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Diffstat (limited to 'contrib/gdb/gdb/go32-nat.c')
| -rw-r--r-- | contrib/gdb/gdb/go32-nat.c | 1963 |
1 files changed, 1963 insertions, 0 deletions
diff --git a/contrib/gdb/gdb/go32-nat.c b/contrib/gdb/gdb/go32-nat.c new file mode 100644 index 0000000..0932ddb --- /dev/null +++ b/contrib/gdb/gdb/go32-nat.c @@ -0,0 +1,1963 @@ +/* Native debugging support for Intel x86 running DJGPP. + Copyright 1997, 1999, 2000, 2001 Free Software Foundation, Inc. + Written by Robert Hoehne. + + This file is part of GDB. + + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <fcntl.h> + +#include "defs.h" +#include "inferior.h" +#include "gdb_wait.h" +#include "gdbcore.h" +#include "command.h" +#include "gdbcmd.h" +#include "floatformat.h" +#include "buildsym.h" +#include "i387-tdep.h" +#include "i386-tdep.h" +#include "value.h" +#include "regcache.h" +#include "gdb_string.h" + +#include <stdio.h> /* might be required for __DJGPP_MINOR__ */ +#include <stdlib.h> +#include <ctype.h> +#include <errno.h> +#include <unistd.h> +#include <sys/utsname.h> +#include <io.h> +#include <dos.h> +#include <dpmi.h> +#include <go32.h> +#include <sys/farptr.h> +#include <debug/v2load.h> +#include <debug/dbgcom.h> +#if __DJGPP_MINOR__ > 2 +#include <debug/redir.h> +#endif + +#if __DJGPP_MINOR__ < 3 +/* This code will be provided from DJGPP 2.03 on. Until then I code it + here */ +typedef struct + { + unsigned short sig0; + unsigned short sig1; + unsigned short sig2; + unsigned short sig3; + unsigned short exponent:15; + unsigned short sign:1; + } +NPXREG; + +typedef struct + { + unsigned int control; + unsigned int status; + unsigned int tag; + unsigned int eip; + unsigned int cs; + unsigned int dataptr; + unsigned int datasel; + NPXREG reg[8]; + } +NPX; + +static NPX npx; + +static void save_npx (void); /* Save the FPU of the debugged program */ +static void load_npx (void); /* Restore the FPU of the debugged program */ + +/* ------------------------------------------------------------------------- */ +/* Store the contents of the NPX in the global variable `npx'. */ +/* *INDENT-OFF* */ + +static void +save_npx (void) +{ + asm ("inb $0xa0, %%al \n\ + testb $0x20, %%al \n\ + jz 1f \n\ + xorb %%al, %%al \n\ + outb %%al, $0xf0 \n\ + movb $0x20, %%al \n\ + outb %%al, $0xa0 \n\ + outb %%al, $0x20 \n\ +1: \n\ + fnsave %0 \n\ + fwait " +: "=m" (npx) +: /* No input */ +: "%eax"); +} + +/* *INDENT-ON* */ + + +/* ------------------------------------------------------------------------- */ +/* Reload the contents of the NPX from the global variable `npx'. */ + +static void +load_npx (void) +{ + asm ("frstor %0":"=m" (npx)); +} +/* ------------------------------------------------------------------------- */ +/* Stubs for the missing redirection functions. */ +typedef struct { + char *command; + int redirected; +} cmdline_t; + +void +redir_cmdline_delete (cmdline_t *ptr) +{ + ptr->redirected = 0; +} + +int +redir_cmdline_parse (const char *args, cmdline_t *ptr) +{ + return -1; +} + +int +redir_to_child (cmdline_t *ptr) +{ + return 1; +} + +int +redir_to_debugger (cmdline_t *ptr) +{ + return 1; +} + +int +redir_debug_init (cmdline_t *ptr) +{ + return 0; +} +#endif /* __DJGPP_MINOR < 3 */ + +typedef enum { wp_insert, wp_remove, wp_count } wp_op; + +/* This holds the current reference counts for each debug register. */ +static int dr_ref_count[4]; + +#define SOME_PID 42 + +static int prog_has_started = 0; +static void go32_open (char *name, int from_tty); +static void go32_close (int quitting); +static void go32_attach (char *args, int from_tty); +static void go32_detach (char *args, int from_tty); +static void go32_resume (ptid_t ptid, int step, + enum target_signal siggnal); +static ptid_t go32_wait (ptid_t ptid, + struct target_waitstatus *status); +static void go32_fetch_registers (int regno); +static void store_register (int regno); +static void go32_store_registers (int regno); +static void go32_prepare_to_store (void); +static int go32_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, + int write, + struct mem_attrib *attrib, + struct target_ops *target); +static void go32_files_info (struct target_ops *target); +static void go32_stop (void); +static void go32_kill_inferior (void); +static void go32_create_inferior (char *exec_file, char *args, char **env); +static void go32_mourn_inferior (void); +static int go32_can_run (void); + +static struct target_ops go32_ops; +static void go32_terminal_init (void); +static void go32_terminal_inferior (void); +static void go32_terminal_ours (void); + +#define r_ofs(x) (offsetof(TSS,x)) + +static struct +{ + size_t tss_ofs; + size_t size; +} +regno_mapping[] = +{ + {r_ofs (tss_eax), 4}, /* normal registers, from a_tss */ + {r_ofs (tss_ecx), 4}, + {r_ofs (tss_edx), 4}, + {r_ofs (tss_ebx), 4}, + {r_ofs (tss_esp), 4}, + {r_ofs (tss_ebp), 4}, + {r_ofs (tss_esi), 4}, + {r_ofs (tss_edi), 4}, + {r_ofs (tss_eip), 4}, + {r_ofs (tss_eflags), 4}, + {r_ofs (tss_cs), 2}, + {r_ofs (tss_ss), 2}, + {r_ofs (tss_ds), 2}, + {r_ofs (tss_es), 2}, + {r_ofs (tss_fs), 2}, + {r_ofs (tss_gs), 2}, + {0, 10}, /* 8 FP registers, from npx.reg[] */ + {1, 10}, + {2, 10}, + {3, 10}, + {4, 10}, + {5, 10}, + {6, 10}, + {7, 10}, + /* The order of the next 7 registers must be consistent + with their numbering in config/i386/tm-i386.h, which see. */ + {0, 2}, /* control word, from npx */ + {4, 2}, /* status word, from npx */ + {8, 2}, /* tag word, from npx */ + {16, 2}, /* last FP exception CS from npx */ + {12, 4}, /* last FP exception EIP from npx */ + {24, 2}, /* last FP exception operand selector from npx */ + {20, 4}, /* last FP exception operand offset from npx */ + {18, 2} /* last FP opcode from npx */ +}; + +static struct + { + int go32_sig; + enum target_signal gdb_sig; + } +sig_map[] = +{ + {0, TARGET_SIGNAL_FPE}, + {1, TARGET_SIGNAL_TRAP}, + /* Exception 2 is triggered by the NMI. DJGPP handles it as SIGILL, + but I think SIGBUS is better, since the NMI is usually activated + as a result of a memory parity check failure. */ + {2, TARGET_SIGNAL_BUS}, + {3, TARGET_SIGNAL_TRAP}, + {4, TARGET_SIGNAL_FPE}, + {5, TARGET_SIGNAL_SEGV}, + {6, TARGET_SIGNAL_ILL}, + {7, TARGET_SIGNAL_EMT}, /* no-coprocessor exception */ + {8, TARGET_SIGNAL_SEGV}, + {9, TARGET_SIGNAL_SEGV}, + {10, TARGET_SIGNAL_BUS}, + {11, TARGET_SIGNAL_SEGV}, + {12, TARGET_SIGNAL_SEGV}, + {13, TARGET_SIGNAL_SEGV}, + {14, TARGET_SIGNAL_SEGV}, + {16, TARGET_SIGNAL_FPE}, + {17, TARGET_SIGNAL_BUS}, + {31, TARGET_SIGNAL_ILL}, + {0x1b, TARGET_SIGNAL_INT}, + {0x75, TARGET_SIGNAL_FPE}, + {0x78, TARGET_SIGNAL_ALRM}, + {0x79, TARGET_SIGNAL_INT}, + {0x7a, TARGET_SIGNAL_QUIT}, + {-1, TARGET_SIGNAL_LAST} +}; + +static struct { + enum target_signal gdb_sig; + int djgpp_excepno; +} excepn_map[] = { + {TARGET_SIGNAL_0, -1}, + {TARGET_SIGNAL_ILL, 6}, /* Invalid Opcode */ + {TARGET_SIGNAL_EMT, 7}, /* triggers SIGNOFP */ + {TARGET_SIGNAL_SEGV, 13}, /* GPF */ + {TARGET_SIGNAL_BUS, 17}, /* Alignment Check */ + /* The rest are fake exceptions, see dpmiexcp.c in djlsr*.zip for + details. */ + {TARGET_SIGNAL_TERM, 0x1b}, /* triggers Ctrl-Break type of SIGINT */ + {TARGET_SIGNAL_FPE, 0x75}, + {TARGET_SIGNAL_INT, 0x79}, + {TARGET_SIGNAL_QUIT, 0x7a}, + {TARGET_SIGNAL_ALRM, 0x78}, /* triggers SIGTIMR */ + {TARGET_SIGNAL_PROF, 0x78}, + {TARGET_SIGNAL_LAST, -1} +}; + +static void +go32_open (char *name, int from_tty) +{ + printf_unfiltered ("Done. Use the \"run\" command to run the program.