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RIOT/cpu/esp8266/vendor/esp-gdbstub/gdbstub.c
Marian Buschsieweke 35d46e6dc3
cpu/esp: Use API to access sched internals
Replace access to `sched_active_task` and `sched_active_pid` with calls to
`thread_getpid()` and `thread_get_active()`.
2020-08-17 14:05:05 +02:00

988 lines
29 KiB
C

/******************************************************************************
* Copyright 2015 Espressif Systems
*
* Description: A stub to make the ESP8266 debuggable by GDB over the serial
* port.
*
* License: ESPRESSIF MIT License
*******************************************************************************/
#include <signal.h>
#include <string.h>
#include "eagle_soc.h"
#include "esp_attr.h"
#include "esp_common.h"
#include "periph/uart.h"
#include "rom/ets_sys.h"
#include "sdk/sdk.h"
#include "xtensa/corebits.h"
#include "gdbstub.h"
#include "gdbstub-exc.h"
#include "gdbstub-entry.h"
#include "gdbstub-cfg.h"
#if GDBSTUB_CTRLC_BREAK
#include "isrpipe.h"
#include "sched.h"
#include "thread.h"
#endif
#if GDBSTUB_BREAK_ON_INIT
#include "irq.h"
#endif
#define ets_isr_t xt_handler
/* register frame structure as used by gdbstub */
typedef struct {
XtExcFrame exc_frame; /* exception frame as used by exception handlers */
XtExcFrameGdb exc_frame_gdb; /* gdb exception frame extensions */
} gdb_exception_frame_t;
/*
* Defines some things that aren't in the include files
*/
#define EXCEPTION_GDB_SP_OFFSET 0x100
/* We need some UART register defines. */
#define ETS_UART_INUM 5
#define REG_UART_BASE( i ) (0x60000000+(i)*0xf00)
#define UART_STATUS( i ) (REG_UART_BASE( i ) + 0x1C)
#define UART_RXFIFO_CNT 0x000000FF
#define UART_RXFIFO_CNT_S 0
#define UART_TXFIFO_CNT 0x000000FF
#define UART_TXFIFO_CNT_S 16
#define UART_FIFO( i ) (REG_UART_BASE( i ) + 0x0)
#define UART_INT_ENA(i) (REG_UART_BASE(i) + 0xC)
#define UART_INT_CLR(i) (REG_UART_BASE(i) + 0x10)
#define UART_RXFIFO_TOUT_INT_ENA (BIT(8))
#define UART_RXFIFO_FULL_INT_ENA (BIT(0))
#define UART_RXFIFO_TOUT_INT_CLR (BIT(8))
#define UART_RXFIFO_FULL_INT_CLR (BIT(0))
/*
* Length of buffer used to reserve GDB commands. Has to be at least able to
* fit the G command, which implies a minimum size of about 190 bytes.
*/
#define PBUFLEN 256
/* Length of gdb stdout buffer, for console redirection */
#define OBUFLEN 256
/*
* The asm stub saves the Xtensa registers here when a debugging exception
* happens.
*/
gdb_exception_frame_t gdbstub_regs;
#if GDBSTUB_USE_OWN_STACK
/* This is the debugging exception stack. */
int gdbstub_exceptionStack[GDBSTUB_STACK_SIZE / sizeof(int)];
#endif
static unsigned char cmd[PBUFLEN]; /* GDB command input buffer */
static char chsum; /* Running checksum of the out put packet */
#if GDBSTUB_REDIRECT_CONSOLE_OUTPUT
static unsigned char obuf[OBUFLEN]; /* GDB stdout buffer */
static int obufpos=0; /* Current position in the buffer */
#endif
static int32_t singleStepPs = -1; /* Stores ps when single-stepping */
/* instruction. -1 when not in use. */
static bool gdbstub_initialized = false;
/* Receive a char from the UART. Uses polling and feeds the watchdog. */
static int ATTR_GDBFN gdbRecvChar(void)
{
int i;
while (((READ_PERI_REG(UART_STATUS(0)) >> UART_RXFIFO_CNT_S) & UART_RXFIFO_CNT)==0) {
WDT_FEED();
}
i = READ_PERI_REG(UART_FIFO(0));
