From 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:29:51 +0200 Subject: Adding upstream version 2.06. Signed-off-by: Daniel Baumann --- grub-core/gdb/cstub.c | 366 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 366 insertions(+) create mode 100644 grub-core/gdb/cstub.c (limited to 'grub-core/gdb/cstub.c') diff --git a/grub-core/gdb/cstub.c b/grub-core/gdb/cstub.c new file mode 100644 index 0000000..b64acd7 --- /dev/null +++ b/grub-core/gdb/cstub.c @@ -0,0 +1,366 @@ +/* cstub.c - machine independent portion of remote GDB stub */ +/* + * Copyright (C) 2006 Lubomir Kundrak + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include + +static const char hexchars[] = "0123456789abcdef"; +int grub_gdb_regs[GRUB_MACHINE_NR_REGS]; + +#define GRUB_GDB_COMBUF_SIZE 400 /* At least sizeof(grub_gdb_regs)*2 are needed for + register packets. */ +static char grub_gdb_inbuf[GRUB_GDB_COMBUF_SIZE + 1]; +static char grub_gdb_outbuf[GRUB_GDB_COMBUF_SIZE + 1]; + +struct grub_serial_port *grub_gdb_port; + +static int +hex (char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return (ch - 'a' + 10); + if ((ch >= '0') && (ch <= '9')) + return (ch - '0'); + if ((ch >= 'A') && (ch <= 'F')) + return (ch - 'A' + 10); + return (-1); +} + +/* Scan for the sequence $#. */ +static char * +grub_gdb_getpacket (void) +{ + char *buffer = &grub_gdb_inbuf[0]; + unsigned char checksum; + unsigned char xmitcsum; + int count; + int ch; + + while (1) + { + /* Wait around for the start character, ignore all other + characters. */ + while ((ch = grub_serial_port_fetch (grub_gdb_port)) != '$'); + + retry: + checksum = 0; + xmitcsum = -1; + count = 0; + + /* Now read until a # or end of buffer is found. */ + while (count < GRUB_GDB_COMBUF_SIZE) + { + do + ch = grub_serial_port_fetch (grub_gdb_port); + while (ch < 0); + if (ch == '$') + goto retry; + if (ch == '#') + break; + checksum += ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + if (ch == '#') + { + do + ch = grub_serial_port_fetch (grub_gdb_port); + while (ch < 0); + xmitcsum = hex (ch) << 4; + do + ch = grub_serial_port_fetch (grub_gdb_port); + while (ch < 0); + xmitcsum += hex (ch); + + if (checksum != xmitcsum) + grub_serial_port_put (grub_gdb_port, '-'); /* Failed checksum. */ + else + { + grub_serial_port_put (grub_gdb_port, '+'); /* Successful transfer. */ + + /* If a sequence char is present, reply the sequence ID. */ + if (buffer[2] == ':') + { + grub_serial_port_put (grub_gdb_port, buffer[0]); + grub_serial_port_put (grub_gdb_port, buffer[1]); + + return &buffer[3]; + } + return &buffer[0]; + } + } + } +} + +/* Send the packet in buffer. */ +static void +grub_gdb_putpacket (char *buffer) +{ + grub_uint8_t checksum; + + /* $#. */ + do + { + char *ptr; + grub_serial_port_put (grub_gdb_port, '$'); + checksum = 0; + + for (ptr = buffer; *ptr; ptr++) + { + grub_serial_port_put (grub_gdb_port, *ptr); + checksum += *ptr; + } + + grub_serial_port_put (grub_gdb_port, '#'); + grub_serial_port_put (grub_gdb_port, hexchars[checksum >> 4]); + grub_serial_port_put (grub_gdb_port, hexchars[checksum & 0xf]); + } + while (grub_serial_port_fetch (grub_gdb_port) != '+'); +} + +/* Convert the memory pointed to by mem into hex, placing result in buf. + Return a pointer to the last char put in buf (NULL). */ +static char * +grub_gdb_mem2hex (char *mem, char *buf, grub_size_t count) +{ + grub_size_t i; + unsigned char ch; + + for (i = 0; i < count; i++) + { + ch = *mem++; + *buf++ = hexchars[ch >> 4]; + *buf++ = hexchars[ch % 16]; + } + *buf = 0; + return (buf); +} + +/* Convert the hex array pointed to by buf into binary to be placed in mem. + Return a pointer to the character after the last byte written. */ +static char * +grub_gdb_hex2mem (char *buf, char *mem, int count) +{ + int i; + unsigned char ch; + + for (i = 0; i < count; i++) + { + ch = hex (*buf++) << 4; + ch = ch + hex (*buf++); + *mem++ = ch; + } + return (mem); +} + +/* Convert hex characters to int and return the number of characters + processed. */ +static int +grub_gdb_hex2int (char **ptr, grub_uint64_t *int_value) +{ + int num_chars = 0; + int