\n"); +} + +static void +go32_close (int quitting) +{ +} + +static void +go32_attach (char *args, int from_tty) +{ + error ("\ +You cannot attach to a running program on this platform.\n\ +Use the `run' command to run DJGPP programs."); +} + +static void +go32_detach (char *args, int from_tty) +{ +} + +static int resume_is_step; +static int resume_signal = -1; + +static void +go32_resume (ptid_t ptid, int step, enum target_signal siggnal) +{ + int i; + + resume_is_step = step; + + if (siggnal != TARGET_SIGNAL_0 && siggnal != TARGET_SIGNAL_TRAP) + { + for (i = 0, resume_signal = -1; + excepn_map[i].gdb_sig != TARGET_SIGNAL_LAST; i++) + if (excepn_map[i].gdb_sig == siggnal) + { + resume_signal = excepn_map[i].djgpp_excepno; + break; + } + if (resume_signal == -1) + printf_unfiltered ("Cannot deliver signal %s on this platform.\n", + target_signal_to_name (siggnal)); + } +} + +static char child_cwd[FILENAME_MAX]; + +static ptid_t +go32_wait (ptid_t ptid, struct target_waitstatus *status) +{ + int i; + unsigned char saved_opcode; + unsigned long INT3_addr = 0; + int stepping_over_INT = 0; + + a_tss.tss_eflags &= 0xfeff; /* reset the single-step flag (TF) */ + if (resume_is_step) + { + /* If the next instruction is INT xx or INTO, we need to handle + them specially. Intel manuals say that these instructions + reset the single-step flag (a.k.a. TF). However, it seems + that, at least in the DPMI environment, and at least when + stepping over the DPMI interrupt 31h, the problem is having + TF set at all when INT 31h is executed: the debuggee either + crashes (and takes the system with it) or is killed by a + SIGTRAP. + + So we need to emulate single-step mode: we put an INT3 opcode + right after the INT xx instruction, let the debuggee run + until it hits INT3 and stops, then restore the original + instruction which we overwrote with the INT3 opcode, and back + up the debuggee's EIP to that instruction. */ + read_child (a_tss.tss_eip, &saved_opcode, 1); + if (saved_opcode == 0xCD || saved_opcode == 0xCE) + { + unsigned char INT3_opcode = 0xCC; + + INT3_addr + = saved_opcode == 0xCD ? a_tss.tss_eip + 2 : a_tss.tss_eip + 1; + stepping_over_INT = 1; + read_child (INT3_addr, &saved_opcode, 1); + write_child (INT3_addr, &INT3_opcode, 1); + } + else + a_tss.tss_eflags |= 0x0100; /* normal instruction: set TF */ + } + + /* The special value FFFFh in tss_trap indicates to run_child that + tss_irqn holds a signal to be delivered to the debuggee. */ + if (resume_signal <= -1) + { + a_tss.tss_trap = 0; + a_tss.tss_irqn = 0xff; + } + else + { + a_tss.tss_trap = 0xffff; /* run_child looks for this */ + a_tss.tss_irqn = resume_signal; + } + + /* The child might change working directory behind our back. The + GDB users won't like the side effects of that when they work with + relative file names, and GDB might be confused by its current + directory not being in sync with the truth. So we always make a + point of changing back to where GDB thinks is its cwd, when we + return control to the debugger, but restore child's cwd before we + run it. */ + /* Initialize child_cwd, before the first call to run_child and not + in the initialization, so the child get also the changed directory + set with the gdb-command "cd ..." */ + if (!*child_cwd) + /* Initialize child's cwd with the current one. */ + getcwd (child_cwd, sizeof (child_cwd)); + + chdir (child_cwd); + +#if __DJGPP_MINOR__ < 3 + load_npx (); +#endif + run_child (); +#if __DJGPP_MINOR__ < 3 + save_npx (); +#endif + + /* Did we step over an INT xx instruction? */ + if (stepping_over_INT && a_tss.tss_eip == INT3_addr + 1) + { + /* Restore the original opcode. */ + a_tss.tss_eip--; /* EIP points *after* the INT3 instruction */ + write_child (a_tss.tss_eip, &saved_opcode, 1); + /* Simulate a TRAP exception. */ + a_tss.tss_irqn = 1; + a_tss.tss_eflags |= 0x0100; + } + + getcwd (child_cwd, sizeof (child_cwd)); /* in case it has changed */ + chdir (current_directory); + + if (a_tss.tss_irqn == 0x21) + { + status->kind = TARGET_WAITKIND_EXITED; + status->value.integer = a_tss.tss_eax & 0xff; + } + else + { + status->value.sig = TARGET_SIGNAL_UNKNOWN; + status->kind = TARGET_WAITKIND_STOPPED; + for (i = 0; sig_map[i].go32_sig != -1; i++) + { + if (a_tss.tss_irqn == sig_map[i].go32_sig) + { +#if __DJGPP_MINOR__ < 3 + if ((status->value.sig = sig_map[i].gdb_sig) != + TARGET_SIGNAL_TRAP) + status->kind = TARGET_WAITKIND_SIGNALLED; +#else + status->value.sig = sig_map[i].gdb_sig; +#endif + break; + } + } + } + return pid_to_ptid (SOME_PID); +} + +static void +fetch_register (int regno) +{ + if (regno < FP0_REGNUM) + supply_register (regno, (char *) &a_tss + regno_mapping[regno].tss_ofs); + else if (i386_fp_regnum_p (regno) || i386_fpc_regnum_p (regno)) + i387_supply_fsave (current_regcache, regno, &npx); + else + internal_error (__FILE__, __LINE__, + "Invalid register no. %d in fetch_register.", regno); +} + +static void +go32_fetch_registers (int regno) +{ + if (regno >= 0) + fetch_register (regno); + else + { + for (regno = 0; regno < FP0_REGNUM; regno++) + fetch_register (regno); + i387_supply_fsave (current_regcache, -1, &npx); + } +} + +static void +store_register (int regno) +{ + if (regno < FP0_REGNUM) + regcache_collect (regno, (char *) &a_tss + regno_mapping[regno].tss_ofs); + else if (i386_fp_regnum_p (regno) || i386_fpc_regnum_p (regno)) + i387_fill_fsave ((char *) &npx, regno); + else + internal_error (__FILE__, __LINE__, + "Invalid register no. %d in store_register.", regno); +} + +static void +go32_store_registers (int regno) +{ + unsigned r; + + if (regno >= 0) + store_register (regno); + else + { + for (r = 0; r < FP0_REGNUM; r++) + store_register (r); + i387_fill_fsave ((char *) &npx, -1); + } +} + +static void +go32_prepare_to_store (void) +{ +} + +static int +go32_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write, + struct mem_attrib *attrib, struct target_ops *target) +{ + if (write) + { + if (write_child (memaddr, myaddr, len)) + { + return 0; + } + else + { + return len; + } + } + else + { + if (read_child (memaddr, myaddr, len)) + { + return 0; + } + else + { + return len; + } + } +} + +static cmdline_t child_cmd; /* parsed child's command line kept here */ + +static void +go32_files_info (struct target_ops *target) +{ + printf_unfiltered ("You are running a DJGPP V2 program.