return i;
}
/* Send a char to the UART. */
static void ATTR_GDBFN gdbSendChar(char c)
{
uart_write(UART_DEV(0), (const uint8_t *)&c, 1);
}
/* Send the start of a packet; reset checksum calculation. */
static void ATTR_GDBFN gdbPacketStart(void)
{
chsum=0;
gdbSendChar('$');
}
/* Send a char as part of a packet */
static void ATTR_GDBFN gdbPacketChar(char c)
{
if (c == '#' || c == '$' || c == '}' || c == '*') {
gdbSendChar('}');
gdbSendChar(c ^ 0x20);
chsum += (c ^ 0x20) +'}';
}
else {
gdbSendChar(c);
chsum += c;
}
}
/* Send a string as part of a packet */
static void ATTR_GDBFN gdbPacketStr(char *c)
{
while (*c != 0) {
gdbPacketChar(*c);
c++;
}
}
/* Send a hex val as part of a packet. 'bits'/4 dictates the number of hex chars sent. */
static void ATTR_GDBFN gdbPacketHex(int val, int bits)
{
char hexChars[]="0123456789abcdef";
int i;
for (i = bits; i > 0; i -= 4) {
gdbPacketChar(hexChars[(val >> (i-4)) & 0xf]);
}
}
/* Finish sending a packet. */
static void ATTR_GDBFN gdbPacketEnd(void)
{
gdbSendChar('#');
gdbPacketHex(chsum, 8);
}
/*
* Error states used by the routines that grab stuff from the incoming
* gdb packet
*/
#define ST_ENDPACKET -1
#define ST_ERR -2
#define ST_OK -3
#define ST_CONT -4
/*
* Grab a hex value from the gdb packet. Ptr will get positioned on the end
* of the hex string, as far as the routine has read into it. Bits/4 indicates
* the max amount of hex chars it gobbles up. Bits can be -1 to eat up as much
* hex chars as possible.
*/
static long ATTR_GDBFN gdbGetHexVal(unsigned char **ptr, int bits)
{
int i;
int no = bits/4;
unsigned int v = 0;
if (bits == -1) {
no=64;
}
for (i = 0; i < no; i++) {
char c;
c = **ptr;
(*ptr)++;
if (c >= '0' && c <= '9') {
v <<= 4;
v |= (c - '0');
}
else if (c >= 'A' && c <= 'F') {
v <<= 4;
v |= (c - 'A') + 10;
}
else if (c >= 'a' && c <= 'f') {
v <<= 4;
v |= (c - 'a') + 10;
}
else if (c == '#') {
if (bits == -1) {
(*ptr)--;
return v;
}
return ST_ENDPACKET;
}
else {
if (bits == -1) {
(*ptr)--;
return v;
}
return ST_ERR;
}
}
return v;
}
/* Swap an int into the form gdb wants it */
static int ATTR_GDBFN iswap(int i)
{
int r;
r = ((i >> 24) & 0xff);
r |= ((i >> 16) & 0xff) << 8;
r |= ((i >> 8) & 0xff) << 16;
r |= ((i >> 0) & 0xff) << 24;
return r;
}
/* Read a byte from the ESP8266 memory. */
static unsigned char ATTR_GDBFN readbyte(unsigned int p)
{
int *i = (int*)(p & (~3));
if (p < 0x20000000 || p >= 0x60000000) {
return -1;
}
return *i >> ((p & 3) * 8);
}
/* Write a byte to the ESP8266 memory. */
static void ATTR_GDBFN writeByte(unsigned int p, unsigned char d)
{
int *i = (int*)(p & (~3));
if (p < 0x20000000 || p >= 0x60000000) {
return;
}
if ((p & 3) == 0) *i = (*i & 0xffffff00) | (d << 0);
if ((p & 3) == 1) *i = (*i & 0xffff00ff) | (d << 8);
if ((p & 3) == 2) *i = (*i & 0xff00ffff) | (d << 16);
if ((p & 3) == 3) *i = (*i & 0x00ffffff) | (d << 24);
}
/* Returns 1 if it makes sense to write to addr p */
static int ATTR_GDBFN validWrAddr(int p)
{
return ((p >= 0x3ff00000 && p < 0x40000000) ||
(p >= 0x40100000 && p < 0x40140000) ||
(p >= 0x60000000 && p < 0x60002000)) ? 1 : 0;
}
/*
* Register file in the format lx106 gdb port expects it.
* Inspired by gdb/regformats/reg-xtensa.dat from
* https://github.com/jcmvbkbc/crosstool-NG/blob/lx106-g%2B%2B/overlays/xtensa_lx106.tar
* As decoded by Cesanta.
