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minimal-linux-script/syslinux-6.03/memdisk/setup.c
aimran96 ad93368a73 add build files
2023-11-16 23:19:36 -05:00

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/* ----------------------------------------------------------------------- *
*
* Copyright 2001-2009 H. Peter Anvin - All Rights Reserved
* Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
* Portions copyright 2009-2010 Shao Miller
* [El Torito code, mBFT, "safe hook"]
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
#include <stdint.h>
#include <minmax.h>
#include <suffix_number.h>
#include "bda.h"
#include "dskprobe.h"
#include "e820.h"
#include "conio.h"
#include "version.h"
#include "memdisk.h"
#include <version.h>
const char memdisk_version[] = "MEMDISK " VERSION_STR " " DATE;
const char copyright[] =
"Copyright " FIRSTYEAR "-" YEAR_STR " H. Peter Anvin et al";
extern const char _binary_memdisk_chs_512_bin_start[];
extern const char _binary_memdisk_chs_512_bin_end[];
extern const char _binary_memdisk_chs_512_bin_size[];
extern const char _binary_memdisk_edd_512_bin_start[];
extern const char _binary_memdisk_edd_512_bin_end[];
extern const char _binary_memdisk_edd_512_bin_size[];
extern const char _binary_memdisk_iso_512_bin_start[];
extern const char _binary_memdisk_iso_512_bin_end[];
extern const char _binary_memdisk_iso_512_bin_size[];
extern const char _binary_memdisk_iso_2048_bin_start[];
extern const char _binary_memdisk_iso_2048_bin_end[];
extern const char _binary_memdisk_iso_2048_bin_size[];
/* Pull in structures common to MEMDISK and MDISKCHK.COM */
#include "mstructs.h"
/* An EDD disk packet */
struct edd_dsk_pkt {
uint8_t size; /* Packet size */
uint8_t res1; /* Reserved */
uint16_t count; /* Count to transfer */
uint32_t buf; /* Buffer pointer */
uint64_t start; /* LBA to start from */
uint64_t buf64; /* 64-bit buf pointer */
} __attribute__ ((packed));
/* Change to 1 for El Torito debugging */
#define DBG_ELTORITO 0
#if DBG_ELTORITO
extern void eltorito_dump(uint32_t);
#endif
/*
* Routine to seek for a command-line item and return a pointer
* to the data portion, if present
*/
/* Magic return values */
#define CMD_NOTFOUND ((char *)-1) /* Not found */
#define CMD_BOOL ((char *)-2) /* Found boolean option */
#define CMD_HASDATA(X) ((int)(X) >= 0)
static const char *getcmditem(const char *what)
{
const char *p;
const char *wp = what;
int match = 0;
for (p = shdr->cmdline; *p; p++) {
switch (match) {
case 0: /* Ground state */
if (*p == ' ')
break;
wp = what;
match = 1;
/* Fall through */
case 1: /* Matching */
if (*wp == '\0') {
if (*p == '=')
return p + 1;
else if (*p == ' ')
return CMD_BOOL;
else {
match = 2;
break;
}
}
if (*p != *wp++)
match = 2;
break;
case 2: /* Mismatch, skip rest of option */
if (*p == ' ')
match = 0; /* Next option */
break;
}
}
/* Check for matching string at end of line */
if (match == 1 && *wp == '\0')
return CMD_BOOL;
return CMD_NOTFOUND;
}
/*
* Check to see if this is a gzip image
*/
#define UNZIP_ALIGN 512
extern const char _end[]; /* Symbol signalling end of data */
void unzip_if_needed(uint32_t * where_p, uint32_t * size_p)
{
uint32_t where = *where_p;
uint32_t size = *size_p;
uint32_t zbytes;
uint32_t startrange, endrange;
uint32_t gzdatasize, gzwhere;
uint32_t orig_crc, offset;
uint32_t target = 0;
int i, okmem;
/* Is it a gzip image? */
if (check_zip((void *)where, size, &zbytes, &gzdatasize,
&orig_crc, &offset) == 0) {
if (offset + zbytes > size) {
/*
* Assertion failure; check_zip is supposed to guarantee this
* never happens.