\n"); +} + +static void +go32_stop (void) +{ + normal_stop (); + cleanup_client (); + inferior_ptid = null_ptid; + prog_has_started = 0; +} + +static void +go32_kill_inferior (void) +{ + redir_cmdline_delete (&child_cmd); + resume_signal = -1; + resume_is_step = 0; + unpush_target (&go32_ops); +} + +static void +go32_create_inferior (char *exec_file, char *args, char **env) +{ + extern char **environ; + jmp_buf start_state; + char *cmdline; + char **env_save = environ; + size_t cmdlen; + + /* If no exec file handed to us, get it from the exec-file command -- with + a good, common error message if none is specified. */ + if (exec_file == 0) + exec_file = get_exec_file (1); + + if (prog_has_started) + { + go32_stop (); + go32_kill_inferior (); + } + resume_signal = -1; + resume_is_step = 0; + + /* Initialize child's cwd as empty to be initialized when starting + the child. */ + *child_cwd = 0; + + /* Init command line storage. */ + if (redir_debug_init (&child_cmd) == -1) + internal_error (__FILE__, __LINE__, + "Cannot allocate redirection storage: not enough memory.\n"); + + /* Parse the command line and create redirections. */ + if (strpbrk (args, "<>")) + { + if (redir_cmdline_parse (args, &child_cmd) == 0) + args = child_cmd.command; + else + error ("Syntax error in command line."); + } + else + child_cmd.command = xstrdup (args); + + cmdlen = strlen (args); + /* v2loadimage passes command lines via DOS memory, so it cannot + possibly handle commands longer than 1MB. */ + if (cmdlen > 1024*1024) + error ("Command line too long."); + + cmdline = xmalloc (cmdlen + 4); + strcpy (cmdline + 1, args); + /* If the command-line length fits into DOS 126-char limits, use the + DOS command tail format; otherwise, tell v2loadimage to pass it + through a buffer in conventional memory. */ + if (cmdlen < 127) + { + cmdline[0] = strlen (args); + cmdline[cmdlen + 1] = 13; + } + else + cmdline[0] = 0xff; /* signal v2loadimage it's a long command */ + + environ = env; + + if (v2loadimage (exec_file, cmdline, start_state)) + { + environ = env_save; + printf_unfiltered ("Load failed for image %s\n", exec_file); + exit (1); + } + environ = env_save; + xfree (cmdline); + + edi_init (start_state); +#if __DJGPP_MINOR__ < 3 + save_npx (); +#endif + + inferior_ptid = pid_to_ptid (SOME_PID); + push_target (&go32_ops); + clear_proceed_status (); + insert_breakpoints (); + proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0); + prog_has_started = 1; +} + +static void +go32_mourn_inferior (void) +{ + /* We need to make sure all the breakpoint enable bits in the DR7 + register are reset when the inferior exits. Otherwise, if they + rerun the inferior, the uncleared bits may cause random SIGTRAPs, + failure to set more watchpoints, and other calamities. It would + be nice if GDB itself would take care to remove all breakpoints + at all times, but it doesn't, probably under an assumption that + the OS cleans up when the debuggee exits. */ + i386_cleanup_dregs (); + go32_kill_inferior (); + generic_mourn_inferior (); +} + +static int +go32_can_run (void) +{ + return 1; +} + +/* Hardware watchpoint support. */ + +#define D_REGS edi.dr +#define CONTROL D_REGS[7] +#define STATUS D_REGS[6] + +/* Pass the address ADDR to the inferior in the I'th debug register. + Here we just store the address in D_REGS, the watchpoint will be + actually set up when go32_wait runs the debuggee. */ +void +go32_set_dr (int i, CORE_ADDR addr) +{ + if (i < 0 || i > 3) + internal_error (__FILE__, __LINE__, + "Invalid register %d in go32_set_dr.\n", i); + D_REGS[i] = addr; +} + +/* Pass the value VAL to the inferior in the DR7 debug control + register. Here we just store the address in D_REGS, the watchpoint + will be actually set up when go32_wait runs the debuggee. */ +void +go32_set_dr7 (unsigned val) +{ + CONTROL = val; +} + +/* Get the value of the DR6 debug status register from the inferior. + Here we just return the value stored in D_REGS, as we've got it + from the last go32_wait call. */ +unsigned +go32_get_dr6 (void) +{ + return STATUS; +} + +/* Put the device open on handle FD into either raw or cooked + mode, return 1 if it was in raw mode, zero otherwise. */ + +static int +device_mode (int fd, int raw_p) +{ + int oldmode, newmode; + __dpmi_regs regs; + + regs.x.ax = 0x4400; + regs.x.bx = fd; + __dpmi_int (0x21, ®s); + if (regs.x.flags & 1) + return -1; + newmode = oldmode = regs.x.dx; + + if (raw_p) + newmode |= 0x20; + else + newmode &= ~0x20; + + if (oldmode & 0x80) /* Only for character dev */ + { + regs.x.ax = 0x4401; + regs.x.bx = fd; + regs.x.dx = newmode & 0xff; /* Force upper byte zero, else it fails */ + __dpmi_int (0x21, ®s); + if (regs.x.flags & 1) + return -1; + } + return (oldmode & 0x20) == 0x20; +} + + +static int inf_mode_valid = 0; +static int inf_terminal_mode; + +/* This semaphore is needed because, amazingly enough, GDB calls + target.to_terminal_ours more than once after the inferior stops. + But we need the information from the first call only, since the + second call will always see GDB's own cooked terminal. */ +static int terminal_is_ours = 1; + +static void +go32_terminal_init (void) +{ + inf_mode_valid = 0; /* reinitialize, in case they are restarting child */ + terminal_is_ours = 1; +} + +static void +go32_terminal_info (char *args, int from_tty) +{ + printf_unfiltered ("Inferior's terminal is in %s mode.\n", + !inf_mode_valid + ? "default" : inf_terminal_mode ? "raw" : "cooked"); + +#if __DJGPP_MINOR__ > 2 + if (child_cmd.redirection) + { + int i; + + for (i = 0; i < DBG_HANDLES; i++) + { + if (child_cmd.redirection[i]->file_name) + printf_unfiltered ("\tFile handle %d is redirected to `%s'.