*/
struct regfile
{
uint32_t a[16];
uint32_t pc;
uint32_t sar;
uint32_t litbase;
uint32_t sr176;
uint32_t sr208;
uint32_t ps;
};
/* Send the reason execution is stopped to GDB. */
static void ATTR_GDBFN sendReason(void)
{
#if 0
char *reason=""; /* default */
#endif
gdbPacketStart();
gdbPacketChar('T');
if (gdbstub_regs.exc_frame_gdb.reason == 0xff) {
gdbPacketHex(2, 8); /* sigint */
}
else if (gdbstub_regs.exc_frame_gdb.reason & 0x80)
{
/* exception-to-signal mapping */
char exceptionSignal[] = {
SIGILL, /* IllegalInstructionCause >> SIGILL - 4 */
SIGUSR2, /* SyscallCause >> SIGUSR2 - 31 */
SIGSEGV, /* InstructionFetchErrorCause >> SIGSEGV - 11 */
SIGSEGV, /* LoadStoreErrorCause >> SIGSEGV - 11 */
SIGINT, /* Level1InterruptCause >> SIGINT - 2 */
SIGABRT, /* AllocaCause >> SIGABRT - 6 */
SIGFPE, /* IntegerDivideByZeroCause >> SIGFPE - 8 */
0, /* not used >> 0 */
SIGABRT, /* PrivilegedCause >> SIGABRT - 6 */
SIGEMT, /* LoadStoreAlignmentCause >> SIGEMT - 7 */
0, /* not used >> 0 */
0, /* not used >> 0 */
SIGEMT, /* InstrPIFDataErrorCause >> SIGEMT - 7 */
SIGEMT, /* LoadStorePIFDataErrorCause >> SIGEMT - 7 */
SIGEMT, /* InstrPIFAddrErrorCause >> SIGEMT - 7 */
SIGEMT /* LoadStorePIFAddrErrorCause >> SIGEMT - 7 */
};
unsigned int i = 0;
/* We stopped because of an exception. */
/* Convert exception code to a signal number and send it. */
i = gdbstub_regs.exc_frame_gdb.reason & 0x7f;
if (i < sizeof(exceptionSignal))
gdbPacketHex(exceptionSignal[i], 8);
else
gdbPacketHex(SIGSEGV, 8);
}
else
{
/* We stopped because of a debugging exception. */
gdbPacketHex(5, 8); /* sigtrap */
/* Current Xtensa GDB versions don't seem to request this, so let's leave it off. */
#if 0
if (gdbstub_regs.exc_frame_gdb.reason&(1 << 0)) reason="break";
if (gdbstub_regs.exc_frame_gdb.reason&(1 << 1)) reason="hwbreak";
if (gdbstub_regs.exc_frame_gdb.reason&(1 << 2)) reason="watch";
if (gdbstub_regs.exc_frame_gdb.reason&(1 << 3)) reason="swbreak";
if (gdbstub_regs.exc_frame_gdb.reason&(1 << 4)) reason="swbreak";
gdbPacketStr(reason);
gdbPacketChar(':');
/* TODO: watch: send address */
#endif
}
gdbPacketEnd();
}
/*
* Handle a command as received from GDB.