*/
die("internal error: check_zip returned nonsense\n");
}
/*
* Find a good place to put it: search memory ranges in descending
* order until we find one that is legal and fits
*/
okmem = 0;
for (i = nranges - 1; i >= 0; i--) {
/*
* We can't use > 4G memory (32 bits only.) Truncate to 2^32-1
* so we don't have to deal with funny wraparound issues.
*/
/* Must be memory */
if (ranges[i].type != 1)
continue;
/* Range start */
if (ranges[i].start >= 0xFFFFFFFF)
continue;
startrange = (uint32_t) ranges[i].start;
/* Range end (0 for end means 2^64) */
endrange = ((ranges[i + 1].start >= 0xFFFFFFFF ||
ranges[i + 1].start == 0)
? 0xFFFFFFFF : (uint32_t) ranges[i + 1].start);
/* Make sure we don't overwrite ourselves */
if (startrange < (uint32_t) _end)
startrange = (uint32_t) _end;
/* Allow for alignment */
startrange =
(ranges[i].start + (UNZIP_ALIGN - 1)) & ~(UNZIP_ALIGN - 1);
/* In case we just killed the whole range... */
if (startrange >= endrange)
continue;
/*
* Must be large enough... don't rely on gzwhere for this
* (wraparound)
*/
if (endrange - startrange < gzdatasize)
continue;
/*
* This is where the gz image would be put if we put it in this
* range...
*/
gzwhere = (endrange - gzdatasize) & ~(UNZIP_ALIGN - 1);
/* Cast to uint64_t just in case we're flush with the top byte */
if ((uint64_t) where + size >= gzwhere && where < endrange) {
/*
* Need to move source data to avoid compressed/uncompressed
* overlap
*/
uint32_t newwhere;
if (gzwhere - startrange < size)
continue; /* Can't fit both old and new */
newwhere = (gzwhere - size) & ~(UNZIP_ALIGN - 1);
printf("Moving compressed data from 0x%08x to 0x%08x\n",
where, newwhere);
memmove((void *)newwhere, (void *)where, size);
where = newwhere;
}
target = gzwhere;
okmem = 1;
break;
}
if (!okmem)
die("Not enough memory to decompress image (need 0x%08x bytes)\n",
gzdatasize);
printf("gzip image: decompressed addr 0x%08x, len 0x%08x: ",
target, gzdatasize);
*size_p = gzdatasize;
*where_p = (uint32_t) unzip((void *)(where + offset), zbytes,
gzdatasize, orig_crc, (void *)target);
}
}
/*
* Figure out the "geometry" of the disk in question
*/
struct geometry {
uint32_t sectors; /* Sector count */
uint32_t c, h, s; /* C/H/S geometry */
uint32_t offset; /* Byte offset for disk */
uint32_t boot_lba; /* LBA of bootstrap code */
uint8_t type; /* Type byte for INT 13h AH=08h */
uint8_t driveno; /* Drive no */
uint8_t sector_shift; /* Sector size as a power of 2 */
const char *hsrc, *ssrc; /* Origins of H and S geometries */
};
/* Format of a DOS partition table entry */
struct ptab_entry {
uint8_t active;
uint8_t start_h, start_s, start_c;
uint8_t type;
uint8_t end_h, end_s, end_c;
uint32_t start;
