freebsd-dev/sys/boot/i386/libi386/aout_freebsd.c
Mike Smith c2f9d95de5 This is the new unified bootstrap, sometimes known previously as the
'three-stage' bootstrap.
There are a number of caveats with the code in its current state:
 - The i386 bootstrap only supports booting from a floppy.
 - The kernel and kld do not yet know how to deal with the extended
   information and module summary passed in.
 - PnP-based autodetection and demand loading of modules is not implemented.
 - i386 ELF kernel loading is not ready yet.
 - The i386 bootstrap is loaded via an ugly blockmap.

On the alpha, both net- and disk-booting (SRM console machines only) is
supported.  No blockmaps are used by this code.

Obtained from:	Parts from the NetBSD/i386 standalone bootstrap.
1998-08-21 03:17:42 +00:00

275 lines
8.1 KiB
C

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/imgact_aout.h>
#include <sys/reboot.h>
#include <string.h>
#include <machine/bootinfo.h>
#include <stand.h>
#include "bootstrap.h"
#include "libi386.h"
struct aout_kernel_module
{
struct loaded_module m;
vm_offset_t m_entry; /* module entrypoint */
struct bootinfo m_bi; /* legacy bootinfo */
};
static int aout_loadmodule(char *filename, vm_offset_t dest, struct loaded_module **result);
static int aout_exec(struct loaded_module *amp);
struct module_format i386_aout = { MF_AOUT, aout_loadmodule, aout_exec };
static int aout_loadimage(int fd, vm_offset_t loadaddr, struct exec *ehdr);
/*
* Attempt to load the file (file) as an a.out module. It will be stored at
* (dest), and a pointer to a module structure describing the loaded object
* will be saved in (result).
*/
static int
aout_loadmodule(char *filename, vm_offset_t dest, struct loaded_module **result)
{
struct aout_kernel_module *mp;
struct exec ehdr;
int fd;
vm_offset_t addr;
int err;
u_int pad;
/*
* Open the image, read and validate the a.out header
*
* XXX what do kld modules look like? We only handle kernels here.
*/
if (filename == NULL) /* can't handle nameless */
return(EFTYPE);
if ((fd = open(filename, O_RDONLY)) == -1)
return(errno);
if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
return(EFTYPE); /* could be EIO, but may be small file */
if (N_BADMAG(ehdr))
return(EFTYPE);
/*
* Ok, we think this is for us.
*/
mp = malloc(sizeof(struct aout_kernel_module));
mp->m.m_name = strdup(filename); /* XXX should we prune the name? */
mp->m.m_type = "a.out kernel"; /* XXX only if that's what we really are */
mp->m.m_args = NULL; /* XXX should we put the bootstrap args here and parse later? */
mp->m.m_flags = MF_AOUT; /* we're an a.out kernel */
mp->m_entry = (vm_offset_t)(ehdr.a_entry & 0xffffff);
if (dest == 0)
dest = (vm_offset_t)(ehdr.a_entry & 0x100000);
if (mod_findmodule(NULL, mp->m.m_type) != NULL) {
printf("aout_loadmodule: kernel already loaded\n");
err = EPERM;
goto out;
}
printf("%s at 0x%x\n", filename, dest);
mp->m.m_addr = addr = dest;
mp->m.m_size = aout_loadimage(fd, addr, &ehdr);
printf("\n");
if (mp->m.m_size == 0)
goto ioerr;
/* XXX and if these parts don't exist? */
mp->m_bi.bi_symtab = mp->m.m_addr + ehdr.a_text + ehdr.a_data + ehdr.a_bss;
mp->m_bi.bi_esymtab = mp->m_bi.bi_symtab + sizeof(ehdr.a_syms) + ehdr.a_syms;
/* Load OK, return module pointer */
*result = (struct loaded_module *)mp;
return(0);
ioerr:
err = EIO;
out:
close(fd);
free(mp);
return(err);
}
/*
* With the file (fd) open on the image, and (ehdr) containing
* the exec header, load the image at (addr)
*
* Fixup the a_bss field in (ehdr) to reflect the padding added to