*/
static int ATTR_GDBFN gdbHandleCommand(unsigned char *cmd, int len)
{
int i, j, k;
unsigned char *data = cmd + 1;
if (cmd[0] == 'g') {
/*
* send all registers to gdb
* format corresponds to struct regfile
*/
unsigned *ar = (unsigned*)&gdbstub_regs.exc_frame.a0; /* a register array */
gdbPacketStart();
for (int i = 0; i < 16; i++) {
gdbPacketHex(iswap(ar[i]), 32);
}
gdbPacketHex(iswap(gdbstub_regs.exc_frame.pc), 32);
gdbPacketHex(iswap(gdbstub_regs.exc_frame.sar), 32);
gdbPacketHex(iswap(gdbstub_regs.exc_frame_gdb.litbase), 32);
gdbPacketHex(iswap(gdbstub_regs.exc_frame_gdb.sr176), 32);
gdbPacketHex(0, 32); /* sr208 is not sent */
gdbPacketHex(iswap(gdbstub_regs.exc_frame.ps), 32);
gdbPacketEnd();
}
else if (cmd[0]=='G') {
/*
* receive content for all registers from gdb
* format corresponds to struct regfile
*/
unsigned *ar = (unsigned*)&gdbstub_regs.exc_frame.a0; /* a register array */
gdbPacketStart();
for (int i = 0; i < 16; i++) {
ar[i] = iswap(gdbGetHexVal(&data, 32));
}
gdbstub_regs.exc_frame.pc = iswap(gdbGetHexVal(&data, 32));
gdbstub_regs.exc_frame.sar = iswap(gdbGetHexVal(&data, 32));
gdbstub_regs.exc_frame_gdb.litbase = iswap(gdbGetHexVal(&data, 32));
gdbstub_regs.exc_frame_gdb.sr176 = iswap(gdbGetHexVal(&data, 32));
gdbGetHexVal(&data, 32);
gdbstub_regs.exc_frame.ps = iswap(gdbGetHexVal(&data, 32));
gdbPacketStart();
gdbPacketStr("OK");
gdbPacketEnd();
}
else if (cmd[0]=='m') {
/* read memory to gdb */
i = gdbGetHexVal(&data, -1);
data++;
j = gdbGetHexVal(&data, -1);
gdbPacketStart();
for (k = 0; k < j; k++) {
gdbPacketHex(readbyte(i++), 8);
}
gdbPacketEnd();
}
else if (cmd[0] == 'M') {
/* write memory from gdb */
i = gdbGetHexVal(&data, -1); /* addr */
data++; /* skip */
j = gdbGetHexVal(&data, -1); /* length */
data++; /* skip */
if (validWrAddr(i) && validWrAddr(i+j)) {
for (k = 0; k<j; k++) {
writeByte(i, gdbGetHexVal(&data, 8));
i++;
}
/*
* Make sure caches are up-to-date.
* Procedure according to Xtensa ISA document, ISYNC inst desc.
*/
__asm__ volatile("isync\nisync\n");
gdbPacketStart();
gdbPacketStr("OK");
gdbPacketEnd();
}
else {
/* Trying to do a software breakpoint on a flash proc, perhaps? */
gdbPacketStart();
gdbPacketStr("E01");
gdbPacketEnd();
}
}
else if (cmd[0] == '?') {
/* Reply with stop reason */
sendReason();
}
#if 0
else if (strncmp(cmd, "vCont?", 6) == 0) {
gdbPacketStart();
gdbPacketStr("vCont;c;s");
gdbPacketEnd();
}
#endif
else if (strncmp((char*)cmd, "vCont;c", 7) == 0 || cmd[0] == 'c') {
/* continue execution */
return ST_CONT;
}
else if (strncmp((char*)cmd, "vCont;s", 7) == 0 || cmd[0] == 's') {
/*
* single-step instruction
* Single-stepping can go wrong if an interrupt is pending, especially
* when it is e.g. a task switch: the ICOUNT register will overflow
* in the task switch code. That is why we disable interupts when
* doing single-instruction stepping.
*/
singleStepPs = gdbstub_regs.exc_frame.ps;
gdbstub_regs.exc_frame.ps = (gdbstub_regs.exc_frame.ps & ~0xf) | (XCHAL_DEBUGLEVEL - 1);
gdbstub_icount_ena_single_step();
return ST_CONT;
}
else if (cmd[0] == 'q') {
/* Extended query */
if (strncmp((char*)&cmd[1], "Supported", 9) == 0) {
/* Capabilities query */
gdbPacketStart();
gdbPacketStr("swbreak+;hwbreak+;PacketSize=255");
gdbPacketEnd();
}
else {
/* other queries are not supported */
