } else {
+ return GDB_EOF;
+ }
+
+ return (value < base) ? value : GDB_EOF;
+}
+
+/*****************************************************************************
+ * Packet Functions
+ ****************************************************************************/
+
+/*
+ * Receive a packet acknowledgment
+ *
+ * Returns:
+ * 0 if an ACK (+) was received
+ * 1 if a NACK (-) was received
+ * GDB_EOF otherwise
+ */
+static int
+gdb_recv_ack(struct gdb_state* state)
+{
+ int response;
+
+ /* Wait for packet ack */
+ switch (response = gdb_sys_getc(state)) {
+ case '+':
+ /* Packet acknowledged */
+ return 0;
+ case '-':
+ /* Packet negative acknowledged */
+ return 1;
+ default:
+ /* Bad response! */
+ GDB_PRINT("received bad packet response: 0x%2x\n", response);
+ return GDB_EOF;
+ }
+}
+
+/*
+ * Calculate 8-bit checksum of a buffer.
+ *
+ * Returns:
+ * 8-bit checksum.
+ */
+static int
+gdb_checksum(const char* buf, unsigned int len)
+{
+ unsigned char csum;
+
+ csum = 0;
+
+ while (len--) {
+ csum += *buf++;
+ }
+
+ return csum;
+}
+
+/*
+ * Transmits a packet of data.
+ * Packets are of the form: $<packet-data>#<checksum>
+ *
+ * Returns:
+ * 0 if the packet was transmitted and acknowledged
+ * 1 if the packet was transmitted but not acknowledged
+ * GDB_EOF otherwise
+ */
+static int
+gdb_send_packet(struct gdb_state* state,
+ const char* pkt_data,
+ unsigned int pkt_len)
+{
+ char buf[3];
+ char csum;
+
+ /* Send packet start */
+ if (gdb_sys_putchar(state, '$') == GDB_EOF) {
+ return GDB_EOF;
+ }
+
+ /* Send packet data */
+ if (gdb_write(state, pkt_data, pkt_len) == GDB_EOF) {
+ return GDB_EOF;
+ }
+
+ /* Send the checksum */
+ buf[0] = '#';
+ csum = gdb_checksum(pkt_data, pkt_len);
+ if ((gdb_enc_hex(buf + 1, sizeof(buf) - 1, &csum, 1) == GDB_EOF) ||
+ (gdb_write(state, buf, sizeof(buf)) == GDB_EOF)) {
+ return GDB_EOF;
+ }
+
+ return gdb_recv_ack(state);
+}
+
+/*
+ * Receives a packet of data, assuming a 7-bit clean connection.
+ *
+ * Returns:
+ * 0 if the packet was received
+ * GDB_EOF otherwise
+ */
+static int
+gdb_recv_packet(struct gdb_state* state,
+ char* pkt_buf,
+ unsigned int pkt_buf_len,
+ unsigned int* pkt_len)
+{
+ int data;
+ char expected_csum, actual_csum;
+ char buf[2];
+
+ /* Wait for packet start */
+ actual_csum = 0;
+
+ while (1) {
+ data = gdb_sys_getc(state);
+ if (data == GDB_EOF) {
+ return GDB_EOF;
+ } else if (data == '$') {
+ /* Detected start of packet. */
+ break;
+ }
+ }
+
+ /* Read until checksum */
+ *pkt_len = 0;
+ while (1) {
+ data = gdb_sys_getc(state);
+
+ if (data == GDB_EOF) {
+ /* Error receiving character */
+ return GDB_EOF;
+ } else if (data == '#') {
+ /* End of packet */
+ break;
+ } else {
+ /* Check for space */
+ if (*pkt_len >= pkt_buf_len) {
+ GDB_PRINT("packet buffer overflow\n");
+ return GDB_EOF;
+ }
+
+ /* Store character and update checksum */
+ pkt_buf[(*pkt_len)++] = (char)data;
+ }
+ }
+
+ /* Receive the checksum */
+ if ((gdb_read(state, buf, sizeof(buf), 2) == GDB_EOF) ||
+ (gdb_dec_hex(buf, 2, &expected_csum, 1) == GDB_EOF)) {
+ return GDB_EOF;
+ }
+
+ /* Verify checksum */
+ actual_csum = gdb_checksum(pkt_buf, *pkt_len);
+ if (actual_csum != expected_csum) {
+ /* Send packet nack */
+ GDB_PRINT("received packet with bad checksum\n");
+ gdb_sys_putchar(state, '-');
+ return GDB_EOF;
+ }
+
+ /* Send packet ack */
+ gdb_sys_putchar(state, '+');
+ return 0;
+}
+
+/*****************************************************************************
+ * Data Encoding/Decoding
+ ****************************************************************************/
+
+/*
+ * Encode data to its hex-value representation in a buffer.