\n", + i, child_cmd.redirection[i]->file_name); + else if (_get_dev_info (child_cmd.redirection[i]->inf_handle) == -1) + printf_unfiltered + ("\tFile handle %d appears to be closed by inferior.\n", i); + /* Mask off the raw/cooked bit when comparing device info words. */ + else if ((_get_dev_info (child_cmd.redirection[i]->inf_handle) & 0xdf) + != (_get_dev_info (i) & 0xdf)) + printf_unfiltered + ("\tFile handle %d appears to be redirected by inferior.\n", i); + } + } +#endif +} + +static void +go32_terminal_inferior (void) +{ + /* Redirect standard handles as child wants them. */ + errno = 0; + if (redir_to_child (&child_cmd) == -1) + { + redir_to_debugger (&child_cmd); + error ("Cannot redirect standard handles for program: %s.", + safe_strerror (errno)); + } + /* set the console device of the inferior to whatever mode + (raw or cooked) we found it last time */ + if (terminal_is_ours) + { + if (inf_mode_valid) + device_mode (0, inf_terminal_mode); + terminal_is_ours = 0; + } +} + +static void +go32_terminal_ours (void) +{ + /* Switch to cooked mode on the gdb terminal and save the inferior + terminal mode to be restored when it is resumed */ + if (!terminal_is_ours) + { + inf_terminal_mode = device_mode (0, 0); + if (inf_terminal_mode != -1) + inf_mode_valid = 1; + else + /* If device_mode returned -1, we don't know what happens with + handle 0 anymore, so make the info invalid. */ + inf_mode_valid = 0; + terminal_is_ours = 1; + + /* Restore debugger's standard handles. */ + errno = 0; + if (redir_to_debugger (&child_cmd) == -1) + { + redir_to_child (&child_cmd); + error ("Cannot redirect standard handles for debugger: %s.", + safe_strerror (errno)); + } + } +} + +static void +init_go32_ops (void) +{ + go32_ops.to_shortname = "djgpp"; + go32_ops.to_longname = "djgpp target process"; + go32_ops.to_doc = + "Program loaded by djgpp, when gdb is used as an external debugger"; + go32_ops.to_open = go32_open; + go32_ops.to_close = go32_close; + go32_ops.to_attach = go32_attach; + go32_ops.to_detach = go32_detach; + go32_ops.to_resume = go32_resume; + go32_ops.to_wait = go32_wait; + go32_ops.to_fetch_registers = go32_fetch_registers; + go32_ops.to_store_registers = go32_store_registers; + go32_ops.to_prepare_to_store = go32_prepare_to_store; + go32_ops.to_xfer_memory = go32_xfer_memory; + go32_ops.to_files_info = go32_files_info; + go32_ops.to_insert_breakpoint = memory_insert_breakpoint; + go32_ops.to_remove_breakpoint = memory_remove_breakpoint; + go32_ops.to_terminal_init = go32_terminal_init; + go32_ops.to_terminal_inferior = go32_terminal_inferior; + go32_ops.to_terminal_ours_for_output = go32_terminal_ours; + go32_ops.to_terminal_ours = go32_terminal_ours; + go32_ops.to_terminal_info = go32_terminal_info; + go32_ops.to_kill = go32_kill_inferior; + go32_ops.to_create_inferior = go32_create_inferior; + go32_ops.to_mourn_inferior = go32_mourn_inferior; + go32_ops.to_can_run = go32_can_run; + go32_ops.to_stop = go32_stop; + go32_ops.to_stratum = process_stratum; + go32_ops.to_has_all_memory = 1; + go32_ops.to_has_memory = 1; + go32_ops.to_has_stack = 1; + go32_ops.to_has_registers = 1; + go32_ops.to_has_execution = 1; + go32_ops.to_magic = OPS_MAGIC; + + /* Initialize child's cwd as empty to be initialized when starting + the child. */ + *child_cwd = 0; + + /* Initialize child's command line storage. */ + if (redir_debug_init (&child_cmd) == -1) + internal_error (__FILE__, __LINE__, + "Cannot allocate redirection storage: not enough memory.\n"); + + /* We are always processing GCC-compiled programs. */ + processing_gcc_compilation = 2; +} + +unsigned short windows_major, windows_minor; + +/* Compute the version Windows reports via Int 2Fh/AX=1600h. */ +static void +go32_get_windows_version(void) +{ + __dpmi_regs r; + + r.x.ax = 0x1600; + __dpmi_int(0x2f, &r); + if (r.h.al > 2 && r.h.al != 0x80 && r.h.al != 0xff + && (r.h.al > 3 || r.h.ah > 0)) + { + windows_major = r.h.al; + windows_minor = r.h.ah; + } + else + windows_major = 0xff; /* meaning no Windows */ +} + +/* A subroutine of go32_sysinfo to display memory info. */ +static void +print_mem (unsigned long datum, const char *header, int in_pages_p) +{ + if (datum != 0xffffffffUL) + { + if (in_pages_p) + datum <<= 12; + puts_filtered (header); + if (datum > 1024) + { + printf_filtered ("%lu KB", datum >> 10); + if (datum > 1024 * 1024) + printf_filtered (" (%lu MB)", datum >> 20); + } + else + printf_filtered ("%lu Bytes", datum); + puts_filtered ("\n"); + } +} + +/* Display assorted information about the underlying OS. */ +static void +go32_sysinfo (char *arg, int from_tty) +{ + struct utsname u; + char cpuid_vendor[13]; + unsigned cpuid_max = 0, cpuid_eax, cpuid_ebx, cpuid_ecx, cpuid_edx; + unsigned true_dos_version = _get_dos_version (1); + unsigned advertized_dos_version = ((unsigned int)_osmajor << 8) | _osminor; + int dpmi_flags; + char dpmi_vendor_info[129]; + int dpmi_vendor_available = + __dpmi_get_capabilities (&dpmi_flags, dpmi_vendor_info); + __dpmi_version_ret dpmi_version_data; + long eflags; + __dpmi_free_mem_info mem_info; + __dpmi_regs regs; + + cpuid_vendor[0] = '\0'; + if (uname (&u)) + strcpy (u.machine, "Unknown x86"); + else if (u.machine[0] == 'i' && u.machine[1] > 4) + { + /* CPUID with EAX = 0 returns the Vendor ID. */ + __asm__ __volatile__ ("xorl %%ebx, %%ebx;" + "xorl %%ecx, %%ecx;" + "xorl %%edx, %%edx;" + "movl $0, %%eax;" + "cpuid;" + "movl %%ebx, %0;" + "movl %%edx, %1;" + "movl %%ecx, %2;" + "movl %%eax, %3;" + : "=m" (cpuid_vendor[0]), + "=m" (cpuid_vendor[4]), + "=m" (cpuid_vendor[8]), + "=m" (cpuid_max) + : + : "%eax", "%ebx", "%ecx", "%edx"); + cpuid_vendor[12] = '\0'; + } + + printf_filtered ("CPU Type.......................