gdbPacketStart();
gdbPacketEnd();
return ST_ERR;
}
}
else if (cmd[0] == 'Z') {
/* Set hardware break/watchpoint. */
data += 2; /* skip 'x,' */
i = gdbGetHexVal(&data, -1);
data++; /* skip ',' */
j = gdbGetHexVal(&data, -1);
gdbPacketStart();
if (cmd[1] == '1') {
/* Set breakpoint */
if (gdbstub_set_hw_breakpoint(i, j)) {
gdbPacketStr("OK");
}
else {
gdbPacketStr("E01");
}
}
else if (cmd[1] == '2' || cmd[1] == '3' || cmd[1] == '4') {
/* Set watchpoint */
int access = 0;
int mask = 0;
switch (cmd[1]) {
case '2': access=2; break; /* write */
case '3': access=1; break; /* read */
case '4': access=4; break; /* access */
default: access = 0;
}
switch (j) {
case 1: mask = 0x3F; break;
case 2: mask = 0x3E; break;
case 4: mask = 0x3C; break;
case 8: mask = 0x38; break;
case 16: mask = 0x30; break;
case 32: mask = 0x20; break;
case 64: mask = 0x00; break;
default: mask = 0;
}
if (mask!=0 && gdbstub_set_hw_watchpoint(i, mask, access)) {
gdbPacketStr("OK");
}
else {
gdbPacketStr("E01");
}
}
gdbPacketEnd();
}
else if (cmd[0] == 'z') {
/* Clear hardware break/watchpoint */
data += 2; /* skip 'x,' */
i = gdbGetHexVal(&data, -1);
data++; /* skip ',' */
j = gdbGetHexVal(&data, -1);
gdbPacketStart();
if (cmd[1] == '1') {
/* hardware breakpoint */
if (gdbstub_del_hw_breakpoint(i)) {
gdbPacketStr("OK");
}
else {
gdbPacketStr("E01");
}
}
else if (cmd[1] == '2' || cmd[1] == '3' || cmd[1] == '4') {
/* hardware watchpoint */
if (gdbstub_del_hw_watchpoint(i)) {
gdbPacketStr("OK");
}
else {
gdbPacketStr("E01");
}
}
gdbPacketEnd();
}
else {
/* We don't recognize or support whatever GDB just sent us. */
gdbPacketStart();
gdbPacketEnd();
return ST_ERR;
}
return ST_OK;
}
/*
* Lower layer: grab a command packet and check the checksum
* Calls gdbHandleCommand on the packet if the checksum is OK
* Returns ST_OK on success,
* ST_ERR when checksum fails,
* a character if it is received instead of the GDB packet start char.
*/
static bool _gdbstub_in_rcv_packet = false;
static int ATTR_GDBFN gdbReadCommand(void)
{
unsigned char c;
unsigned char chsum = 0, rchsum;
unsigned char sentchs[2];
int p = 0;
unsigned char *ptr;
c = gdbRecvChar();
if (c != '$') {
return c;
}
while(1) {
c = gdbRecvChar();
if (c == '#') { /* end of packet, checksum follows, break the loop */
cmd[p] = 0;
break;
}
chsum += c;
if (c == '$') { /* restart packet? */
_gdbstub_in_rcv_packet = true;
chsum = 0;
p = 0;
continue;
}
if (c == '}') { /* escape the next char */
c = gdbRecvChar();
chsum += c;
c ^= 0x20;
}
cmd[p++] = c;
if (p >= PBUFLEN) {
return ST_ERR;
}
}
/* # has been received. Get the received chsum. */
sentchs[0] = gdbRecvChar();
sentchs[1] = gdbRecvChar();
/* check the received checksum */
ptr = sentchs;
rchsum = gdbGetHexVal(&ptr, 8);
if (rchsum != chsum) {
/* wrong checksum, request retransmission */
gdbSendChar('-');
_gdbstub_in_rcv_packet = false;
return ST_ERR;
}
/* ack the package and handle the command */
gdbSendChar('+');
_gdbstub_in_rcv_packet = false;
return gdbHandleCommand(cmd, p);
}
/* get the value of one of an A registers */
static unsigned int ATTR_GDBFN getaregval(int reg)
{
assert(reg >= 0 && reg < 16);
unsigned *ar = (unsigned*)&gdbstub_regs.exc_frame.a0;
return ar[reg];
}
/* set the value of one of an A registers */
static void ATTR_GDBFN setaregval(int reg, unsigned int val)
{