+ *
+ * Returns:
+ * 0+ number of bytes written to buf
+ * GDB_EOF if the buffer is too small
+ */
+static int
+gdb_enc_hex(char* buf,
+ unsigned int buf_len,
+ const char* data,
+ unsigned int data_len)
+{
+ unsigned int pos;
+
+ if (buf_len < data_len * 2) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ for (pos = 0; pos < data_len; pos++) {
+ *buf++ = gdb_get_digit((data[pos] >> 4) & 0xf);
+ *buf++ = gdb_get_digit((data[pos]) & 0xf);
+ }
+
+ return data_len * 2;
+}
+
+/*
+ * Decode data from its hex-value representation to a buffer.
+ *
+ * Returns:
+ * 0 if successful
+ * GDB_EOF if the buffer is too small
+ */
+static int
+gdb_dec_hex(const char* buf,
+ unsigned int buf_len,
+ char* data,
+ unsigned int data_len)
+{
+ unsigned int pos;
+ int tmp;
+
+ if (buf_len != data_len * 2) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ for (pos = 0; pos < data_len; pos++) {
+ /* Decode high nibble */
+ tmp = gdb_get_val(*buf++, 16);
+ if (tmp == GDB_EOF) {
+ /* Buffer contained junk. */
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+
+ data[pos] = tmp << 4;
+
+ /* Decode low nibble */
+ tmp = gdb_get_val(*buf++, 16);
+ if (tmp == GDB_EOF) {
+ /* Buffer contained junk. */
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+ data[pos] |= tmp;
+ }
+
+ return 0;
+}
+
+/*
+ * Encode data to its binary representation in a buffer.
+ *
+ * Returns:
+ * 0+ number of bytes written to buf
+ * GDB_EOF if the buffer is too small
+ */
+static int
+gdb_enc_bin(char* buf,
+ unsigned int buf_len,
+ const char* data,
+ unsigned int data_len)
+{
+ unsigned int buf_pos, data_pos;
+
+ for (buf_pos = 0, data_pos = 0; data_pos < data_len; data_pos++) {
+ if (data[data_pos] == '$' || data[data_pos] == '#' ||
+ data[data_pos] == '}' || data[data_pos] == '*') {
+ if (buf_pos + 1 >= buf_len) {
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+ buf[buf_pos++] = '}';
+ buf[buf_pos++] = data[data_pos] ^ 0x20;
+ } else {
+ if (buf_pos >= buf_len) {
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+ buf[buf_pos++] = data[data_pos];
+ }
+ }
+
+ return buf_pos;
+}
+
+/*
+ * Decode data from its bin-value representation to a buffer.
+ *
+ * Returns:
+ * 0+ if successful, number of bytes decoded
+ * GDB_EOF if the buffer is too small
+ */
+static int
+gdb_dec_bin(const char* buf,
+ unsigned int buf_len,
+ char* data,
+ unsigned int data_len)
+{
+ unsigned int buf_pos, data_pos;
+
+ for (buf_pos = 0, data_pos = 0; buf_pos < buf_len; buf_pos++) {
+ if (data_pos >= data_len) {
+ /* Output buffer overflow */
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+ if (buf[buf_pos] == '}') {
+ /* The next byte is escaped! */
+ if (buf_pos + 1 >= buf_len) {
+ /* There's an escape character, but no escaped character
+ * following the escape character. */
+ GDB_ASSERT(0);
+ return GDB_EOF;
+ }
+ buf_pos += 1;
+ data[data_pos++] = buf[buf_pos] ^ 0x20;
+ } else {
+ data[data_pos++] = buf[buf_pos];
+ }
+ }
+
+ return data_pos;
+}
+
+/*****************************************************************************
+ * Command Functions
+ ****************************************************************************/
+
+/*
+ * Read from memory and encode into buf.