%s", u.machine); + if (cpuid_vendor[0]) + printf_filtered (" (%s)", cpuid_vendor); + puts_filtered ("\n"); + + /* CPUID with EAX = 1 returns processor signature and features. */ + if (cpuid_max >= 1) + { + static char *brand_name[] = { + "", + " Celeron", + " III", + " III Xeon", + "", "", "", "", + " 4" + }; + char cpu_string[80]; + char cpu_brand[20]; + unsigned brand_idx; + int intel_p = strcmp (cpuid_vendor, "GenuineIntel") == 0; + int amd_p = strcmp (cpuid_vendor, "AuthenticAMD") == 0; + unsigned cpu_family, cpu_model; + + __asm__ __volatile__ ("movl $1, %%eax;" + "cpuid;" + : "=a" (cpuid_eax), + "=b" (cpuid_ebx), + "=d" (cpuid_edx) + : + : "%ecx"); + brand_idx = cpuid_ebx & 0xff; + cpu_family = (cpuid_eax >> 8) & 0xf; + cpu_model = (cpuid_eax >> 4) & 0xf; + cpu_brand[0] = '\0'; + if (intel_p) + { + if (brand_idx > 0 + && brand_idx < sizeof(brand_name)/sizeof(brand_name[0]) + && *brand_name[brand_idx]) + strcpy (cpu_brand, brand_name[brand_idx]); + else if (cpu_family == 5) + { + if (((cpuid_eax >> 12) & 3) == 0 && cpu_model == 4) + strcpy (cpu_brand, " MMX"); + else if (cpu_model > 1 && ((cpuid_eax >> 12) & 3) == 1) + strcpy (cpu_brand, " OverDrive"); + else if (cpu_model > 1 && ((cpuid_eax >> 12) & 3) == 2) + strcpy (cpu_brand, " Dual"); + } + else if (cpu_family == 6 && cpu_model < 8) + { + switch (cpu_model) + { + case 1: + strcpy (cpu_brand, " Pro"); + break; + case 3: + strcpy (cpu_brand, " II"); + break; + case 5: + strcpy (cpu_brand, " II Xeon"); + break; + case 6: + strcpy (cpu_brand, " Celeron"); + break; + case 7: + strcpy (cpu_brand, " III"); + break; + } + } + } + else if (amd_p) + { + switch (cpu_family) + { + case 4: + strcpy (cpu_brand, "486/5x86"); + break; + case 5: + switch (cpu_model) + { + case 0: + case 1: + case 2: + case 3: + strcpy (cpu_brand, "-K5"); + break; + case 6: + case 7: + strcpy (cpu_brand, "-K6"); + break; + case 8: + strcpy (cpu_brand, "-K6-2"); + break; + case 9: + strcpy (cpu_brand, "-K6-III"); + break; + } + break; + case 6: + switch (cpu_model) + { + case 1: + case 2: + case 4: + strcpy (cpu_brand, " Athlon"); + break; + case 3: + strcpy (cpu_brand, " Duron"); + break; + } + break; + } + } + sprintf (cpu_string, "%s%s Model %d Stepping %d", + intel_p ? "Pentium" : (amd_p ? "AMD" : "ix86"), + cpu_brand, cpu_model, cpuid_eax & 0xf); + printfi_filtered (31, "%s\n", cpu_string); + if (((cpuid_edx & (6 | (0x0d << 23))) != 0) + || ((cpuid_edx & 1) == 0) + || (amd_p && (cpuid_edx & (3 << 30)) != 0)) + { + puts_filtered ("CPU Features..................."); + /* We only list features which might be useful in the DPMI + environment. */ + if ((cpuid_edx & 1) == 0) + puts_filtered ("No FPU "); /* it's unusual to not have an FPU */ + if ((cpuid_edx & (1 << 1)) != 0) + puts_filtered ("VME "); + if ((cpuid_edx & (1 << 2)) != 0) + puts_filtered ("DE "); + if ((cpuid_edx & (1 << 4)) != 0) + puts_filtered ("TSC "); + if ((cpuid_edx & (1 << 23)) != 0) + puts_filtered ("MMX "); + if ((cpuid_edx & (1 << 25)) != 0) + puts_filtered ("SSE "); + if ((cpuid_edx & (1 << 26)) != 0) + puts_filtered ("SSE2 "); + if (amd_p) + { + if ((cpuid_edx & (1 << 31)) != 0) + puts_filtered ("3DNow! "); + if ((cpuid_edx & (1 << 30)) != 0) + puts_filtered ("3DNow!Ext"); + } + puts_filtered ("\n"); + } + } + puts_filtered ("\n"); + printf_filtered ("DOS Version....................%s %s.%s", + _os_flavor, u.release, u.version); + if (true_dos_version != advertized_dos_version) + printf_filtered (" (disguised as v%d.%d)", _osmajor, _osminor); + puts_filtered ("\n"); + if (!windows_major) + go32_get_windows_version (); + if (windows_major != 0xff) + { + const char *windows_flavor; + + printf_filtered ("Windows Version................%d.%02d (Windows ", + windows_major, windows_minor); + switch (windows_major) + { + case 3: + windows_flavor = "3.X"; + break; + case 4: + switch (windows_minor) + { + case 0: + windows_flavor = "95, 95A, or 95B"; + break; + case 3: + windows_flavor = "95B OSR2.1 or 95C OSR2.5"; + break; + case 10: + windows_flavor = "98 or 98 SE"; + break; + case 90: + windows_flavor = "ME"; + break; + default: + windows_flavor = "9X"; + break; + } + break; + default: + windows_flavor = "??"; + break; + } + printf_filtered ("%s)\n", windows_flavor); + } + else if (true_dos_version == 0x532 && advertized_dos_version == 0x500) + printf_filtered ("Windows Version................Windows NT or Windows 2000\n"); + puts_filtered ("\n"); + if (dpmi_vendor_available == 0) + { + /* The DPMI spec says the vendor string should be ASCIIZ, but + I don't trust the vendors to follow that... */ + if (!memchr (&dpmi_vendor_info[2], 0, 126)) + dpmi_vendor_info[128] = '\0'; + printf_filtered ("DPMI Host......................%s v%d.%d (capabilities: %#x)\n", + &dpmi_vendor_info[2], + (unsigned)dpmi_vendor_info[0], + (unsigned)dpmi_vendor_info[1], + ((unsigned)dpmi_flags & 0x7f)); + } + __dpmi_get_version (&dpmi_version_data); + printf_filtered ("DPMI Version...................%d.%02d\n", + dpmi_version_data.major, dpmi_version_data.minor); + printf_filtered ("DPMI Info......................%s-bit DPMI, with%s Virtual Memory support\n", + (dpmi_version_data.flags & 1) ? "32" : "16", + (dpmi_version_data.flags & 4) ? "" : "out"); + printfi_filtered (31, "Interrupts reflected to %s mode\n", + (dpmi_version_data.flags & 2) ? "V86" : "Real"); + printfi_filtered (31, "Processor type: i%d86\n", + dpmi_version_data.cpu); + printfi_filtered (31, "PIC base interrupt: Master: %#x Slave: %#x\n", + dpmi_version_data.master_pic, dpmi_version_data.slave_pic); + + /* a_tss is only initialized when the debuggee is first run. */ + if (prog_has_started) + { + __asm__ __volatile__ ("pushfl ; popl %0" : "=g" (eflags)); + printf_filtered ("Protection.....................Ring %d (in %s), with%s I/O protection\n", + a_tss.tss_cs & 3, (a_tss.tss_cs & 4) ? "LDT" : "GDT", + (a_tss.tss_cs & 3) > ((eflags >> 12) & 3) ? "" : "out"); + } + puts_filtered ("\n"); + __dpmi_get_free_memory_information (&mem_info); + print_mem (mem_info.total_number_of_physical_pages, + "DPMI Total Physical Memory.....", 1); + print_mem (mem_info.total_number_of_free_pages, + "DPMI Free Physical Memory......", 1); + print_mem (mem_info.size_of_paging_file_partition_in_pages, + "DPMI Swap Space................", 1); + print_mem (mem_info.linear_address_space_size_in_pages, + "DPMI Total Linear Address Size.", 1); + print_mem (mem_info.free_linear_address_space_in_pages, + "DPMI Free Linear Address Size..", 1); + print_mem (mem_info.largest_available_free_block_in_bytes, + "DPMI Largest Free Memory Block.", 0); + + regs.h.ah = 0x48; + regs.x.bx = 0xffff; + __dpmi_int (0x21, ®s); + print_mem (regs.x.bx << 4, "Free DOS Memory................", 0); + regs.x.ax = 0x5800; + __dpmi_int (0x21, ®s); + if ((regs.x.flags & 1) == 0) + { + static const char *dos_hilo[] = { + "Low", "", "", "", "High", "", "", "", "High, then Low" + }; + static const char *dos_fit[] = { + "First", "Best", "Last" + }; + int hilo_idx = (regs.x.ax >> 4) & 0x0f; + int fit_idx = regs.x.ax & 0x0f; + + if (hilo_idx > 8) + hilo_idx = 0; + if (fit_idx > 2) + fit_idx = 0; + printf_filtered ("DOS Memory Allocation..........