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Diffstat (limited to 'gdb/standalone.c')
| -rw-r--r-- | gdb/standalone.c | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/gdb/standalone.c b/gdb/standalone.c new file mode 100644 index 0000000..94adf64 --- /dev/null +++ b/gdb/standalone.c @@ -0,0 +1,605 @@ +/* Interface to bare machine for GDB running as kernel debugger. + Copyright (C) 1986 Free Software Foundation, Inc. + +GDB is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY. No author or distributor accepts responsibility to anyone +for the consequences of using it or for whether it serves any +particular purpose or works at all, unless he says so in writing. +Refer to the GDB General Public License for full details. + +Everyone is granted permission to copy, modify and redistribute GDB, +but only under the conditions described in the GDB General Public +License. A copy of this license is supposed to have been given to you +along with GDB so you can know your rights and responsibilities. It +should be in a file named COPYING. Among other things, the copyright +notice and this notice must be preserved on all copies. + +In other words, go ahead and share GDB, but don't try to stop +anyone else from sharing it farther. Help stamp out software hoarding! +*/ + +#include <stdio.h> +#include <sys/ioctl.h> +#include <signal.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> + +#if defined (SIGTSTP) && defined (SIGIO) +#include <sys/time.h> +#include <sys/resource.h> +#endif /* SIGTSTP and SIGIO defined (must be 4.2) */ + +#include "defs.h" +#include "initialize.h" +#include "param.h" +#include "symtab.h" +#include "frame.h" +#include "inferior.h" +#include "wait.h" + +START_FILE + +/* Random system calls, mostly no-ops to prevent link problems */ + +ioctl (desc, code, arg) +{} + +int (* signal ()) () +{} + +kill () +{} + +getpid () +{ + return 0; +} + +sigsetmask () +{} + +chdir () +{} + +char * +getwd (buf) + char *buf; +{ + buf[0] = '/'; + buf[1] = 0; + return buf; +} + +/* Used to check for existence of .gdbinit. Say no. */ + +access () +{ + return -1; +} + +exit () +{ + error ("Fatal error; restarting."); +} + +/* Reading "files". The contents of some files are written into kdb's + data area before it is run. These files are used to contain the + symbol table for kdb to load, and the source files (in case the + kdb user wants to print them). The symbols are stored in a file + named "kdb-symbols" in a.out format (except that all the text and + data have been stripped to save room). + + The files are stored in the following format: + int number of bytes of data for this file, including these four. + char[] name of the file, ending with a null. + padding to multiple of 4 boundary. + char[] file contents. The length can be deduced from what was + specified before. There is no terminating null here. + + If the int at the front is zero, it means there are no more files. + + Opening a file in kdb returns a nonzero value to indicate success, + but the value does not matter. Only one file can be open, and only + for reading. All the primitives for input from the file know + which file is open and ignore what is specified for the descriptor + or for the stdio stream. + + Input with fgetc can be done either on the file that is open + or on stdin (which reads from the terminal through tty_input () */ + +/* Address of data for the files stored in format described above. */ +char *files_start; + +/* The file stream currently open: */ + +char *sourcebeg; /* beginning of contents */ +int sourcesize; /* size of contents */ +char *sourceptr; /* current read pointer */ +int sourceleft; /* number of bytes to eof */ + +/* "descriptor" for the file now open. + Incremented at each close. + If specified descriptor does not match this, + it means the program is trying to use a closed descriptor. + We report an error for that. */ + +int sourcedesc; + +open (filename, modes) + char *filename; + int modes; +{ + register char *next; + extern int errno; + + if (modes) + { + errno = EROFS; + return -1; + } + + if (sourceptr) + { + errno = EMFILE; + return -1; + } + + for (next - files_start; * (int *) next; + next += * (int *) next) + { + if (!strcmp (next + 4, filename)) + { + sourcebeg = next + 4 + strlen (next + 4) + 1; + sourcebeg = (char *) (((int) sourcebeg + 3) & (-4)); + sourceptr = sourcebeg; + sourcesize = next + * (int *) next - sourceptr; + sourceleft = sourcesize; + return sourcedesc; + } + } + return 0; +} + +close (desc) + int desc; +{ + sourceptr = 0; + sourcedesc++; + /* Don't let sourcedesc get big enough to be confused with stdin. */ + if (sourcedesc == 100) + sourcedesc = 5; +} + +FILE * +fopen (filename, modes) + char *filename; + char *modes; +{ + return (FILE *) open (filename, *modes == 'w'); +} + +FILE * +fdopen (desc) + int desc; +{ + return (FILE *) desc; +} + +fclose (desc) + int desc; +{ + close (desc); +} + +fstat (desc, statbuf) + struct stat *statbuf; +{ + extern int errno; + + if (desc != sourcedesc) + { + errno = EBADF; + return -1; + } + statbuf->st_size = sourcesize; +} + +myread (desc, destptr, size, filename) + int desc; + char *destptr; + int size; + char *filename; +{ + int len = min (sourceleft, size); + extern int errno; + + if (desc != sourcedesc) + { + errno = EBADF; + return -1; + } + + bcopy (sourceptr, destptr, len); + sourceleft -= len; + return len; +} + +int +fread (bufp, numelts, eltsize, stream) +{ + register int elts = min (numelts, sourceleft / eltsize); + register int len = elts * eltsize; + extern int errno; + + if (stream != sourcedesc) + { + errno = EBADF; + return -1; + } + + bcopy (sourceptr, bufp, len); + sourceleft -= len; + return elts; +} + +int +fgetc (desc) + int desc; +{ + extern int errno; + + if (desc == (int) stdin) + return tty_input (); + + if (desc != sourcedesc) + { + errno = EBADF; + return -1; + } + + if (sourceleft-- <= 0) + return EOF; + return *sourceptr++; +} + +lseek (desc, pos) + int desc; + int pos; +{ + extern int errno; + + if (desc != sourcedesc) + { + errno = EBADF; + return -1; + } + + if (pos < 0 || pos > sourcesize) + { + errno = EINVAL; + return -1; + } + + sourceptr = sourcebeg + pos; + sourceleft = sourcesize - pos; +} + +/* Output in kdb can go only to the terminal, so the stream + specified may be ignored. */ + +printf (a1, a2, a3, a4, a5, a6, a7, a8, a9) +{ + char buffer[1024]; + sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9); + display_string (buffer); +} + +fprintf (ign, a1, a2, a3, a4, a5, a6, a7, a8, a9) +{ + char buffer[1024]; + sprintf (buffer, a1, a2, a3, a4, a5, a6, a7, a8, a9); + display_string (buffer); +} + +fwrite (buf, numelts, size, stream) + register char *buf; + int numelts, size; +{ + register int i = numelts * size; + while (i-- > 0) + fputc (*buf++, stream); +} + +fputc (c, ign) +{ + char buf[2]; + buf[0] = c; + buf[1] = 0; + display_string (buf); +} + +/* sprintf refers to this, but loading this from the + library would cause fflush to be loaded from it too. + In fact there should be no need to call this (I hope). */ + +_flsbuf () +{ + error ("_flsbuf was actually called."); +} + +fflush (ign) +{ +} + +/* Entries into core and inflow, needed only to make things link ok. */ + +exec_file_command () +{} + +core_file_command () +{} + +char * +get_exec_file () +{ + /* Makes one printout look reasonable; value does not matter otherwise. */ + return "run"; +} + +have_core_file_p () +{ + return 0; +} + +kill_command () +{ + inferior_pid = 0; +} + +terminal_inferior () +{} + +terminal_ours () +{} + +terminal_init_inferior () +{} + +write_inferior_register () +{} + +read_inferior_register () +{} + +read_memory (memaddr, myaddr, len) + CORE_ADDR memaddr; + char *myaddr; + int len; +{ + bcopy (memaddr, myaddr, len); +} + +/* Always return 0 indicating success. */ + +write_memory (memaddr, myaddr, len) + CORE_ADDR memaddr; + char *myaddr; + int len; +{ + bcopy (myaddr, memaddr, len); + return 0; +} + +static REGISTER_TYPE saved_regs[NUM_REGS]; + +REGISTER_TYPE +read_register (regno) + int regno; +{ + if (regno < 0 || regno >= NUM_REGS) + error ("Register number %d out of range.", regno); + return saved_regs[regno]; +} + +void +write_register (regno, value) + int