+ *
+ * Returns:
+ * 0+ number of bytes written to buf
+ * GDB_EOF if the buffer is too small
+ */
+static int
+gdb_mem_read(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ address addr,
+ unsigned int len,
+ gdb_enc_func enc)
+{
+ char data[64];
+ unsigned int pos;
+
+ if (len > sizeof(data)) {
+ return GDB_EOF;
+ }
+
+ /* Read from system memory */
+ for (pos = 0; pos < len; pos++) {
+ if (gdb_sys_mem_readb(state, addr + pos, &data[pos])) {
+ /* Failed to read */
+ return GDB_EOF;
+ }
+ }
+
+ /* Encode data */
+ return enc(buf, buf_len, data, len);
+}
+
+/*
+ * Write to memory from encoded buf.
+ */
+static int
+gdb_mem_write(struct gdb_state* state,
+ const char* buf,
+ unsigned int buf_len,
+ address addr,
+ unsigned int len,
+ gdb_dec_func dec)
+{
+ char data[64];
+ unsigned int pos;
+
+ if (len > sizeof(data)) {
+ return GDB_EOF;
+ }
+
+ /* Decode data */
+ if (dec(buf, buf_len, data, len) == GDB_EOF) {
+ return GDB_EOF;
+ }
+
+ /* Write to system memory */
+ for (pos = 0; pos < len; pos++) {
+ if (gdb_sys_mem_writeb(state, addr + pos, data[pos])) {
+ /* Failed to write */
+ return GDB_EOF;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Continue program execution at PC.
+ */
+int
+gdb_continue(struct gdb_state* state)
+{
+ gdb_sys_continue(state);
+ return 0;
+}
+
+/*
+ * Step one instruction.
+ */
+int
+gdb_step(struct gdb_state* state)
+{
+ gdb_sys_step(state);
+ return 0;
+}
+
+/*****************************************************************************
+ * Packet Creation Helpers
+ ****************************************************************************/
+
+/*
+ * Send OK packet
+ */
+static int
+gdb_send_ok_packet(struct gdb_state* state, char* buf, unsigned int buf_len)
+{
+ return gdb_send_packet(state, "OK", 2);
+}
+
+/*
+ * Send a message to the debugging console (via O XX... packet)
+ */
+static int
+gdb_send_conmsg_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ const char* msg)
+{
+ unsigned int size;
+ int status;
+
+ if (buf_len < 2) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ buf[0] = 'O';
+ status = gdb_enc_hex(&buf[1], buf_len - 1, msg, gdb_strlen(msg));
+ if (status == GDB_EOF) {
+ return GDB_EOF;
+ }
+ size = 1 + status;
+ return gdb_send_packet(state, buf, size);
+}
+
+/*
+ * Send a signal packet (S AA).
+ */
+static int
+gdb_send_signal_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ char signal)
+{
+ unsigned int size;
+ int status;
+
+ if (buf_len < 4) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ buf[0] = 'S';
+ status = gdb_enc_hex(&buf[1], buf_len - 1, &signal, 1);
+ if (status == GDB_EOF) {
+ return GDB_EOF;
+ }
+ size = 1 + status;
+ return gdb_send_packet(state, buf, size);
+}
+
+/*
+ * Send a error packet (E AA).
+ */
+static int
+gdb_send_error_packet(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ char error)
+{
+ unsigned int size;
+ int status;
+
+ if (buf_len < 4) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ buf[0] = 'E';
+ status = gdb_enc_hex(&buf[1], buf_len - 1, &error, 1);
+ if (status == GDB_EOF) {
+ return GDB_EOF;
+ }
+ size = 1 + status;
+ return gdb_send_packet(state, buf, size);
+}
+
+/*****************************************************************************
+ * Communication Functions
+ ****************************************************************************/
+
+/*
+ * Write a sequence of bytes.
+ *
+ * Returns:
+ * 0 if successful
+ * GDB_EOF if failed to write all bytes
+ */
+static int
+gdb_write(struct gdb_state* state, const char* buf, unsigned int len)
+{
+ while (len--) {
+ if (gdb_sys_putchar(state, *buf++) == GDB_EOF) {
+ return GDB_EOF;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Read a sequence of bytes.