hex_value; + + *int_value = 0; + + while (**ptr) + { + hex_value = hex (**ptr); + if (hex_value >= 0) + { + *int_value = (*int_value << 4) | hex_value; + num_chars++; + } + else + break; + + (*ptr)++; + } + + return (num_chars); +} + +/* This function does all command procesing for interfacing to gdb. */ +void __attribute__ ((regparm(3))) +grub_gdb_trap (int trap_no) +{ + unsigned int sig_no; + int stepping; + grub_uint64_t addr; + grub_uint64_t length; + char *ptr; + + if (!grub_gdb_port) + { + grub_printf ("Unhandled exception 0x%x at ", trap_no); + grub_backtrace_print_address ((void *) grub_gdb_regs[PC]); + grub_printf ("\n"); + grub_backtrace_pointer ((void *) grub_gdb_regs[EBP]); + grub_fatal ("Unhandled exception"); + } + + sig_no = grub_gdb_trap2sig (trap_no); + + ptr = grub_gdb_outbuf; + + /* Reply to host that an exception has occurred. */ + + *ptr++ = 'T'; /* Notify gdb with signo, PC, FP and SP. */ + + *ptr++ = hexchars[sig_no >> 4]; + *ptr++ = hexchars[sig_no & 0xf]; + + /* Stack pointer. */ + *ptr++ = hexchars[SP]; + *ptr++ = ':'; + ptr = grub_gdb_mem2hex ((char *) &grub_gdb_regs[ESP], ptr, 4); + *ptr++ = ';'; + + /* Frame pointer. */ + *ptr++ = hexchars[FP]; + *ptr++ = ':'; + ptr = grub_gdb_mem2hex ((char *) &grub_gdb_regs[EBP], ptr, 4); + *ptr++ = ';'; + + /* Program counter. */ + *ptr++ = hexchars[PC]; + *ptr++ = ':'; + ptr = grub_gdb_mem2hex ((char *) &grub_gdb_regs[PC], ptr, 4); + *ptr++ = ';'; + + *ptr = '\0'; + + grub_gdb_putpacket (grub_gdb_outbuf); + + stepping = 0; + + while (1) + { + grub_gdb_outbuf[0] = 0; + ptr = grub_gdb_getpacket (); + + switch (*ptr++) + { + case '?': + grub_gdb_outbuf[0] = 'S'; + grub_gdb_outbuf[1] = hexchars[sig_no >> 4]; + grub_gdb_outbuf[2] = hexchars[sig_no & 0xf]; + grub_gdb_outbuf[3] = 0; + break; + + /* Return values of the CPU registers. */ + case 'g': + grub_gdb_mem2hex ((char *) grub_gdb_regs, grub_gdb_outbuf, + sizeof (grub_gdb_regs)); + break; + + /* Set values of the CPU registers -- return OK. */ + case 'G': + grub_gdb_hex2mem (ptr, (char *) grub_gdb_regs, + sizeof (grub_gdb_regs)); + grub_strcpy (grub_gdb_outbuf, "OK"); + break; + + /* Set the value of a single CPU register -- return OK. */ + case 'P': + { + grub_uint64_t regno; + + if (grub_gdb_hex2int (&ptr, ®no) && *ptr++ == '=') + if (regno < GRUB_MACHINE_NR_REGS) + { + grub_gdb_hex2mem (ptr, (char *) &grub_gdb_regs[regno], 4); + grub_strcpy (grub_gdb_outbuf, "OK"); + break; + } + /* FIXME: GDB requires setting orig_eax. I don't know what's + this register is about. For now just simulate setting any + registers. */ + grub_strcpy (grub_gdb_outbuf, /*"E01"*/ "OK"); + break; + } + + /* mAA..AA,LLLL: Read LLLL bytes at address AA..AA. */ + case 'm': + /* Try to read %x,%x. Set ptr = 0 if successful. */ + if (grub_gdb_hex2int (&ptr, &addr)) + if (*(ptr++) == ',') + if (grub_gdb_hex2int (&ptr, &length)) + { + ptr = 0; + grub_gdb_mem2hex ((char *) (grub_addr_t) addr, + grub_gdb_outbuf, length); + } + if (ptr) + grub_strcpy (grub_gdb_outbuf, "E01"); + break; + + /* MAA..AA,LLLL: Write LLLL bytes at address AA.AA -- return OK. */ + case 'M': + /* Try to read %x,%x. Set ptr = 0 if successful. */ + if (grub_gdb_hex2int (&ptr, &addr)) + if (*(ptr++) == ',') + if (grub_gdb_hex2int (&ptr, &length)) + if (*(ptr++) == ':') + { + grub_gdb_hex2mem (ptr, (char *) (grub_addr_t) addr, length); + grub_strcpy (grub_gdb_outbuf, "OK"); + ptr = 0; + } + if (ptr) + { + grub_strcpy (grub_gdb_outbuf, "E02"); + } + break; + + /* sAA..AA: Step one instruction from AA..AA(optional). */ + case 's': + stepping = 1; + /* FALLTHROUGH */ + + /* cAA..AA: Continue at address AA..AA(optional). */ + case 'c': + /* try to read optional parameter, pc unchanged if no parm */ + if (grub_gdb_hex2int (&ptr, &addr)) + grub_gdb_regs[PC] = addr; + + /* Clear the trace bit. */ + grub_gdb_regs[PS] &= 0xfffffeff; + + /* Set the trace bit if we're stepping. */ + if (stepping) + grub_gdb_regs[PS] |= 0x100; + + return; + + /* Kill the program. */ + case 'k': + /* Do nothing. */ + return; + } + + /* Reply to the request. */ + grub_gdb_putpacket (grub_gdb_outbuf); + } +} + -- cgit v1.2.3