uint32_t size;
} __attribute__ ((packed));
/* Format of a FAT filesystem superblock */
struct fat_extra {
uint8_t bs_drvnum;
uint8_t bs_resv1;
uint8_t bs_bootsig;
uint32_t bs_volid;
char bs_vollab[11];
char bs_filsystype[8];
} __attribute__ ((packed));
struct fat_super {
uint8_t bs_jmpboot[3];
char bs_oemname[8];
uint16_t bpb_bytspersec;
uint8_t bpb_secperclus;
uint16_t bpb_rsvdseccnt;
uint8_t bpb_numfats;
uint16_t bpb_rootentcnt;
uint16_t bpb_totsec16;
uint8_t bpb_media;
uint16_t bpb_fatsz16;
uint16_t bpb_secpertrk;
uint16_t bpb_numheads;
uint32_t bpb_hiddsec;
uint32_t bpb_totsec32;
union {
struct {
struct fat_extra extra;
} fat16;
struct {
uint32_t bpb_fatsz32;
uint16_t bpb_extflags;
uint16_t bpb_fsver;
uint32_t bpb_rootclus;
uint16_t bpb_fsinfo;
uint16_t bpb_bkbootsec;
char bpb_reserved[12];
/* Clever, eh? Same fields, different offset... */
struct fat_extra extra;
} fat32 __attribute__ ((packed));
} x;
} __attribute__ ((packed));
/* Format of a DOSEMU header */
struct dosemu_header {
uint8_t magic[7]; /* DOSEMU\0 */
uint32_t h;
uint32_t s;
uint32_t c;
uint32_t offset;
uint8_t pad[105];
} __attribute__ ((packed));
#define FOUR(a,b,c,d) (((a) << 24)|((b) << 16)|((c) << 8)|(d))
static const struct geometry *get_disk_image_geometry(uint32_t where,
uint32_t size)
{
static struct geometry hd_geometry;
struct dosemu_header dosemu;
unsigned int sectors, xsectors, v;
unsigned int offset;
int i;
const char *p;
printf("command line: %s\n", shdr->cmdline);
hd_geometry.sector_shift = 9; /* Assume floppy/HDD at first */
offset = 0;
if (CMD_HASDATA(p = getcmditem("offset")) && (v = atou(p)))
offset = v;
sectors = xsectors = (size - offset) >> hd_geometry.sector_shift;
hd_geometry.hsrc = "guess";
hd_geometry.ssrc = "guess";
hd_geometry.sectors = sectors;
hd_geometry.offset = offset;
if ((p = getcmditem("iso")) != CMD_NOTFOUND) {
#if DBG_ELTORITO
eltorito_dump(where);
#endif
struct edd4_bvd *bvd = (struct edd4_bvd *)(where + 17 * 2048);
/* Tiny sanity check */
if ((bvd->boot_rec_ind != 0) || (bvd->ver != 1))
printf("El Torito BVD sanity check failed.\n");
struct edd4_bootcat *boot_cat =
(struct edd4_bootcat *)(where + bvd->boot_cat * 2048);
/* Another tiny sanity check */
if ((boot_cat->validation_entry.platform_id != 0) ||
(boot_cat->validation_entry.key55 != 0x55) ||
(boot_cat->validation_entry.keyAA != 0xAA))
printf("El Torito boot catalog sanity check failed.\n");
/* If we have an emulation mode, set the offset to the image */
if (boot_cat->initial_entry.media_type)
hd_geometry.offset += boot_cat->initial_entry.load_block * 2048;
else
/* We're a no-emulation mode, so we will boot to an offset */
hd_geometry.boot_lba = boot_cat->initial_entry.load_block * 4;