* align the symbol table.
*/
static int
aout_loadimage(int fd, vm_offset_t loadaddr, struct exec *ehdr)
{
u_int pad;
vm_offset_t addr;
int ss;
addr = loadaddr;
lseek(fd, N_TXTOFF(*ehdr), SEEK_SET);
/* text segment */
printf("text=0x%x ", ehdr->a_text);
if (pread(fd, addr, ehdr->a_text) != ehdr->a_text)
return(0);
addr += ehdr->a_text;
/* data segment */
printf("data=0x%x ", ehdr->a_data);
if (pread(fd, addr, ehdr->a_data) != ehdr->a_data)
return(0);
addr += ehdr->a_data;
/* skip the BSS */
printf("bss=0x%x ", ehdr->a_bss);
addr += ehdr->a_bss;
/* pad to a page boundary */
pad = (u_int)addr & PAGE_MASK;
if (pad != 0) {
pad = PAGE_SIZE - pad;
addr += pad;
ehdr->a_bss += pad;
}
/* XXX bi_symtab = addr */
/* symbol table size */
vpbcopy(&ehdr->a_syms, addr, sizeof(ehdr->a_syms));
addr += sizeof(ehdr->a_syms);
/* symbol table */
printf("symbols=[0x%x+0x%x+0x%x", pad, sizeof(ehdr->a_syms), ehdr->a_syms);
if (pread(fd, addr, ehdr->a_syms) != ehdr->a_syms)
return(0);
addr += ehdr->a_syms;
/* string table */
read(fd, &ss, sizeof(ss));
vpbcopy(&ss, addr, sizeof(ss));
addr += sizeof(ss);
ss -= sizeof(ss);
printf("+0x%x+0x%x]", sizeof(ss), ss);
if (pread(fd, addr, ss) != ss)
return(0);
/* XXX bi_esymtab = addr */
addr += ss;
return(addr - loadaddr);
}
/*
* There is an a.out kernel and one or more a.out modules loaded.
* We wish to start executing the kernel image, so make such
* preparations as are required, and do so.
*/
static int
aout_exec(struct loaded_module *amp)
{
struct aout_kernel_module *mp = (struct aout_kernel_module *)amp;
struct loaded_module *xp;
struct i386_devdesc *currdev;
u_int32_t argv[6]; /* kernel arguments */
int major, bootdevnr;
vm_offset_t addr;
u_int pad;
if ((amp->m_flags & MF_FORMATMASK) != MF_AOUT)
return(EFTYPE);
/* Boot from whatever the current device is */
i386_getdev((void **)(&currdev), NULL, NULL);
switch(currdev->d_type) {
case DEVT_DISK:
major = 0; /* XXX in the short term, have to work out a major number here for old kernels */
bootdevnr = MAKEBOOTDEV(major,
currdev->d_kind.biosdisk.slice >> 4,
currdev->d_kind.biosdisk.slice & 0xf,
currdev->d_kind.biosdisk.unit,
currdev->d_kind.biosdisk.partition);
break;
default:
printf("aout_loadmodule: WARNING - don't know how to boot from device type %d\n", currdev->d_type);
}
free(currdev);
/* Device data is kept in the kernel argv array */
argv[1] = bootdevnr;
argv[0] = bi_getboothowto(amp->m_args);
/* argv[2] = vtophys(bootinfo); /* old cyl offset (do we care about this?) */
argv[3] = 0;
argv[4] = 0;
argv[5] = (u_int32_t)vtophys(&(mp->m_bi));
/* legacy bootinfo structure */
mp->m_bi.bi_version = BOOTINFO_VERSION;
mp->m_bi.bi_memsizes_valid = 1;
/* XXX bi_vesa */
mp->m_bi.bi_basemem = getbasemem();
mp->m_bi.bi_extmem = getextmem();
/* find the last module in the chain */
for (xp = amp; xp->m_next != NULL; xp = xp->m_next)
;
addr = xp->m_addr + xp->m_size;
/* pad to a page boundary */
pad = (u_int)addr & PAGE_MASK;
if (pad != 0) {
pad = PAGE_SIZE - pad;
addr += pad;
}
/* copy our environment XXX save addr here as env pointer */
addr = bi_copyenv(addr);
/* pad to a page boundary */
pad = (u_int)addr & PAGE_MASK;
if (pad != 0) {
pad = PAGE_SIZE - pad;
addr += pad;
}
/* copy module list and metadata */
bi_copymodules(addr);
#ifdef DEBUG
{
int i;
for (i = 0; i < 6; i++)
printf("argv[%d]=%lx\n", i, argv[i]);
}
printf("Start @ 0x%lx ...\n", mp->m_entry);
#endif
startprog(mp->m_entry, 6, argv, (vm_offset_t)0x90000);
panic("exec returned");
}