diff options
Diffstat (limited to 'stand/userboot/userboot/elf64_freebsd.c')
| -rw-r--r-- | stand/userboot/userboot/elf64_freebsd.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/stand/userboot/userboot/elf64_freebsd.c b/stand/userboot/userboot/elf64_freebsd.c new file mode 100644 index 000000000000..19d369d6d548 --- /dev/null +++ b/stand/userboot/userboot/elf64_freebsd.c @@ -0,0 +1,172 @@ +/*- + * 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#define __ELF_WORD_SIZE 64 +#include <sys/param.h> +#include <sys/exec.h> +#include <sys/linker.h> +#include <string.h> +#include <i386/include/bootinfo.h> +#include <machine/elf.h> +#include <stand.h> + +#include "bootstrap.h" +#include "libuserboot.h" + +static int elf64_exec(struct preloaded_file *amp); +static int elf64_obj_exec(struct preloaded_file *amp); + +struct file_format amd64_elf = { elf64_loadfile, elf64_exec }; +struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec }; + +#define MSR_EFER 0xc0000080 +#define EFER_LME 0x00000100 +#define EFER_LMA 0x00000400 /* Long mode active (R) */ +#define CR4_PAE 0x00000020 +#define CR4_VMXE (1UL << 13) +#define CR4_PSE 0x00000010 +#define CR0_PG 0x80000000 +#define CR0_PE 0x00000001 /* Protected mode Enable */ +#define CR0_NE 0x00000020 /* Numeric Error enable (EX16 vs IRQ13) */ + +#define PG_V 0x001 +#define PG_RW 0x002 +#define PG_U 0x004 +#define PG_PS 0x080 + +typedef u_int64_t p4_entry_t; +typedef u_int64_t p3_entry_t; +typedef u_int64_t p2_entry_t; + +#define GUEST_NULL_SEL 0 +#define GUEST_CODE_SEL 1 +#define GUEST_DATA_SEL 2 +#define GUEST_GDTR_LIMIT (3 * 8 - 1) + +static void +setup_freebsd_gdt(uint64_t *gdtr) +{ + gdtr[GUEST_NULL_SEL] = 0; + gdtr[GUEST_CODE_SEL] = 0x0020980000000000; + gdtr[GUEST_DATA_SEL] = 0x0000900000000000; +} + +/* + * There is an ELF kernel and one or more ELF modules loaded. + * We wish to start executing the kernel image, so make such + * preparations as are required, and do so. + */ +static int +elf64_exec(struct preloaded_file *fp) +{ + struct file_metadata *md; + Elf_Ehdr *ehdr; + vm_offset_t modulep, kernend; + int err; + int i; + uint32_t stack[1024]; + p4_entry_t PT4[512]; + p3_entry_t PT3[512]; + p2_entry_t PT2[512]; + uint64_t gdtr[3]; + + if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL) + return(EFTYPE); + ehdr = (Elf_Ehdr *)&(md->md_data); + + err = bi_load64(fp->f_args, &modulep, &kernend); + if (err != 0) + return(err); + + bzero(PT4, PAGE_SIZE); + bzero(PT3, PAGE_SIZE); + bzero(PT2, PAGE_SIZE); + + /* + * Build a scratch stack at physical 0x1000, page tables: + * PT4 at 0x2000, + * PT3 at 0x3000, + * PT2 at 0x4000, + * gdtr at 0x5000, + */ + + /* + * This is kinda brutal, but every single 1GB VM memory segment + * points to the same first 1GB of physical memory. But it is + * more than adequate. + */ + for (i = 0; i < 512; i++) { + /* Each slot of the level 4 pages points to the same level 3 page */ + PT4[i] = (p4_entry_t) 0x3000; + PT4[i] |= PG_V | PG_RW | PG_U; + + /* Each slot of the level 3 pages points to the same level 2 page */ + PT3[i] = (p3_entry_t) 0x4000; + PT3[i] |= PG_V | PG_RW | PG_U; + + /* The level 2 page slots are mapped with 2MB pages for 1GB. */ + PT2[i] = i * (2 * 1024 * 1024); + PT2[i] |= PG_V | PG_RW | PG_PS | PG_U; + } + +#ifdef DEBUG + printf("Start @ %#llx ...\n", ehdr->e_entry); +#endif + + dev_cleanup(); + + stack[0] = 0; /* return address */ + stack[1] = modulep; + stack[2] = kernend; + CALLBACK(copyin, stack, 0x1000, sizeof(stack)); + CALLBACK(copyin, PT4, 0x2000, sizeof(PT4)); + CALLBACK(copyin, PT3, 0x3000, sizeof(PT3)); + CALLBACK(copyin, PT2, 0x4000, sizeof(PT2)); + CALLBACK(setreg, 4, 0x1000); + + CALLBACK(setmsr, MSR_EFER, EFER_LMA | EFER_LME); + CALLBACK(setcr, 4, CR4_PAE | CR4_VMXE); + CALLBACK(setcr, 3, 0x2000); + CALLBACK(setcr, 0, CR0_PG | CR0_PE | CR0_NE); + + setup_freebsd_gdt(gdtr); + CALLBACK(copyin, gdtr, 0x5000, sizeof(gdtr)); + CALLBACK(setgdt, 0x5000, sizeof(gdtr)); + + CALLBACK(exec, ehdr->e_entry); + + panic("exec returned"); +} + +static int +elf64_obj_exec(struct preloaded_file *fp) +{ + + return (EFTYPE); +} |