xref: /linux/arch/m68k/include/asm/user.h (revision 49148020bcb6910ce71417bd990a5ce7017f9bd3)
1*49148020SSam Ravnborg #ifndef _M68K_USER_H
2*49148020SSam Ravnborg #define _M68K_USER_H
3*49148020SSam Ravnborg 
4*49148020SSam Ravnborg /* Core file format: The core file is written in such a way that gdb
5*49148020SSam Ravnborg    can understand it and provide useful information to the user (under
6*49148020SSam Ravnborg    linux we use the 'trad-core' bfd).  There are quite a number of
7*49148020SSam Ravnborg    obstacles to being able to view the contents of the floating point
8*49148020SSam Ravnborg    registers, and until these are solved you will not be able to view the
9*49148020SSam Ravnborg    contents of them.  Actually, you can read in the core file and look at
10*49148020SSam Ravnborg    the contents of the user struct to find out what the floating point
11*49148020SSam Ravnborg    registers contain.
12*49148020SSam Ravnborg    The actual file contents are as follows:
13*49148020SSam Ravnborg    UPAGE: 1 page consisting of a user struct that tells gdb what is present
14*49148020SSam Ravnborg    in the file.  Directly after this is a copy of the task_struct, which
15*49148020SSam Ravnborg    is currently not used by gdb, but it may come in useful at some point.
16*49148020SSam Ravnborg    All of the registers are stored as part of the upage.  The upage should
17*49148020SSam Ravnborg    always be only one page.
18*49148020SSam Ravnborg    DATA: The data area is stored.  We use current->end_text to
19*49148020SSam Ravnborg    current->brk to pick up all of the user variables, plus any memory
20*49148020SSam Ravnborg    that may have been malloced.  No attempt is made to determine if a page
21*49148020SSam Ravnborg    is demand-zero or if a page is totally unused, we just cover the entire
22*49148020SSam Ravnborg    range.  All of the addresses are rounded in such a way that an integral
23*49148020SSam Ravnborg    number of pages is written.
24*49148020SSam Ravnborg    STACK: We need the stack information in order to get a meaningful
25*49148020SSam Ravnborg    backtrace.  We need to write the data from (esp) to
26*49148020SSam Ravnborg    current->start_stack, so we round each of these off in order to be able
27*49148020SSam Ravnborg    to write an integer number of pages.
28*49148020SSam Ravnborg    The minimum core file size is 3 pages, or 12288 bytes.
29*49148020SSam Ravnborg */
30*49148020SSam Ravnborg 
31*49148020SSam Ravnborg struct user_m68kfp_struct {
32*49148020SSam Ravnborg 	unsigned long  fpregs[8*3];	/* fp0-fp7 registers */
33*49148020SSam Ravnborg 	unsigned long  fpcntl[3];	/* fp control regs */
34*49148020SSam Ravnborg };
35*49148020SSam Ravnborg 
36*49148020SSam Ravnborg /* This is the old layout of "struct pt_regs" as of Linux 1.x, and
37*49148020SSam Ravnborg    is still the layout used by user (the new pt_regs doesn't have
38*49148020SSam Ravnborg    all registers). */
39*49148020SSam Ravnborg struct user_regs_struct {
40*49148020SSam Ravnborg 	long d1,d2,d3,d4,d5,d6,d7;
41*49148020SSam Ravnborg 	long a0,a1,a2,a3,a4,a5,a6;
42*49148020SSam Ravnborg 	long d0;
43*49148020SSam Ravnborg 	long usp;
44*49148020SSam Ravnborg 	long orig_d0;
45*49148020SSam Ravnborg 	short stkadj;
46*49148020SSam Ravnborg 	short sr;
47*49148020SSam Ravnborg 	long pc;
48*49148020SSam Ravnborg 	short fmtvec;
49*49148020SSam Ravnborg 	short __fill;
50*49148020SSam Ravnborg };
51*49148020SSam Ravnborg 
52*49148020SSam Ravnborg 
53*49148020SSam Ravnborg /* When the kernel dumps core, it starts by dumping the user struct -
54*49148020SSam Ravnborg    this will be used by gdb to figure out where the data and stack segments
55*49148020SSam Ravnborg    are within the file, and what virtual addresses to use. */
56*49148020SSam Ravnborg struct user{
57*49148020SSam Ravnborg /* We start with the registers, to mimic the way that "memory" is returned
58*49148020SSam Ravnborg    from the ptrace(3,...) function.  */
59*49148020SSam Ravnborg   struct user_regs_struct regs;	/* Where the registers are actually stored */
60*49148020SSam Ravnborg /* ptrace does not yet supply these.  Someday.... */
61*49148020SSam Ravnborg   int u_fpvalid;		/* True if math co-processor being used. */
62*49148020SSam Ravnborg                                 /* for this mess. Not yet used. */
63*49148020SSam Ravnborg   struct user_m68kfp_struct m68kfp; /* Math Co-processor registers. */
64*49148020SSam Ravnborg /* The rest of this junk is to help gdb figure out what goes where */
65*49148020SSam Ravnborg   unsigned long int u_tsize;	/* Text segment size (pages). */
66*49148020SSam Ravnborg   unsigned long int u_dsize;	/* Data segment size (pages). */
67*49148020SSam Ravnborg   unsigned long int u_ssize;	/* Stack segment size (pages). */
68*49148020SSam Ravnborg   unsigned long start_code;     /* Starting virtual address of text. */
69*49148020SSam Ravnborg   unsigned long start_stack;	/* Starting virtual address of stack area.
70*49148020SSam Ravnborg 				   This is actually the bottom of the stack,
71*49148020SSam Ravnborg 				   the top of the stack is always found in the
72*49148020SSam Ravnborg 				   esp register.  */
73*49148020SSam Ravnborg   long int signal;		/* Signal that caused the core dump. */
74*49148020SSam Ravnborg   int reserved;			/* No longer used */
75*49148020SSam Ravnborg   unsigned long u_ar0;		/* Used by gdb to help find the values for */
76*49148020SSam Ravnborg 				/* the registers. */
77*49148020SSam Ravnborg   struct user_m68kfp_struct* u_fpstate;	/* Math Co-processor pointer. */
78*49148020SSam Ravnborg   unsigned long magic;		/* To uniquely identify a core file */
79*49148020SSam Ravnborg   char u_comm[32];		/* User command that was responsible */
80*49148020SSam Ravnborg };
81*49148020SSam Ravnborg #define NBPG 4096
82*49148020SSam Ravnborg #define UPAGES 1
83*49148020SSam Ravnborg #define HOST_TEXT_START_ADDR (u.start_code)
84*49148020SSam Ravnborg #define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
85*49148020SSam Ravnborg 
86*49148020SSam Ravnborg #endif
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