%s memory, %s fit\n", + dos_hilo[hilo_idx], dos_fit[fit_idx]); + regs.x.ax = 0x5802; + __dpmi_int (0x21, ®s); + if ((regs.x.flags & 1) != 0) + regs.h.al = 0; + printfi_filtered (31, "UMBs %sin DOS memory chain\n", + regs.h.al == 0 ? "not " : ""); + } +} + +struct seg_descr { + unsigned short limit0 __attribute__((packed)); + unsigned short base0 __attribute__((packed)); + unsigned char base1 __attribute__((packed)); + unsigned stype:5 __attribute__((packed)); + unsigned dpl:2 __attribute__((packed)); + unsigned present:1 __attribute__((packed)); + unsigned limit1:4 __attribute__((packed)); + unsigned available:1 __attribute__((packed)); + unsigned dummy:1 __attribute__((packed)); + unsigned bit32:1 __attribute__((packed)); + unsigned page_granular:1 __attribute__((packed)); + unsigned char base2 __attribute__((packed)); +}; + +struct gate_descr { + unsigned short offset0 __attribute__((packed)); + unsigned short selector __attribute__((packed)); + unsigned param_count:5 __attribute__((packed)); + unsigned dummy:3 __attribute__((packed)); + unsigned stype:5 __attribute__((packed)); + unsigned dpl:2 __attribute__((packed)); + unsigned present:1 __attribute__((packed)); + unsigned short offset1 __attribute__((packed)); +}; + +/* Read LEN bytes starting at logical address ADDR, and put the result + into DEST. Return 1 if success, zero if not. */ +static int +read_memory_region (unsigned long addr, void *dest, size_t len) +{ + unsigned long dos_ds_limit = __dpmi_get_segment_limit (_dos_ds); + int retval = 1; + + /* For the low memory, we can simply use _dos_ds. */ + if (addr <= dos_ds_limit - len) + dosmemget (addr, len, dest); + else + { + /* For memory above 1MB we need to set up a special segment to + be able to access that memory. */ + int sel = __dpmi_allocate_ldt_descriptors (1); + + if (sel <= 0) + retval = 0; + else + { + int access_rights = __dpmi_get_descriptor_access_rights (sel); + size_t segment_limit = len - 1; + + /* Make sure the crucial bits in the descriptor access + rights are set correctly. Some DPMI providers might barf + if we set the segment limit to something that is not an + integral multiple of 4KB pages if the granularity bit is + not set to byte-granular, even though the DPMI spec says + it's the host's responsibility to set that bit correctly. */ + if (len > 1024 * 1024) + { + access_rights |= 0x8000; + /* Page-granular segments should have the low 12 bits of + the limit set. */ + segment_limit |= 0xfff; + } + else + access_rights &= ~0x8000; + + if (__dpmi_set_segment_base_address (sel, addr) != -1 + && __dpmi_set_descriptor_access_rights (sel, access_rights) != -1 + && __dpmi_set_segment_limit (sel, segment_limit) != -1 + /* W2K silently fails to set the segment limit, leaving + it at zero; this test avoids the resulting crash. */ + && __dpmi_get_segment_limit (sel) >= segment_limit) + movedata (sel, 0, _my_ds (), (unsigned)dest, len); + else + retval = 0; + + __dpmi_free_ldt_descriptor (sel); + } + } + return retval; +} + +/* Get a segment descriptor stored at index IDX in the descriptor + table whose base address is TABLE_BASE. Return the descriptor + type, or -1 if failure. */ +static int +get_descriptor (unsigned long table_base, int idx, void *descr) +{ + unsigned long addr = table_base + idx * 8; /* 8 bytes per entry */ + + if (read_memory_region (addr, descr, 8)) + return (int)((struct seg_descr *)descr)->stype; + return -1; +} + +struct dtr_reg { + unsigned short limit __attribute__((packed)); + unsigned long base __attribute__((packed)); +}; + +/* Display a segment descriptor stored at index IDX in a descriptor + table whose type is TYPE and whose base address is BASE_ADDR. If + FORCE is non-zero, display even invalid descriptors. */ +static void +display_descriptor (unsigned type, unsigned long base_addr, int idx, int force) +{ + struct seg_descr descr; + struct gate_descr gate; + + /* Get the descriptor from the table. */ + if (idx == 0 && type == 0) + puts_filtered ("0x000: null descriptor\n"); + else if (get_descriptor (base_addr, idx, &descr) != -1) + { + /* For each type of descriptor table, this has a bit set if the + corresponding type of selectors is valid in that table. */ + static unsigned allowed_descriptors[] = { + 0xffffdafeL, /* GDT */ + 0x0000c0e0L, /* IDT */ + 0xffffdafaL /* LDT */ + }; + + /* If the program hasn't started yet, assume the debuggee will + have the same CPL as the debugger. */ + int cpl = prog_has_started ? (a_tss.tss_cs & 3) : _my_cs () & 3; + unsigned long limit = (descr.limit1 << 16) | descr.limit0; + + if (descr.present + && (allowed_descriptors[type] & (1 << descr.stype)) != 0) + { + printf_filtered ("0x%03x: ", + type == 1 + ? idx : (idx * 8) | (type ? (cpl | 4) : 0)); + if (descr.page_granular) + limit = (limit << 12) | 0xfff; /* big segment: low 12 bit set */ + if (descr.stype == 1 || descr.stype == 2 || descr.stype == 3 + || descr.stype == 9 || descr.stype == 11 + || (descr.stype >= 16 && descr.stype < 32)) + printf_filtered ("base=0x%02x%02x%04x limit=0x%08lx", + descr.base2, descr.base1, descr.base0, limit); + + switch (descr.stype) + { + case 1: + case 3: + printf_filtered (" 16-bit TSS (task %sactive)", + descr.stype == 3 ? "" : "in"); + break; + case 2: + puts_filtered (" LDT"); + break; + case 4: + memcpy (&gate, &descr, sizeof gate); + printf_filtered ("selector=0x%04x offs=0x%04x%04x", + gate.selector, gate.offset1, gate.offset0); + printf_filtered (" 16-bit Call Gate (params=%d)", + gate.param_count); + break; + case 5: + printf_filtered ("TSS selector=0x%04x", descr.base0); + printfi_filtered (16, "Task Gate"); + break; + case 6: + case 7: + memcpy (&gate, &descr, sizeof gate); + printf_filtered ("selector=0x%04x offs=0x%04x%04x", + gate.selector, gate.offset1, gate.offset0); + printf_filtered (" 16-bit %s Gate", + descr.stype == 6 ? "Interrupt" : "Trap"); + break; + case 9: + case 11: + printf_filtered (" 32-bit TSS (task %sactive)", + descr.stype == 3 ? "" : "in"); + break; + case 12: + memcpy (&gate, &descr, sizeof gate); + printf_filtered ("selector=0x%04x offs=0x%04x%04x", + gate.selector, gate.offset1, gate.offset0); + printf_filtered (" 32-bit Call Gate (params=%d)", + gate.param_count); + break; + case 14: + case 15: + memcpy (&gate, &descr, sizeof gate); + printf_filtered ("selector=0x%04x offs=0x%04x%04x", + gate.selector, gate.offset1, gate.offset0); + printf_filtered (" 32-bit %s Gate", + descr.stype == 14 ? "Interrupt" : "Trap"); + break; + case 16: /* data segments */ + case 17: + case 18: + case 19: + case 20: + case 21: + case 22: + case 23: + printf_filtered (" %s-bit Data (%s Exp-%s%s)", + descr.bit32 ? "32" : "16", + descr.stype & 2 ? "Read/Write," : "Read-Only, ", + descr.stype & 4 ? "down" : "up", + descr.stype & 1 ? "" : ", N.Acc"); + break; + case 24: /* code segments */ + case 25: + case 26: + case 27: + case 28: + case 29: + case 30: + case 31: + printf_filtered (" %s-bit Code (%s, %sConf%s)", + descr.bit32 ? "32" : "16", + descr.stype & 2 ? "Exec/Read" : "Exec-Only", + descr.stype & 4 ? "" : "N.", + descr.stype & 1 ? "" : ", N.Acc"); + break; + default: + printf_filtered ("Unknown type 0x%02x", descr.stype); + break; + } + puts_filtered ("\n"); + } + else if (force) + { + printf_filtered ("0x%03x: ", + type == 1 + ? idx : (idx * 8) | (type ? (cpl | 4) : 0)); + if (!descr.present) + puts_filtered ("Segment not present\n"); + else + printf_filtered ("Segment type 0x%02x is invalid in this table\n", + descr.stype); + } + } + else if (force) + printf_filtered ("0x%03x: Cannot read this descriptor\n", idx); +} + +static void +go32_sldt (char *arg, int from_tty) +{ + struct dtr_reg gdtr; + unsigned short ldtr = 0; + int ldt_idx; + struct seg_descr ldt_descr; + long ldt_entry = -1L; + int cpl = (prog_has_started ? a_tss.tss_cs : _my_cs ()) & 3; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + { + ldt_entry = parse_and_eval_long (arg); + if (ldt_entry < 0 + || (ldt_entry & 4) == 0 + || (ldt_entry & 3) != (cpl & 3)) + error ("Invalid LDT entry 0x%03lx.", (unsigned long)ldt_entry); + } + } + + __asm__ __volatile__ ("sgdt %0" : "=m" (gdtr) : /* no inputs */ ); + __asm__ __volatile__ ("sldt %0" : "=m" (ldtr) : /* no inputs */ ); + ldt_idx = ldtr / 8; + if (ldt_idx == 0) + puts_filtered ("There is no LDT.\n"); + /* LDT's entry in the GDT must have the type LDT, which is 2. */ + else if (get_descriptor (gdtr.base, ldt_idx, &ldt_descr) != 2) + printf_filtered ("LDT is present (at %#x), but unreadable by GDB.\n", + ldt_descr.base0 + | (ldt_descr.base1 << 16) + | (ldt_descr.base2 << 24)); + else + { + unsigned base = + ldt_descr.base0 + | (ldt_descr.base1 << 16) + | (ldt_descr.base2 << 24); + unsigned limit = ldt_descr.limit0 | (ldt_descr.limit1 << 16); + int max_entry; + + if (ldt_descr.page_granular) + /* Page-granular segments must have the low 12 bits of their + limit set. */ + limit = (limit << 12) | 0xfff; + /* LDT cannot have more than 8K 8-byte entries, i.e. more than + 64KB. */ + if (limit > 0xffff) + limit = 0xffff; + + max_entry = (limit + 1) / 8; + + if (ldt_entry >= 0) + { + if (ldt_entry > limit) + error ("Invalid LDT entry %#lx: outside valid limits [0..%#x]", + (unsigned long)ldt_entry, limit); + + display_descriptor (ldt_descr.stype, base, ldt_entry / 8, 1); + } + else + { + int i; + + for (i = 0; i < max_entry; i++) + display_descriptor (ldt_descr.stype, base, i, 0); + } + } +} + +static void +go32_sgdt (char *arg, int from_tty) +{ + struct dtr_reg gdtr; + long gdt_entry = -1L; + int max_entry; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + { + gdt_entry = parse_and_eval_long (arg); + if (gdt_entry < 0 || (gdt_entry & 7) != 0) + error ("Invalid GDT entry 0x%03lx: not an integral multiple of 8.", + (unsigned long)gdt_entry); + } + } + + __asm__ __volatile__ ("sgdt %0" : "=m" (gdtr) : /* no inputs */ ); + max_entry = (gdtr.limit + 1) / 8; + + if (gdt_entry >= 0) + { + if (gdt_entry > gdtr.limit) + error ("Invalid GDT entry %#lx: outside valid limits [0..%#x]", + (unsigned long)gdt_entry, gdtr.limit); + + display_descriptor (0, gdtr.base, gdt_entry / 8, 1); + } + else + { + int i; + + for (i = 0; i < max_entry; i++) + display_descriptor (0, gdtr.base, i, 0); + } +} + +static void +go32_sidt (char *arg, int from_tty) +{ + struct dtr_reg idtr; + long idt_entry = -1L; + int max_entry; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + { + idt_entry = parse_and_eval_long (arg); + if (idt_entry < 0) + error ("Invalid (negative) IDT entry %ld.", idt_entry); + } + } + + __asm__ __volatile__ ("sidt %0" : "=m" (idtr) : /* no inputs */ ); + max_entry = (idtr.limit + 1) / 8; + if (max_entry > 0x100) /* no more than 256 entries */ + max_entry = 0x100; + + if (idt_entry >= 0) + { + if (idt_entry > idtr.limit) + error ("Invalid IDT entry %#lx: outside valid limits [0..%#x]", + (unsigned long)idt_entry, idtr.limit); + + display_descriptor (1, idtr.base, idt_entry, 1); + } + else + { + int i; + + for (i = 0; i < max_entry; i++) + display_descriptor (1, idtr.base, i, 0); + } +} + +/* Cached linear address of the base of the page directory. For + now, available only under CWSDPMI. Code based on ideas and + suggestions from Charles Sandmann <sandmann@clio.rice.edu>. */ +static unsigned long pdbr; + +static unsigned long +get_cr3 (void) +{ + unsigned offset; + unsigned taskreg; + unsigned long taskbase, cr3; + struct dtr_reg gdtr; + + if (pdbr > 0 && pdbr <= 0xfffff) + return pdbr; + + /* Get the linear address of GDT and the Task Register. */ + __asm__ __volatile__ ("sgdt %0" : "=m" (gdtr) : /* no inputs */ ); + __asm__ __volatile__ ("str %0" : "=m" (taskreg) : /* no inputs */ ); + + /* Task Register is a segment selector for the TSS of the current + task. Therefore, it can be used as an index into the GDT to get + at the segment descriptor for the TSS. To get the index, reset + the low 3 bits of the selector (which give the CPL). Add 2 to the + offset to point to the 3 low bytes of the base address. */ + offset = gdtr.base + (taskreg & 0xfff8) + 2; + + + /* CWSDPMI's task base is always under the 1MB mark. */ + if (offset > 0xfffff) + return 0; + + _farsetsel (_dos_ds); + taskbase = _farnspeekl (offset) & 0xffffffU; + taskbase += _farnspeekl (offset + 2) & 0xff000000U; + if (taskbase > 0xfffff) + return 0; + + /* CR3 (a.k.a. PDBR, the Page Directory Base Register) is stored at + offset 1Ch in the TSS. */ + cr3 = _farnspeekl (taskbase + 0x1c) & ~0xfff; + if (cr3 > 0xfffff) + { +#if 0 /* not fullly supported yet */ + /* The Page Directory is in UMBs. In that case, CWSDPMI puts + the first Page Table right below the Page Directory. Thus, + the first Page Table's entry for its own address and the Page + Directory entry for that Page Table will hold the same + physical address. The loop below searches the entire UMB + range of addresses for such an occurence. */ + unsigned long addr, pte_idx; + + for (addr = 0xb0000, pte_idx = 0xb0; + pte_idx < 0xff; + addr += 0x1000, pte_idx++) + { + if (((_farnspeekl (addr + 4 * pte_idx) & 0xfffff027) == + (_farnspeekl (addr + 0x1000) & 0xfffff027)) + && ((_farnspeekl (addr + 4 * pte_idx + 4) & 0xfffff000) == cr3)) + { + cr3 = addr + 0x1000; + break; + } + } +#endif + + if (cr3 > 0xfffff) + cr3 = 0; + } + + return cr3; +} + +/* Return the N'th Page Directory entry. */ +static unsigned long +get_pde (int n) +{ + unsigned long pde = 0; + + if (pdbr && n >= 0 && n < 1024) + { + pde = _farpeekl (_dos_ds, pdbr + 4*n); + } + return pde; +} + +/* Return the N'th entry of the Page Table whose Page Directory entry + is PDE. */ +static unsigned long +get_pte (unsigned long pde, int n) +{ + unsigned long pte = 0; + + /* pde & 0x80 tests the 4MB page bit. We don't support 4MB + page tables, for now. */ + if ((pde & 1) && !