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[glibc.git] / hurd / hurdstartup.c
blob0c607ba3fb0950496ae88bf5070cd4cba52ba071
1 /* Initial program startup for running under the GNU Hurd.
2 Copyright (C) 1991,92,93,94,95,96,97,98,2002 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <stdlib.h>
22 #include <stdio.h>
23 #include <string.h>
24 #include <hurd.h>
25 #include <hurd/exec_startup.h>
26 #include <sysdep.h>
27 #include <hurd/threadvar.h>
28 #include <unistd.h>
29 #include <elf.h>
30 #include <set-hooks.h>
31 #include "hurdstartup.h"
32 #include <argz.h>
34 mach_port_t *_hurd_init_dtable;
35 mach_msg_type_number_t _hurd_init_dtablesize;
37 extern void __mach_init (void);
39 /* Entry point. This is the first thing in the text segment.
41 The exec server started the initial thread in our task with this spot the
42 PC, and a stack that is presumably big enough. We do basic Mach
43 initialization so mig-generated stubs work, and then do an exec_startup
44 RPC on our bootstrap port, to which the exec server responds with the
45 information passed in the exec call, as well as our original bootstrap
46 port, and the base address and size of the preallocated stack.
48 If using cthreads, we are given a new stack by cthreads initialization and
49 deallocate the stack set up by the exec server. On the new stack we call
50 `start1' (above) to do the rest of the startup work. Since the stack may
51 disappear out from under us in a machine-dependent way, we use a pile of
52 static variables to communicate the information from exec_startup to start1.
53 This is unfortunate but preferable to machine-dependent frobnication to copy
54 the state from the old stack to the new one. */
57 void
58 _hurd_startup (void **argptr, void (*main) (intptr_t *data))
60 error_t err;
61 mach_port_t in_bootstrap;
62 char *args, *env;
63 mach_msg_type_number_t argslen, envlen;
64 struct hurd_startup_data data;
65 char **argv, **envp;
66 int argc, envc;
67 intptr_t *argcptr;
68 vm_address_t addr;
70 /* Attempt to map page zero redzoned before we receive any RPC
71 data that might get allocated there. We can ignore errors. */
72 addr = 0;
73 __vm_map (__mach_task_self (),
74 &addr, __vm_page_size, 0, 0, MACH_PORT_NULL, 0, 1,
75 VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_COPY);
77 if (err = __task_get_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT,
78 &in_bootstrap))
79 LOSE;
81 if (in_bootstrap != MACH_PORT_NULL)
83 /* Call the exec server on our bootstrap port and
84 get all our standard information from it. */
86 argslen = envlen = 0;
87 data.dtablesize = data.portarraysize = data.intarraysize = 0;
89 err = __exec_startup_get_info (in_bootstrap,
90 &data.user_entry,
91 &data.phdr, &data.phdrsz,
92 &data.stack_base, &data.stack_size,
93 &data.flags,
94 &args, &argslen,
95 &env, &envlen,
96 &data.dtable, &data.dtablesize,
97 &data.portarray, &data.portarraysize,
98 &data.intarray, &data.intarraysize);
99 __mach_port_deallocate (__mach_task_self (), in_bootstrap);
102 if (err || in_bootstrap == MACH_PORT_NULL || (data.flags & EXEC_STACK_ARGS))
104 /* Either we have no bootstrap port, or the RPC to the exec server
105 failed, or whoever started us up passed the flag saying args are
106 on the stack. Try to snarf the args in the canonical Mach way.
107 Hopefully either they will be on the stack as expected, or the
108 stack will be zeros so we don't crash. */
110 argcptr = (intptr_t *) argptr;
111 argc = argcptr[0];
112 argv = (char **) &argcptr[1];
113 envp = &argv[argc + 1];
114 envc = 0;
115 while (envp[envc])
116 ++envc;
118 else
120 /* Turn the block of null-separated strings we were passed for the
121 arguments and environment into vectors of pointers to strings. */
123 /* Count up the arguments so we can allocate ARGV. */
124 argc = __argz_count (args, argslen);
125 /* Count up the environment variables so we can allocate ENVP. */
126 envc = __argz_count (env, envlen);
128 /* There were some arguments. Allocate space for the vectors of
129 pointers and fill them in. We allocate the space for the
130 environment pointers immediately after the argv pointers because
131 the ELF ABI will expect it. */
132 argcptr = __alloca (sizeof (intptr_t) +
133 (argc + 1 + envc + 1) * sizeof (char *) +
134 sizeof (struct hurd_startup_data));
135 *argcptr = argc;
136 argv = (void *) (argcptr + 1);
137 __argz_extract (args, argslen, argv);
139 /* There was some environment. */
140 envp = &argv[argc + 1];
141 __argz_extract (env, envlen, envp);
144 if (err || in_bootstrap == MACH_PORT_NULL)
146 /* Either we have no bootstrap port, or the RPC to the exec server
147 failed. Set all our other variables to have empty information. */
149 data.flags = 0;
150 args = env = NULL;
151 argslen = envlen = 0;
152 data.dtable = NULL;
153 data.dtablesize = 0;
154 data.portarray = NULL;
155 data.portarraysize = 0;
156 data.intarray = NULL;
157 data.intarraysize = 0;
159 else if ((void *) &envp[envc + 1] == argv[0])
161 /* The arguments arrived on the stack from the kernel, but our
162 protocol requires some space after them for a `struct
163 hurd_startup_data'. Move them. */
164 struct
166 intptr_t count;
167 char *argv[argc + 1];
168 char *envp[envc + 1];
169 struct hurd_startup_data data;
170 } *args = alloca (sizeof *args);
171 if ((void *) &args[1] == (void *) argcptr)
172 args = alloca (-((char *) &args->data - (char *) args));
173 memmove (args, argcptr, (char *) &args->data - (char *) args);
174 argcptr = (void *) args;
175 argv = args->argv;
176 envp = args->envp;
180 struct hurd_startup_data *d = (void *) &envp[envc + 1];
182 if ((void *) d != argv[0])
184 *d = data;
185 _hurd_init_dtable = d->dtable;
186 _hurd_init_dtablesize = d->dtablesize;
189 (*main) (argcptr);
192 /* Should never get here. */
193 LOSE;
194 abort ();