if (boot_cat->initial_entry.media_type < 4) {
/* We're a floppy emulation mode or our params will be
* overwritten by the no emulation mode case
*/
hd_geometry.driveno = 0x00;
hd_geometry.c = 80;
hd_geometry.h = 2;
}
switch (boot_cat->initial_entry.media_type) {
case 0: /* No emulation */
hd_geometry.driveno = 0xE0;
hd_geometry.type = 10; /* ATAPI removable media device */
hd_geometry.c = 65535;
hd_geometry.h = 255;
hd_geometry.s = 15;
/* 2048-byte sectors, so adjust the size and count */
hd_geometry.sector_shift = 11;
break;
case 1: /* 1.2 MB floppy */
hd_geometry.s = 15;
hd_geometry.type = 2;
sectors = 2400;
break;
case 2: /* 1.44 MB floppy */
hd_geometry.s = 18;
hd_geometry.type = 4;
sectors = 2880;
break;
case 3: /* 2.88 MB floppy */
hd_geometry.s = 36;
hd_geometry.type = 6;
sectors = 5760;
break;
case 4:
hd_geometry.driveno = 0x80;
hd_geometry.type = 0;
break;
}
sectors = (size - hd_geometry.offset) >> hd_geometry.sector_shift;
/* For HDD emulation, we figure out the geometry later. Otherwise: */
if (hd_geometry.s) {
hd_geometry.hsrc = hd_geometry.ssrc = "El Torito";
}
hd_geometry.sectors = sectors;
}
/* Do we have a DOSEMU header? */
memcpy(&dosemu, (char *)where + hd_geometry.offset, sizeof dosemu);
if (!memcmp("DOSEMU", dosemu.magic, 7)) {
/* Always a hard disk unless overruled by command-line options */
hd_geometry.driveno = 0x80;
hd_geometry.type = 0;
hd_geometry.c = dosemu.c;
hd_geometry.h = dosemu.h;
hd_geometry.s = dosemu.s;
hd_geometry.offset += dosemu.offset;
sectors = (size - hd_geometry.offset) >> hd_geometry.sector_shift;
hd_geometry.hsrc = hd_geometry.ssrc = "DOSEMU";
}
if (CMD_HASDATA(p = getcmditem("c")) && (v = atou(p)))
hd_geometry.c = v;
if (CMD_HASDATA(p = getcmditem("h")) && (v = atou(p))) {
hd_geometry.h = v;
hd_geometry.hsrc = "cmd";
}
if (CMD_HASDATA(p = getcmditem("s")) && (v = atou(p))) {
hd_geometry.s = v;
hd_geometry.ssrc = "cmd";
}
if (!hd_geometry.h || !hd_geometry.s) {
int h, s, max_h, max_s;
max_h = hd_geometry.h;
max_s = hd_geometry.s;
if (!(max_h | max_s)) {
/* Look for a FAT superblock and if we find something that looks
enough like one, use geometry from that. This takes care of
megafloppy images and unpartitioned hard disks. */
const struct fat_extra *extra = NULL;
const struct fat_super *fs = (const struct fat_super *)
((char *)where + hd_geometry.offset);
if ((fs->bpb_media == 0xf0 || fs->bpb_media >= 0xf8) &&
(fs->bs_jmpboot[0] == 0xe9 || fs->bs_jmpboot[0] == 0xeb) &&
fs->bpb_bytspersec == 512 &&
fs->bpb_numheads >= 1 && fs->bpb_numheads <= 256 &&
fs->bpb_secpertrk >= 1 && fs->bpb_secpertrk <= 63) {
extra =
fs->bpb_fatsz16 ? &fs->x.fat16.extra : &fs->x.fat32.extra;
if (!
