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/param.h> 28 #include <sys/exec.h> 29 #include <sys/linker.h> 30 #include <string.h> 31 #define _MACHINE_ELF_WANT_32BIT 32 #include <i386/include/bootinfo.h> 33 #include <i386/include/elf.h> 34 #include <stand.h> 35 36 #include "bootstrap.h" 37 #include "libuserboot.h" 38 39 static int elf32_exec(struct preloaded_file *amp); 40 static int elf32_obj_exec(struct preloaded_file *amp); 41 42 struct file_format i386_elf = { elf32_loadfile, elf32_exec }; 43 struct file_format i386_elf_obj = { elf32_obj_loadfile, elf32_obj_exec }; 44 45 #define GUEST_STACK 0x1000 /* Initial stack base */ 46 #define GUEST_GDT 0x3000 /* Address of initial GDT */ 47 48 /* 49 * There is an ELF kernel and one or more ELF modules loaded. 50 * We wish to start executing the kernel image, so make such 51 * preparations as are required, and do so. 52 */ 53 static int 54 elf32_exec(struct preloaded_file *fp) 55 { 56 struct file_metadata *md; 57 Elf_Ehdr *ehdr; 58 vm_offset_t entry, bootinfop, modulep, kernend; 59 int boothowto, err, bootdev; 60 uint32_t stack[1024], *sp; 61 62 63 if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL) 64 return(EFTYPE); 65 ehdr = (Elf_Ehdr *)&(md->md_data); 66 67 err = bi_load32(fp->f_args, &boothowto, &bootdev, &bootinfop, &modulep, &kernend); 68 if (err != 0) 69 return(err); 70 entry = ehdr->e_entry & 0xffffff; 71 72 #ifdef DEBUG 73 printf("Start @ 0x%lx ...\n", entry); 74 #endif 75 76 dev_cleanup(); 77 78 /* 79 * Build a scratch stack at physical 0x1000 80 */ 81 memset(stack, 0, sizeof(stack)); 82 sp = (uint32_t *)((char *)stack + sizeof(stack)); 83 *--sp = kernend; 84 *--sp = modulep; 85 *--sp = bootinfop; 86 *--sp = 0; 87 *--sp = 0; 88 *--sp = 0; 89 *--sp = bootdev; 90 *--sp = boothowto; 91 92 /* 93 * Fake return address to mimic "new" boot blocks. For more 94 * details see recover_bootinfo in locore.S. 95 */ 96 *--sp = 0xbeefface; 97 CALLBACK(copyin, stack, GUEST_STACK, sizeof(stack)); 98 CALLBACK(setreg, 4, (char *)sp - (char *)stack + GUEST_STACK); 99 100 CALLBACK(setgdt, GUEST_GDT, 8 * 4 - 1); 101 102 CALLBACK(exec, entry); 103 104 panic("exec returned"); 105 } 106 107 static int 108 elf32_obj_exec(struct preloaded_file *fp) 109 { 110 return (EFTYPE); 111 } 112