ets_printf("%x -> %x\n", val, reg);
assert(reg >= 0 && reg < 16);
unsigned *ar = (unsigned*)&gdbstub_regs.exc_frame.a0;
ar[reg] = val;
}
/* Emulate the l32i/s32i instruction we're stopped at. */
static void ATTR_GDBFN emulLdSt(void)
{
unsigned char i0 = readbyte(gdbstub_regs.exc_frame.pc);
unsigned char i1 = readbyte(gdbstub_regs.exc_frame.pc+1);
unsigned char i2 = readbyte(gdbstub_regs.exc_frame.pc+2);
int *p;
if ((i0 & 0xf) == 2 && (i1 & 0xf0) == 0x20) {
/* l32i */
p = (int*)getaregval(i1 & 0xf) + (i2 * 4);
setaregval(i0 >> 4, *p);
gdbstub_regs.exc_frame.pc += 3;
}
else if ((i0 & 0xf) == 0x8) {
/* l32i.n */
p = (int*)getaregval(i1 & 0xf) + ((i1 >> 4) * 4);
setaregval(i0 >> 4, *p);
gdbstub_regs.exc_frame.pc += 2;
}
else if ((i0 & 0xf) == 2 && (i1 & 0xf0) == 0x60) {
/* s32i */
p = (int*)getaregval(i1 & 0xf) + (i2*4);
*p = getaregval(i0 >> 4);
gdbstub_regs.exc_frame.pc += 3;
}
else if ((i0 & 0xf) == 0x9) {
/* s32i.n */
p = (int*)getaregval(i1 & 0xf) + ((i1 >> 4) * 4);
*p = getaregval(i0 >> 4);
gdbstub_regs.exc_frame.pc += 2;
}
else {
ets_printf("GDBSTUB: No l32i/s32i instruction: %x %x %x. Huh?", i2, i1, i0);
}
}
void gdbstub_print_regs(void)
{
ets_printf("pc : %08x\t", gdbstub_regs.exc_frame.pc);
ets_printf("ps : %08x\t", gdbstub_regs.exc_frame.ps);
ets_printf("exccause: %08x\t", gdbstub_regs.exc_frame.exccause);
ets_printf("excvaddr: %08x\n", gdbstub_regs.exc_frame.excvaddr);
ets_printf("a0 : %08x\t", gdbstub_regs.exc_frame.a0);
ets_printf("a1 : %08x\t", gdbstub_regs.exc_frame.a1);
ets_printf("a2 : %08x\t", gdbstub_regs.exc_frame.a2);
ets_printf("a3 : %08x\n", gdbstub_regs.exc_frame.a3);
ets_printf("a4 : %08x\t", gdbstub_regs.exc_frame.a4);
ets_printf("a5 : %08x\t", gdbstub_regs.exc_frame.a5);
ets_printf("a6 : %08x\t", gdbstub_regs.exc_frame.a6);
ets_printf("a7 : %08x\n", gdbstub_regs.exc_frame.a7);
ets_printf("a8 : %08x\t", gdbstub_regs.exc_frame.a8);
ets_printf("a9 : %08x\t", gdbstub_regs.exc_frame.a9);
ets_printf("a10 : %08x\t", gdbstub_regs.exc_frame.a10);
ets_printf("a11 : %08x\n", gdbstub_regs.exc_frame.a11);
ets_printf("a12 : %08x\t", gdbstub_regs.exc_frame.a12);
ets_printf("a13 : %08x\t", gdbstub_regs.exc_frame.a13);
ets_printf("a14 : %08x\t", gdbstub_regs.exc_frame.a14);
ets_printf("a15 : %08x\n", gdbstub_regs.exc_frame.a15);
#if XCHAL_HAVE_LOOPS
ets_printf("lbeg : %08x\t", gdbstub_regs.exc_frame.lbeg);
ets_printf("lend : %08x\t", gdbstub_regs.exc_frame.lend);
ets_printf("lcount : %08x\n", gdbstub_regs.exc_frame.lcount);
#endif /* XCHAL_HAVE_LOOPS */
#ifdef XT_USE_SWPRI
ets_printf("vpri : %08x\n", gdbstub_regs.exc_frame.vpri);
#endif
#ifdef XT_USE_OVLY
#ifdef XT_USE_SWPRI
ets_printf("ovly : %08x\n", gdbstub_regs.exc_frame.ovly);
#endif
#endif
ets_printf("litbase : %08x\t", gdbstub_regs.exc_frame_gdb.litbase);
ets_printf("sr176 : %08x\t", gdbstub_regs.exc_frame_gdb.sr176);
ets_printf("sr208 : %08x\t", gdbstub_regs.exc_frame_gdb.sr208);
ets_printf("reason : %08x\n", gdbstub_regs.exc_frame_gdb.reason);
}
/*
* We just caught a debug exception and need to handle it. This is called
* from an assembly routine in gdbstub-entry.S
*/
void ATTR_GDBFN gdbstub_handle_debug_exception(void)
{
ets_wdt_disable();
if (singleStepPs != -1)
{
/*
* We come here after single-stepping an instruction. Interrupts are
* disabled for the single step. Re-enable them here.