(extra->bs_bootsig == 0x29 && extra->bs_filsystype[0] == 'F'
&& extra->bs_filsystype[1] == 'A'
&& extra->bs_filsystype[2] == 'T'))
extra = NULL;
}
if (extra) {
hd_geometry.driveno = extra->bs_drvnum & 0x80;
max_h = fs->bpb_numheads;
max_s = fs->bpb_secpertrk;
hd_geometry.hsrc = hd_geometry.ssrc = "FAT";
}
}
if (!(max_h | max_s)) {
/* No FAT filesystem found to steal geometry from... */
if ((sectors < 4096 * 2) && (hd_geometry.sector_shift == 9)) {
int ok = 0;
unsigned int xsectors = sectors;
hd_geometry.driveno = 0; /* Assume floppy */
while (!ok) {
/* Assume it's a floppy drive, guess a geometry */
unsigned int type, track;
int c, h, s = 0;
if (xsectors < 320 * 2) {
c = 40;
h = 1;
type = 1;
} else if (xsectors < 640 * 2) {
c = 40;
h = 2;
type = 1;
} else if (xsectors < 1200 * 2) {
c = 80;
h = 2;
type = 3;
} else if (xsectors < 1440 * 2) {
c = 80;
h = 2;
type = 2;
} else if (xsectors < 2880 * 2) {
c = 80;
h = 2;
type = 4;
} else {
c = 80;
h = 2;
type = 6;
}
track = c * h;
while (c < 256) {
s = xsectors / track;
if (s < 63 && (xsectors % track) == 0) {
ok = 1;
break;
}
c++;
track += h;
}
if (ok) {
max_h = h;
max_s = s;
hd_geometry.hsrc = hd_geometry.ssrc = "fd";
} else {
/* No valid floppy geometry, fake it by simulating broken
sectors at the end of the image... */
xsectors++;
}
hd_geometry.type = type;
}
} else {
/* Assume it is a hard disk image and scan for a partition table */
const struct ptab_entry *ptab = (const struct ptab_entry *)
((char *)where + hd_geometry.offset + (512 - 2 - 4 * 16));
/* Assume hard disk */
if (!hd_geometry.driveno)
hd_geometry.driveno = 0x80;
if (*(uint16_t *) ((char *)where + hd_geometry.offset + 512 - 2) == 0xaa55) {
for (i = 0; i < 4; i++) {
if (ptab[i].type && !(ptab[i].active & 0x7f)) {
s = (ptab[i].start_s & 0x3f);
h = ptab[i].start_h + 1;
if (max_h < h)
max_h = h;
if (max_s < s)
max_s = s;
s = (ptab[i].end_s & 0x3f);
h = ptab[i].end_h + 1;
if (max_h < h) {
max_h = h;
hd_geometry.hsrc = "MBR";
}
if (max_s < s) {
max_s = s;
hd_geometry.ssrc = "MBR";
}
}
}
}
hd_geometry.type = 0;
}
}
if (!max_h)
max_h = xsectors > 2097152 ? 255 : 64;
if (!max_s)
max_s = xsectors > 2097152 ? 63 : 32;
hd_geometry.h = max_h;
hd_geometry.s = max_s;
}
if (!hd_geometry.c)
hd_geometry.c = xsectors / (hd_geometry.h * hd_geometry.s);
if ((p = getcmditem("floppy")) != CMD_NOTFOUND) {
hd_geometry.driveno = CMD_HASDATA(p) ? atou(p) & 0x7f : 0;
} else if ((p = getcmditem("harddisk")) != CMD_NOTFOUND) {
hd_geometry.driveno = CMD_HASDATA(p) ? atou(p) | 0x80 : 0x80;
}
if (hd_geometry.driveno & 0x80) {
hd_geometry.type = 0; /* Type = hard disk */
} else {
if (hd_geometry.type == 0)
hd_geometry.type = 0x10; /* ATAPI floppy, e.g. LS-120 */
}
if ((size - hd_geometry.offset) & 0x1ff) {
puts("MEMDISK: Image has fractional end sector\n");
}
if (sectors % (hd_geometry.h * hd_geometry.s)) {
puts("MEMDISK: Image seems to have fractional end cylinder\n");
}
if ((hd_geometry.c * hd_geometry.h * hd_geometry.s) > sectors) {
puts("MEMDISK: Image appears to be truncated\n");
}
return &hd_geometry;
}
/*
* Find a $PnP installation check structure; return (ES << 16) + DI value
*/