+ *
+ * Returns:
+ * 0 if successfully read len bytes
+ * GDB_EOF if failed to read all bytes
+ */
+static int
+gdb_read(struct gdb_state* state,
+ char* buf,
+ unsigned int buf_len,
+ unsigned int len)
+{
+ char c;
+
+ if (buf_len < len) {
+ /* Buffer too small */
+ return GDB_EOF;
+ }
+
+ while (len--) {
+ if ((c = gdb_sys_getc(state)) == GDB_EOF) {
+ return GDB_EOF;
+ }
+ *buf++ = c;
+ }
+
+ return 0;
+}
+
+/*****************************************************************************
+ * Main Loop
+ ****************************************************************************/
+
+/*
+ * Main debug loop. Handles commands.
+ */
+int
+gdb_main(struct gdb_state* state)
+{
+ address addr;
+ char pkt_buf[256];
+ int status;
+ unsigned int length;
+ unsigned int pkt_len;
+ const char* ptr_next;
+
+ gdb_send_signal_packet(state, pkt_buf, sizeof(pkt_buf), state->signum);
+
+ while (1) {
+ /* Receive the next packet */
+ status = gdb_recv_packet(state, pkt_buf, sizeof(pkt_buf), &pkt_len);
+ if (status == GDB_EOF) {
+ break;
+ }
+
+ if (pkt_len == 0) {
+ /* Received empty packet.. */
+ continue;
+ }
+
+ ptr_next = pkt_buf;
+
+ /*
+ * Handle one letter commands
+ */
+ switch (pkt_buf[0]) {
+
+/* Calculate remaining space in packet from ptr_next position. */
+#define token_remaining_buf (pkt_len - (ptr_next - pkt_buf))
+
+/* Expecting a seperator. If not present, go to error */
+#define token_expect_seperator(c) \
+ { \
+ if (!ptr_next || *ptr_next != c) { \
+ goto error; \
+ } else { \
+ ptr_next += 1; \
+ } \
+ }
+
+/* Expecting an integer argument. If not present, go to error */
+#define token_expect_integer_arg(arg) \
+ { \
+ arg = gdb_strtol(ptr_next, token_remaining_buf, 16, &ptr_next); \
+ if (!ptr_next) { \
+ goto error; \
+ } \
+ }
+
+ /*
+ * Read Registers
+ * Command Format: g
+ */
+ case 'g':
+ /* Encode registers */
+ status = gdb_enc_hex(pkt_buf,
+ sizeof(pkt_buf),
+ (char*)&(state->registers),
+ sizeof(state->registers));
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ pkt_len = status;
+ gdb_send_packet(state, pkt_buf, pkt_len);
+ break;
+
+ /*
+ * Write Registers
+ * Command Format: G XX...
+ */
+ case 'G':
+ status = gdb_dec_hex(pkt_buf + 1,
+ pkt_len - 1,
+ (char*)&(state->registers),
+ sizeof(state->registers));
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ gdb_send_ok_packet(state, pkt_buf, sizeof(pkt_buf));
+ break;
+
+ /*
+ * Read a Register
+ * Command Format: p n
+ */
+ case 'p':
+ ptr_next += 1;
+ token_expect_integer_arg(addr);
+
+ if (addr >= GDB_CPU_NUM_REGISTERS) {
+ goto error;
+ }
+
+ /* Read Register */
+ status = gdb_enc_hex(pkt_buf,
+ sizeof(pkt_buf),
+ (char*)&(state->registers[addr]),
+ sizeof(state->registers[addr]));
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ gdb_send_packet(state, pkt_buf, status);
+ break;
+
+ /*
+ * Write a Register
+ * Command Format: P n...=r...
+ */
+ case 'P':
+ ptr_next += 1;
+ token_expect_integer_arg(addr);
+ token_expect_seperator('=');
+
+ if (addr < GDB_CPU_NUM_REGISTERS) {
+ status = gdb_dec_hex(ptr_next,
+ token_remaining_buf,
+ (char*)&(state->registers[addr]),
+ sizeof(state->registers[addr]));
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ }
+ gdb_send_ok_packet(state, pkt_buf, sizeof(pkt_buf));
+ break;
+
+ /*
+ * Read Memory
+ * Command Format: m addr,length
+ */
+ case 'm':
+ ptr_next += 1;
+ token_expect_integer_arg(addr);
+ token_expect_seperator(',');
+ token_expect_integer_arg(length);
+
+ /* Read Memory */
+ status = gdb_mem_read(
+ state, pkt_buf, sizeof(pkt_buf), addr, length, gdb_enc_hex);
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ gdb_send_packet(state, pkt_buf, status);
+ break;
+
+ /*
+ * Write Memory
+ * Command Format: M addr,length:XX..