(pde & 0x80) && n >= 0 && n < 1024) + { + pde &= ~0xfff; /* clear non-address bits */ + pte = _farpeekl (_dos_ds, pde + 4*n); + } + return pte; +} + +/* Display a Page Directory or Page Table entry. IS_DIR, if non-zero, + says this is a Page Directory entry. If FORCE is non-zero, display + the entry even if its Present flag is off. OFF is the offset of the + address from the page's base address. */ +static void +display_ptable_entry (unsigned long entry, int is_dir, int force, unsigned off) +{ + if ((entry & 1) != 0) + { + printf_filtered ("Base=0x%05lx000", entry >> 12); + if ((entry & 0x100) && !is_dir) + puts_filtered (" Global"); + if ((entry & 0x40) && !is_dir) + puts_filtered (" Dirty"); + printf_filtered (" %sAcc.", (entry & 0x20) ? "" : "Not-"); + printf_filtered (" %sCached", (entry & 0x10) ? "" : "Not-"); + printf_filtered (" Write-%s", (entry & 8) ? "Thru" : "Back"); + printf_filtered (" %s", (entry & 4) ? "Usr" : "Sup"); + printf_filtered (" Read-%s", (entry & 2) ? "Write" : "Only"); + if (off) + printf_filtered (" +0x%x", off); + puts_filtered ("\n"); + } + else if (force) + printf_filtered ("Page%s not present or not supported; value=0x%lx.\n", + is_dir ? " Table" : "", entry >> 1); +} + +static void +go32_pde (char *arg, int from_tty) +{ + long pde_idx = -1, i; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + { + pde_idx = parse_and_eval_long (arg); + if (pde_idx < 0 || pde_idx >= 1024) + error ("Entry %ld is outside valid limits [0..1023].", pde_idx); + } + } + + pdbr = get_cr3 (); + if (!pdbr) + puts_filtered ("Access to Page Directories is not supported on this system.\n"); + else if (pde_idx >= 0) + display_ptable_entry (get_pde (pde_idx), 1, 1, 0); + else + for (i = 0; i < 1024; i++) + display_ptable_entry (get_pde (i), 1, 0, 0); +} + +/* A helper function to display entries in a Page Table pointed to by + the N'th entry in the Page Directory. If FORCE is non-zero, say + something even if the Page Table is not accessible. */ +static void +display_page_table (long n, int force) +{ + unsigned long pde = get_pde (n); + + if ((pde & 1) != 0) + { + int i; + + printf_filtered ("Page Table pointed to by Page Directory entry 0x%lx:\n", n); + for (i = 0; i < 1024; i++) + display_ptable_entry (get_pte (pde, i), 0, 0, 0); + puts_filtered ("\n"); + } + else if (force) + printf_filtered ("Page Table not present; value=0x%lx.\n", pde >> 1); +} + +static void +go32_pte (char *arg, int from_tty) +{ + long pde_idx = -1L, i; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + { + pde_idx = parse_and_eval_long (arg); + if (pde_idx < 0 || pde_idx >= 1024) + error ("Entry %ld is outside valid limits [0..1023].", pde_idx); + } + } + + pdbr = get_cr3 (); + if (!pdbr) + puts_filtered ("Access to Page Tables is not supported on this system.\n"); + else if (pde_idx >= 0) + display_page_table (pde_idx, 1); + else + for (i = 0; i < 1024; i++) + display_page_table (i, 0); +} + +static void +go32_pte_for_address (char *arg, int from_tty) +{ + CORE_ADDR addr = 0, i; + + if (arg && *arg) + { + while (*arg && isspace(*arg)) + arg++; + + if (*arg) + addr = parse_and_eval_address (arg); + } + if (!addr) + error_no_arg ("linear address"); + + pdbr = get_cr3 (); + if (!pdbr) + puts_filtered ("Access to Page Tables is not supported on this system.\n"); + else + { + int pde_idx = (addr >> 22) & 0x3ff; + int pte_idx = (addr >> 12) & 0x3ff; + unsigned offs = addr & 0xfff; + + printf_filtered ("Page Table entry for address 0x%llx:\n", + (unsigned long long)addr); + display_ptable_entry (get_pte (get_pde (pde_idx), pte_idx), 0, 1, offs); + } +} + +static struct cmd_list_element *info_dos_cmdlist = NULL; + +static void +go32_info_dos_command (char *args, int from_tty) +{ + help_list (info_dos_cmdlist, "info dos ", class_info, gdb_stdout); +} + +void +_initialize_go32_nat (void) +{ + init_go32_ops (); + add_target (&go32_ops); + + add_prefix_cmd ("dos", class_info, go32_info_dos_command, + "Print information specific to DJGPP (aka MS-DOS) debugging.", + &info_dos_cmdlist, "info dos ", 0, &infolist); + + add_cmd ("sysinfo", class_info, go32_sysinfo, + "Display information about the target system, including CPU, OS, DPMI, etc.", + &info_dos_cmdlist); + add_cmd ("ldt", class_info, go32_sldt, + "Display entries in the LDT (Local Descriptor Table).\n" + "Entry number (an expression) as an argument means display only that entry.", + &info_dos_cmdlist); + add_cmd ("gdt", class_info, go32_sgdt, + "Display entries in the GDT (Global Descriptor Table).\n" + "Entry number (an expression) as an argument means display only that entry.", + &info_dos_cmdlist); + add_cmd ("idt", class_info, go32_sidt, + "Display entries in the IDT (Interrupt Descriptor Table).\n" + "Entry number (an expression) as an argument means display only that entry.", + &info_dos_cmdlist); + add_cmd ("pde", class_info, go32_pde, + "Display entries in the Page Directory.\n" + "Entry number (an expression) as an argument means display only that entry.", + &info_dos_cmdlist); + add_cmd ("pte", class_info, go32_pte, + "Display entries in Page Tables.\n" + "Entry number (an expression) as an argument means display only entries\n" + "from the Page Table pointed to by the specified Page Directory entry.", + &info_dos_cmdlist); + add_cmd ("address-pte", class_info, go32_pte_for_address, + "Display a Page Table entry for a linear address.\n" + "The address argument must be a linear address, after adding to\n" + "it the base address of the appropriate segment.\n" + "The base address of variables and functions in the debuggee's data\n" + "or code segment is stored in the variable __djgpp_base_address,\n" + "so use `__djgpp_base_address + (char *)&var' as the argument.\n" + "For other segments, look up their base address in the output of\n" + "the `info dos ldt' command.", + &info_dos_cmdlist); +} + +pid_t +tcgetpgrp (int fd) +{ + if (isatty (fd)) + return SOME_PID; + errno = ENOTTY; + return -1; +} + +int +tcsetpgrp (int fd, pid_t pgid) +{ + if (isatty (fd) && pgid == SOME_PID) + return 0; + errno = pgid == SOME_PID ? ENOTTY : ENOSYS; + return -1; +} |