static uint32_t pnp_install_check(void)
{
uint32_t *seg;
unsigned char *p, csum;
int i, len;
for (seg = (uint32_t *) 0xf0000; seg < (uint32_t *) 0x100000; seg += 4) {
if (*seg == ('$' + ('P' << 8) + ('n' << 16) + ('P' << 24))) {
p = (unsigned char *)seg;
len = p[5];
if (len < 0x21)
continue;
csum = 0;
for (i = len; i; i--)
csum += *p++;
if (csum != 0)
continue;
return (0xf000 << 16) + (uint16_t) (unsigned long)seg;
}
}
return 0;
}
/*
* Relocate the real-mode code to a new segment
*/
struct gdt_ptr {
uint16_t limit;
uint32_t base;
} __attribute__ ((packed));
static void set_seg_base(uint32_t gdt_base, int seg, uint32_t v)
{
*(uint16_t *) (gdt_base + seg + 2) = v;
*(uint8_t *) (gdt_base + seg + 4) = v >> 16;
*(uint8_t *) (gdt_base + seg + 7) = v >> 24;
}
static void relocate_rm_code(uint32_t newbase)
{
uint32_t gdt_base;
uint32_t oldbase = rm_args.rm_base;
uint32_t delta = newbase - oldbase;
cli();
memmove((void *)newbase, (void *)oldbase, rm_args.rm_size);
rm_args.rm_return += delta;
rm_args.rm_intcall += delta;
rm_args.rm_bounce += delta;
rm_args.rm_base += delta;
rm_args.rm_gdt += delta;
rm_args.rm_pmjmp += delta;
rm_args.rm_rmjmp += delta;
gdt_base = rm_args.rm_gdt;
*(uint32_t *) (gdt_base + 2) = gdt_base; /* GDT self-pointer */
/* Segments 0x10 and 0x18 are real-mode-based */
set_seg_base(gdt_base, 0x10, rm_args.rm_base);
set_seg_base(gdt_base, 0x18, rm_args.rm_base);
#if __SIZEOF_POINTER__ == 4
asm volatile ("lgdtl %0"::"m" (*(char *)gdt_base));
#elif __SIZEOF_POINTER__ == 8
asm volatile ("lgdt %0"::"m" (*(char *)gdt_base));
#else
#error "unsupported architecture"
#endif
*(uint32_t *) rm_args.rm_pmjmp += delta;
*(uint16_t *) rm_args.rm_rmjmp += delta >> 4;
rm_args.rm_handle_interrupt += delta;
sti();
}
static uint8_t checksum_buf(const void *buf, int count)
{
const uint8_t *p = buf;
uint8_t c = 0;
while (count--)
c += *p++;
return c;
}
static int stack_needed(void)
{
const unsigned int min_stack = 128; /* Minimum stack size */
const unsigned int def_stack = 512; /* Default stack size */
unsigned int v = 0;
const char *p;
if (CMD_HASDATA(p = getcmditem("stack")))
v = atou(p);
if (!v)
v = def_stack;
if (v < min_stack)
v = min_stack;
return v;
}
/*
* Set max memory by reservation
* Adds reservations to data in INT15h to prevent access to the top of RAM
* if there's any above the point specified.
*/
void setmaxmem(unsigned long long restop_ull)
{
uint32_t restop;
struct e820range *ep;
const int int15restype = 2;
/* insertrange() works on uint32_t */
restop = min(restop_ull, UINT32_MAX);
/* printf(" setmaxmem '%08x%08x' => %08x\n",
(unsigned int)(restop_ull>>32), (unsigned int)restop_ull, restop); */
for (ep = ranges; ep->type != -1U; ep++) {
if (ep->type == 1) { /* Only if available */
if (ep->start >= restop) {
/* printf(" %08x -> 2\n", ep->start); */
ep->type = int15restype;
} else if (ep[1].start > restop) {
/* printf(" +%08x =2; cut %08x\n", restop, ep->start); */
insertrange(restop, (ep[1].start - restop), int15restype);
}
}
}
parse_mem();
}
struct real_mode_args rm_args;
/*
* Actual setup routine
* Returns the drive number (which is then passed in %dl to the
* called routine.)