regno; + REGISTER_TYPE value; +{ + if (regno < 0 || regno >= NUM_REGS) + error ("Register number %d out of range.", regno); + saved_regs[regno] = value; +} + +/* System calls needed in relation to running the "inferior". */ + +vfork () +{ + /* Just appear to "succeed". Say the inferior's pid is 1. */ + return 1; +} + +/* These are called by code that normally runs in the inferior + that has just been forked. That code never runs, when standalone, + and these definitions are so it will link without errors. */ + +ptrace () +{} + +setpgrp () +{} + +execle () +{} + +_exit () +{} + +/* Malloc calls these. */ + +malloc_warning (str) + char *str; +{ + printf ("\n%s.\n\n", str); +} + +char *next_free; +char *memory_limit; + +char * +sbrk (amount) + int amount; +{ + if (next_free + amount > memory_limit) + return (char *) -1; + next_free += amount; + return next_free - amount; +} + +/* Various ways malloc might ask where end of memory is. */ + +char * +ulimit () +{ + return memory_limit; +} + +int +vlimit () +{ + return memory_limit - next_free; +} + +getrlimit (addr) + struct rlimit *addr; +{ + addr->rlim_cur = memory_limit - next_free; +} + +/* Context switching to and from program being debugged. */ + +/* GDB calls here to run the user program. + The frame pointer for this function is saved in + gdb_stack by save_frame_pointer; then we restore + all of the user program's registers, including PC and PS. */ + +static int fault_code; +static REGISTER_TYPE gdb_stack; + +resume () +{ + REGISTER_TYPE restore[NUM_REGS]; + + PUSH_FRAME_PTR; + save_frame_pointer (); + + bcopy (saved_regs, restore, sizeof restore); + POP_REGISTERS; + /* Control does not drop through here! */ +} + +save_frame_pointer (val) + CORE_ADDR val; +{ + gdb_stack = val; +} + +/* Fault handlers call here, running in the user program stack. + They must first push a fault code, + old PC, old PS, and any other info about the fault. + The exact format is machine-dependent and is known only + in the definition of PUSH_REGISTERS. */ + +fault () +{ + /* Transfer all registers and fault code to the stack + in canonical order: registers in order of GDB register number, + followed by fault code. */ + PUSH_REGISTERS; + + /* Transfer them to saved_regs and fault_code. */ + save_registers (); + + restore_gdb (); + /* Control does not reach here */ +} + +restore_gdb () +{ + CORE_ADDR new_fp = gdb_stack; + /* Switch to GDB's stack */ + POP_FRAME_PTR; + /* Return from the function `resume'. */ +} + +/* Assuming register contents and fault code have been pushed on the stack as + arguments to this function, copy them into the standard place + for the program's registers while GDB is running. */ + +save_registers (firstreg) + int firstreg; +{ + bcopy (&firstreg, saved_regs, sizeof saved_regs); + fault_code = (&firstreg)[NUM_REGS]; +} + +/* Store into the structure such as `wait' would return + the information on why the program faulted, + converted into a machine-independent signal number. */ + +static int fault_table[] = FAULT_TABLE; + +int +wait (w) + WAITTYPE *w; +{ + WSETSTOP (*w, fault_table[fault_code / FAULT_CODE_UNITS]); + return inferior_pid; +} + +/* Allocate a big space in which files for kdb to read will be stored. + Whatever is left is where malloc can allocate storage. + + Initialize it, so that there will be space in the executable file + for it. Then the files can be put into kdb by writing them into + kdb's executable file. */ + +/* The default size is as much space as we expect to be available + for kdb to use! */ + +#ifndef HEAP_SIZE +#define HEAP_SIZE 400000 +#endif + +char heap[HEAP_SIZE] = {0}; + +#ifndef STACK_SIZE +#define STACK_SIZE 100000 +#endif + +int kdb_stack_beg[STACK_SIZE / sizeof (int)]; +int kdb_stack_end; + +static +initialize () +{ + register char *next; + + /* Find start of data on files. */ + + files_start = heap; + + /* Find the end of the data on files. */ + + for (next - files_start; * (int *) next; + next += * (int *) next) + {} + + /* That is where free storage starts for sbrk to give out. */ + next_free = next; + + memory_limit = heap + sizeof heap; +} + +END_FILE |