1/*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: stable/11/stand/userboot/userboot/elf32_freebsd.c 261504 2014-02-05 04:39:03Z jhb $"); 29 30#include <sys/param.h> 31#include <sys/exec.h> 32#include <sys/linker.h> 33#include <string.h> 34#define _MACHINE_ELF_WANT_32BIT 35#include <i386/include/bootinfo.h> 36#include <i386/include/elf.h> 37#include <stand.h> 38 39#include "bootstrap.h" 40#include "libuserboot.h" 41 42static int elf32_exec(struct preloaded_file *amp); 43static int elf32_obj_exec(struct preloaded_file *amp); 44 45struct file_format i386_elf = { elf32_loadfile, elf32_exec }; 46struct file_format i386_elf_obj = { elf32_obj_loadfile, elf32_obj_exec }; 47 48#define GUEST_STACK 0x1000 /* Initial stack base */ 49#define GUEST_GDT 0x3000 /* Address of initial GDT */ 50 51/* 52 * There is an ELF kernel and one or more ELF modules loaded. 53 * We wish to start executing the kernel image, so make such 54 * preparations as are required, and do so. 55 */ 56static int 57elf32_exec(struct preloaded_file *fp) 58{ 59 struct file_metadata *md; 60 Elf_Ehdr *ehdr; 61 vm_offset_t entry, bootinfop, modulep, kernend; 62 int boothowto, err, bootdev; 63 uint32_t stack[1024], *sp; 64 65 66 if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL) 67 return(EFTYPE); 68 ehdr = (Elf_Ehdr *)&(md->md_data); 69 70 err = bi_load32(fp->f_args, &boothowto, &bootdev, &bootinfop, &modulep, &kernend); 71 if (err != 0) 72 return(err); 73 entry = ehdr->e_entry & 0xffffff; 74 75#ifdef DEBUG 76 printf("Start @ 0x%lx ...\n", entry); 77#endif 78 79 dev_cleanup(); 80 81 /* 82 * Build a scratch stack at physical 0x1000 83 */ 84 memset(stack, 0, sizeof(stack)); 85 sp = (uint32_t *)((char *)stack + sizeof(stack)); 86 *--sp = kernend; 87 *--sp = modulep; 88 *--sp = bootinfop; 89 *--sp = 0; 90 *--sp = 0; 91 *--sp = 0; 92 *--sp = bootdev; 93 *--sp = boothowto; 94 95 /* 96 * Fake return address to mimic "new" boot blocks. For more 97 * details see recover_bootinfo in locore.S. 98 */ 99 *--sp = 0xbeefface; 100 CALLBACK(copyin, stack, GUEST_STACK, sizeof(stack)); 101 CALLBACK(setreg, 4, (char *)sp - (char *)stack + GUEST_STACK); 102 103 CALLBACK(setgdt, GUEST_GDT, 8 * 4 - 1); 104 105 CALLBACK(exec, entry); 106 107 panic("exec returned"); 108} 109 110static int 111elf32_obj_exec(struct preloaded_file *fp) 112{ 113 return (EFTYPE); 114} 115