*/
void setup(const struct real_mode_args *rm_args_ptr)
{
unsigned int bin_size;
char *memdisk_hook;
struct memdisk_header *hptr;
struct patch_area *pptr;
struct mBFT *mbft;
uint16_t driverseg;
uint32_t driverptr, driveraddr;
uint16_t dosmem_k;
uint32_t stddosmem;
const struct geometry *geometry;
unsigned int total_size;
unsigned int cmdline_len, stack_len, e820_len;
const struct edd4_bvd *bvd;
const struct edd4_bootcat *boot_cat = 0;
com32sys_t regs;
uint32_t ramdisk_image, ramdisk_size;
uint32_t boot_base, rm_base;
int bios_drives;
int do_edd = 1; /* 0 = no, 1 = yes, default is yes */
int do_eltorito = 0; /* default is no */
int no_bpt; /* No valid BPT presented */
uint32_t boot_seg = 0; /* Meaning 0000:7C00 */
uint32_t boot_len = 512; /* One sector */
const char *p;
/* We need to copy the rm_args into their proper place */
memcpy(&rm_args, rm_args_ptr, sizeof rm_args);
sti(); /* ... then interrupts are safe */
/* Show signs of life */
printf("%s %s\n", memdisk_version, copyright);
if (!shdr->ramdisk_image || !shdr->ramdisk_size)
die("MEMDISK: No ramdisk image specified!\n");
ramdisk_image = shdr->ramdisk_image;
ramdisk_size = shdr->ramdisk_size;
e820map_init(); /* Initialize memory data structure */
get_mem(); /* Query BIOS for memory map */
parse_mem(); /* Parse memory map */
printf("Ramdisk at 0x%08x, length 0x%08x\n", ramdisk_image, ramdisk_size);
unzip_if_needed(&ramdisk_image, &ramdisk_size);
geometry = get_disk_image_geometry(ramdisk_image, ramdisk_size);
if (getcmditem("edd") != CMD_NOTFOUND ||
getcmditem("ebios") != CMD_NOTFOUND)
do_edd = 1;
else if (getcmditem("noedd") != CMD_NOTFOUND ||
getcmditem("noebios") != CMD_NOTFOUND ||
getcmditem("cbios") != CMD_NOTFOUND)
do_edd = 0;
else
do_edd = (geometry->driveno & 0x80) ? 1 : 0;
if (getcmditem("iso") != CMD_NOTFOUND) {
do_eltorito = 1;
do_edd = 1; /* Mandatory */
}
/* Choose the appropriate installable memdisk hook */
if (do_eltorito) {
if (geometry->sector_shift == 11) {
bin_size = (int)&_binary_memdisk_iso_2048_bin_size;
memdisk_hook = (char *)&_binary_memdisk_iso_2048_bin_start;
} else {
bin_size = (int)&_binary_memdisk_iso_512_bin_size;
memdisk_hook = (char *)&_binary_memdisk_iso_512_bin_start;
}
} else {
if (do_edd) {
bin_size = (int)&_binary_memdisk_edd_512_bin_size;
memdisk_hook = (char *)&_binary_memdisk_edd_512_bin_start;
} else {
bin_size = (int)&_binary_memdisk_chs_512_bin_size;
memdisk_hook = (char *)&_binary_memdisk_chs_512_bin_start;
}
}
/* Reserve the ramdisk memory */
insertrange(ramdisk_image, ramdisk_size, 2);
parse_mem(); /* Recompute variables */
/* Figure out where it needs to go */
hptr = (struct memdisk_header *)memdisk_hook;
pptr = (struct patch_area *)(memdisk_hook + hptr->patch_offs);
dosmem_k = rdz_16(BIOS_BASEMEM);
pptr->mdi.olddosmem = dosmem_k;
stddosmem = dosmem_k << 10;
/* If INT 15 E820 and INT 12 disagree, go with the most conservative */