+ */
+ case 'M':
+ ptr_next += 1;
+ token_expect_integer_arg(addr);
+ token_expect_seperator(',');
+ token_expect_integer_arg(length);
+ token_expect_seperator(':');
+
+ /* Write Memory */
+ status = gdb_mem_write(state,
+ ptr_next,
+ token_remaining_buf,
+ addr,
+ length,
+ gdb_dec_hex);
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ gdb_send_ok_packet(state, pkt_buf, sizeof(pkt_buf));
+ break;
+
+ /*
+ * Write Memory (Binary)
+ * Command Format: X addr,length:XX..
+ */
+ case 'X':
+ ptr_next += 1;
+ token_expect_integer_arg(addr);
+ token_expect_seperator(',');
+ token_expect_integer_arg(length);
+ token_expect_seperator(':');
+
+ /* Write Memory */
+ status = gdb_mem_write(state,
+ ptr_next,
+ token_remaining_buf,
+ addr,
+ length,
+ gdb_dec_bin);
+ if (status == GDB_EOF) {
+ goto error;
+ }
+ gdb_send_ok_packet(state, pkt_buf, sizeof(pkt_buf));
+ break;
+
+ /*
+ * Continue, Kill (also treated as continue!)
+ * Command Format: c [addr]
+ */
+ case 'c':
+ case 'C':
+ case 'k':
+ gdb_continue(state);
+ return 0;
+
+ /*
+ * Single-step
+ * Command Format: s [addr]
+ */
+ case 's':
+ case 'S':
+ gdb_step(state);
+ return 0;
+
+ case '?':
+ gdb_send_signal_packet(
+ state, pkt_buf, sizeof(pkt_buf), state->signum);
+ break;
+
+ /*
+ * Unsupported Command
+ */
+ default:
+ gdb_send_packet(state, 0, 0);
+ }
+
+ continue;
+
+ error:
+ gdb_send_error_packet(state, pkt_buf, sizeof(pkt_buf), 0x00);
+
+#undef token_remaining_buf
+#undef token_expect_seperator
+#undef token_expect_integer_arg
+ }
+
+ return 0;
+}
+
+/*****************************************************************************
+ * Types
+ ****************************************************************************/
+
+struct gdb_idtr
+{
+ uint16_t len;
+ uint32_t offset;
+} __attribute__((packed));
+
+struct gdb_idt_gate
+{
+ uint16_t offset_low;
+ uint16_t segment;
+ uint16_t flags;
+ uint16_t offset_high;
+} __attribute__((packed));
+
+/*****************************************************************************
+ * Prototypes
+ ****************************************************************************/
+#define gdb_x86_io_write_8(port, val) io_outb(port, val)
+#define gdb_x86_io_read_8(port) io_inb(port)
+
+#define gdb_x86_serial_getc() serial_rx_byte(COM_PORT)
+#define gdb_x86_serial_putchar(ch) serial_tx_byte(COM_PORT, ch)
+
+#ifdef __STRICT_ANSI__
+#define asm __asm__
+#endif
+
+static struct gdb_state gdb_state;
+static volatile int start_debugging = 0;
+
+/*
+ * Debug interrupt handler.