*/
gdbstub_regs.exc_frame.ps = (gdbstub_regs.exc_frame.ps & ~0xf) | (singleStepPs & 0xf);
singleStepPs = -1;
}
sendReason();
while (gdbReadCommand() != ST_CONT) { }
if ((gdbstub_regs.exc_frame_gdb.reason & 0x84) == 0x4)
{
/*
* We stopped due to a watchpoint. We can't re-execute the current
* instruction because it will happily re-trigger the same watchpoint,
* so we emulate it while we're still in debugger space.
*/
emulLdSt();
}
else if ((gdbstub_regs.exc_frame_gdb.reason & 0x88) == 0x8) {
/*
* We stopped due to a BREAK instruction. Skip over it. Check the
* instruction first; gdb may have replaced it with the
* original instruction if it's one of the breakpoints it set.
*/
if ((readbyte(gdbstub_regs.exc_frame.pc + 2) & 0xff) == 0 &&
(readbyte(gdbstub_regs.exc_frame.pc + 1) & 0xf0) == 0x40 &&
(readbyte(gdbstub_regs.exc_frame.pc) & 0x0f) == 0x00) {
gdbstub_regs.exc_frame.pc += 3;
}
}
else if ((gdbstub_regs.exc_frame_gdb.reason & 0x90) == 0x10) {
/*
* We stopped due to a BREAK.N instruction. Skip over it, after
* making sure the instruction actually is a BREAK.N
*/
if ((readbyte(gdbstub_regs.exc_frame.pc+1) & 0xf0) == 0xf0 &&
(readbyte(gdbstub_regs.exc_frame.pc) & 0xff) == 0x2d) {
gdbstub_regs.exc_frame.pc+=3;
}
}
ets_wdt_enable();
}
static void ATTR_GDBFN gdb_exception_handler(XtExcFrame *frame)
{
assert(frame != NULL);
ets_printf("GDB entry after exception @%08x\n", frame->pc);
/*
* On entry, registers ps, pc, a0...a15, sar, lbeg, lend, lcount, vpri,
* ovly have been already saved by _xt_user_exc including _xt_context_save
*/
/* copy the registers the Xtensa exception handler did save to gdbstub_regs */
ets_memcpy(&gdbstub_regs.exc_frame, frame, sizeof(XtExcFrame));
/* save the extra registers the exception vectors doesn't save */
gdbstub_save_extra_sfrs_for_exception();
gdbstub_regs.exc_frame_gdb.reason |= 0x80; /* mark as an exception reason */
ets_wdt_disable();
sendReason();
while (gdbReadCommand() != ST_CONT) { }
ets_wdt_enable();
/* Copy changed registers back to the standard exception frame. */
ets_memcpy(frame, &gdbstub_regs.exc_frame, sizeof(XtExcFrame));
}
#if GDBSTUB_REDIRECT_CONSOLE_OUTPUT
/*
* The following functions realize the communication with the gdb for console
* output. Each *printf function finally calls ets_printf which in turn calls
* ets_putc. Instead of spitting out the characters directly, the characters
* are be buffered up to OBUFLEN characters or up to a \n and sent out as a hex
* coded gdb packet.
*/
int gdbstub_obuf_flush(void)
{
int i;
gdbPacketStart();
gdbPacketChar('O');
for (i = 0; i < obufpos; i++) {
gdbPacketHex(obuf[i], 8);
}
gdbPacketEnd();
obufpos = 0;
return i;
}
/* function used by any printf function */
int ets_putc(int c)
{
/* before gdbstub is initialized we simply send the char */
if (!gdbstub_initialized) {
gdbSendChar(c);
return c;
}
/* put the character into the output buffer */
obuf[obufpos++] = c;
/* flush the buffer if newline is given or buffer is full */
if (c == '\n' || obufpos == OBUFLEN) {
gdbstub_obuf_flush();
}
return c;
}
/* function used with single characters, e.g. echoed input in shell */
int putchar(int c)
{
/* before gdbstub is initialized we simply send the char */
if (!gdbstub_initialized) {
gdbSendChar(c);
return c;
}
/* if there is something in obuf, flush it first */
if (obufpos) {
gdbstub_obuf_flush();
}
/* send the single character */
gdbPacketStart();
gdbPacketChar('O');
gdbPacketHex(c, 8);
gdbPacketEnd();
return c;
}
#endif
/*
* We use Xtensa standard exception handlers to deal with exceptions. We can
* use those functions to catch any fatal exceptions and invoke the debugger
* when this happens.