+ */
+void
+gdbstub_loop(isr_param* param)
+{
+ /* Translate vector to signal */
+ switch (param->vector) {
+ case 1:
+ gdb_state.signum = 5;
+ break;
+ case 3:
+ gdb_state.signum = 5;
+ break;
+ default:
+ gdb_state.signum = 7;
+ }
+
+ /* Load Registers */
+ gdb_state.registers[GDB_CPU_I386_REG_EAX] = param->registers.eax;
+ gdb_state.registers[GDB_CPU_I386_REG_ECX] = param->registers.ecx;
+ gdb_state.registers[GDB_CPU_I386_REG_EDX] = param->registers.edx;
+ gdb_state.registers[GDB_CPU_I386_REG_EBX] = param->registers.ebx;
+ gdb_state.registers[GDB_CPU_I386_REG_ESP] = param->registers.esp;
+ gdb_state.registers[GDB_CPU_I386_REG_EBP] = param->registers.ebp;
+ gdb_state.registers[GDB_CPU_I386_REG_ESI] = param->registers.esi;
+ gdb_state.registers[GDB_CPU_I386_REG_EDI] = param->registers.edi;
+ gdb_state.registers[GDB_CPU_I386_REG_PC] = param->eip;
+ gdb_state.registers[GDB_CPU_I386_REG_CS] = param->cs;
+ gdb_state.registers[GDB_CPU_I386_REG_PS] = param->eflags;
+ gdb_state.registers[GDB_CPU_I386_REG_SS] = param->ss;
+ gdb_state.registers[GDB_CPU_I386_REG_DS] = param->registers.ds;
+ gdb_state.registers[GDB_CPU_I386_REG_ES] = param->registers.es;
+ gdb_state.registers[GDB_CPU_I386_REG_FS] = param->registers.fs;
+ gdb_state.registers[GDB_CPU_I386_REG_GS] = param->registers.gs;
+
+ gdb_main(&gdb_state);
+
+ /* Restore Registers */
+ param->registers.eax = gdb_state.registers[GDB_CPU_I386_REG_EAX];
+ param->registers.ecx = gdb_state.registers[GDB_CPU_I386_REG_ECX];
+ param->registers.edx = gdb_state.registers[GDB_CPU_I386_REG_EDX];
+ param->registers.ebx = gdb_state.registers[GDB_CPU_I386_REG_EBX];
+ param->registers.esp = gdb_state.registers[GDB_CPU_I386_REG_ESP];
+ param->registers.ebp = gdb_state.registers[GDB_CPU_I386_REG_EBP];
+ param->registers.esi = gdb_state.registers[GDB_CPU_I386_REG_ESI];
+ param->registers.edi = gdb_state.registers[GDB_CPU_I386_REG_EDI];
+ param->eip = gdb_state.registers[GDB_CPU_I386_REG_PC];
+ param->cs = gdb_state.registers[GDB_CPU_I386_REG_CS];
+ param->eflags = gdb_state.registers[GDB_CPU_I386_REG_PS];
+ param->ss = gdb_state.registers[GDB_CPU_I386_REG_SS];
+ param->registers.ds = gdb_state.registers[GDB_CPU_I386_REG_DS];
+ param->registers.es = gdb_state.registers[GDB_CPU_I386_REG_ES];
+ param->registers.fs = gdb_state.registers[GDB_CPU_I386_REG_FS];
+ param->registers.gs = gdb_state.registers[GDB_CPU_I386_REG_GS];
+}
+
+/*****************************************************************************
+ * Debugging System Functions
+ ****************************************************************************/
+
+/*
+ * Write one character to the debugging stream.
+ */
+int
+gdb_sys_putchar(struct gdb_state* state, int ch)
+{
+ gdb_x86_serial_putchar(ch);
+ return ch;
+}
+
+/*
+ * Read one character from the debugging stream.
+ */
+int
+gdb_sys_getc(struct gdb_state* state)
+{
+ return gdb_x86_serial_getc() & 0xff;
+}
+
+/*
+ * Read one byte from memory.
+ */
+int
+gdb_sys_mem_readb(struct gdb_state* state, address addr, char* val)
+{
+ *val = *(volatile char*)addr;
+ return 0;
+}
+
+/*
+ * Write one byte to memory.
+ */
+int
+gdb_sys_mem_writeb(struct gdb_state* state, address addr, char val)
+{
+ *(volatile char*)addr = val;
+ return 0;
+}
+
+/*
+ * Continue program execution.
+ */
+int
+gdb_sys_continue(struct gdb_state* state)
+{
+ gdb_state.registers[GDB_CPU_I386_REG_PS] &= ~(1 << 8);
+ return 0;
+}
+
+/*
+ * Single step the next instruction.
+ */
+int
+gdb_sys_step(struct gdb_state* state)
+{
+ gdb_state.registers[GDB_CPU_I386_REG_PS] |= 1 << 8;
+ return 0;
+}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / commitdiff