*/
static void ATTR_GDBINIT install_exceptions(void)
{
unsigned int i;
unsigned int exno[] = {
EXCCAUSE_ILLEGAL, EXCCAUSE_SYSCALL,
EXCCAUSE_INSTR_ERROR,
EXCCAUSE_DIVIDE_BY_ZERO, EXCCAUSE_UNALIGNED,
EXCCAUSE_INSTR_DATA_ERROR, EXCCAUSE_LOAD_STORE_DATA_ERROR,
EXCCAUSE_INSTR_ADDR_ERROR, EXCCAUSE_LOAD_STORE_ADDR_ERROR,
EXCCAUSE_INSTR_PROHIBITED, EXCCAUSE_LOAD_PROHIBITED,
EXCCAUSE_STORE_PROHIBITED
};
for (i = 0; i < (sizeof(exno)/sizeof(exno[0])); i++)
_xtos_set_exception_handler(exno[i], gdb_exception_handler);
}
#if GDBSTUB_CTRLC_BREAK
static void ATTR_GDBFN uart_hdlr(void *arg)
{
assert(thread_get_active() != NULL);
assert(thread_get_active()->sp != NULL);
XtExcFrame* frame = (XtExcFrame *)thread_get_active()->sp;
int doDebug=0;
int fifolen=0;
/* Save the extra registers the standard exception handlers don't save */
gdbstub_save_extra_sfrs_for_exception();
fifolen = (READ_PERI_REG(UART_STATUS(0)) >> UART_RXFIFO_CNT_S) & UART_RXFIFO_CNT;
while (fifolen != 0)
{
uint8_t data = READ_PERI_REG(UART_FIFO(0)) & 0xff;
if (data == 0x03) {
/* if char is control-C, break execution and do in debug mode */
doDebug=1;
}
else if (data != '+' && data != '-' && !_gdbstub_in_rcv_packet) {
/* if char is not '+' (gdb ack/nak), forward it to stdio */
extern isrpipe_t stdio_uart_isrpipe;
isrpipe_write_one(&stdio_uart_isrpipe, data);
}
fifolen--;
}
WRITE_PERI_REG(UART_INT_CLR(0), UART_RXFIFO_FULL_INT_CLR | UART_RXFIFO_TOUT_INT_CLR);
if (doDebug)
{
/* copy the registers the Xtensa exception handler did save to gdbstub_regs */
ets_memcpy(&gdbstub_regs.exc_frame, frame, sizeof(XtExcFrame));
/* mark as user break reason */
gdbstub_regs.exc_frame_gdb.reason = 0xff;
ets_wdt_disable();
sendReason();
while (gdbReadCommand() != ST_CONT) { }
ets_wdt_enable();
/* Copy changed registers back to the standard exception frame. */
ets_memcpy(frame, &gdbstub_regs.exc_frame, sizeof(XtExcFrame));
}
}
static void ATTR_GDBINIT install_uart_hdlr(void)
{
/* set UART interrupt handler to the handler of gdbstub */
ets_isr_attach(ETS_UART_INUM, (ets_isr_t)uart_hdlr, NULL);
/* clear all interrupts */
SET_PERI_REG_MASK(UART_INT_ENA(0), UART_RXFIFO_FULL_INT_ENA|UART_RXFIFO_TOUT_INT_ENA);
/* enable uart interrupt */
ets_isr_unmask((1 << ETS_UART_INUM));
}
#endif /* GDBSTUB_CTRLC_BREAK */
extern bool _esp_output_active;
/* gdbstub initialization routine. */
void ATTR_GDBINIT gdbstub_init(void)
{
#if GDBSTUB_CTRLC_BREAK
install_uart_hdlr();
#endif
install_exceptions();
gdbstub_init_debug_entry();
gdbstub_initialized = true;
#if GDBSTUB_BREAK_ON_INIT
/* before break, PS.INTLEVEL has to be set correctly to allow debug exceptions */
uint32_t _old_intlevel;
__asm__ volatile ("rsil %0, " XTSTR(XCHAL_DEBUGLEVEL - 1) : "=a" (_old_intlevel));
(void)_old_intlevel;
/* now lets break on init */
gdbstub_do_break();
#endif
}