if (stddosmem > dos_mem)
stddosmem = dos_mem;
pptr->driveno = geometry->driveno;
pptr->drivetype = geometry->type;
pptr->cylinders = geometry->c; /* Possible precision loss */
pptr->heads = geometry->h;
pptr->sectors = geometry->s;
pptr->mdi.disksize = geometry->sectors;
pptr->mdi.diskbuf = ramdisk_image + geometry->offset;
pptr->mdi.sector_shift = geometry->sector_shift;
pptr->statusptr = (geometry->driveno & 0x80) ? 0x474 : 0x441;
pptr->mdi.bootloaderid = shdr->type_of_loader;
pptr->configflags = CONFIG_SAFEINT; /* Default */
/* Set config flags */
if (getcmditem("ro") != CMD_NOTFOUND) {
pptr->configflags |= CONFIG_READONLY;
}
if (getcmditem("raw") != CMD_NOTFOUND) {
pptr->configflags &= ~CONFIG_MODEMASK;
pptr->configflags |= CONFIG_RAW;
}
if (getcmditem("bigraw") != CMD_NOTFOUND) {
pptr->configflags &= ~CONFIG_MODEMASK;
pptr->configflags |= CONFIG_BIGRAW | CONFIG_RAW;
}
if (getcmditem("int") != CMD_NOTFOUND) {
pptr->configflags &= ~CONFIG_MODEMASK;
/* pptr->configflags |= 0; */
}
if (getcmditem("safeint") != CMD_NOTFOUND) {
pptr->configflags &= ~CONFIG_MODEMASK;
pptr->configflags |= CONFIG_SAFEINT;
}
printf("Disk is %s%d, %u%s K, C/H/S = %u/%u/%u (%s/%s), EDD %s, %s\n",
(geometry->driveno & 0x80) ? "hd" : "fd",
geometry->driveno & 0x7f,
geometry->sectors >> 1,
(geometry->sectors & 1) ? ".5" : "",
geometry->c, geometry->h, geometry->s,
geometry->hsrc, geometry->ssrc,
do_edd ? "on" : "off",
pptr->configflags & CONFIG_READONLY ? "ro" : "rw");
puts("Using ");
switch (pptr->configflags & CONFIG_MODEMASK) {
case 0:
puts("standard INT 15h");
break;
case CONFIG_SAFEINT:
puts("safe INT 15h");
break;
case CONFIG_RAW:
puts("raw");
break;
case CONFIG_RAW | CONFIG_BIGRAW:
puts("big real mode raw");
break;
default:
printf("unknown %#x", pptr->configflags & CONFIG_MODEMASK);
break;
}
puts(" access to high memory\n");
/* Set up a drive parameter table */
if (geometry->driveno & 0x80) {
/* Hard disk */
pptr->dpt.hd.max_cyl = geometry->c - 1;
pptr->dpt.hd.max_head = geometry->h - 1;
pptr->dpt.hd.ctrl = (geometry->h > 8) ? 0x08 : 0;
} else {
/* Floppy - most of these fields are bogus and mimic
a 1.44 MB floppy drive */
pptr->dpt.fd.specify1 = 0xdf;
pptr->dpt.fd.specify2 = 0x02;
pptr->dpt.fd.delay = 0x25;
pptr->dpt.fd.sectors = geometry->s;
pptr->dpt.fd.bps = 0x02;
pptr->dpt.fd.isgap = 0x12;
pptr->dpt.fd.dlen = 0xff;
pptr->dpt.fd.fgap = 0x6c;
pptr->dpt.fd.ffill = 0xf6;
pptr->dpt.fd.settle = 0x0f;
pptr->dpt.fd.mstart = 0x05;
pptr->dpt.fd.maxtrack = geometry->c - 1;
pptr->dpt.fd.cmos = geometry->type > 5 ? 5 : geometry->type;
pptr->dpt.fd.old_fd_dpt = rdz_32(BIOS_INT1E);
}
/* Set up an EDD drive parameter table */
if (do_edd) {
pptr->edd_dpt.sectors = geometry->sectors;
/* The EDD spec has this as <= 15482880 sectors (1024x240x63);
this seems to make very little sense. Try for something saner. */
if (geometry->c <= 1024 && geometry->h <= 255 && geometry->s <= 63) {
pptr->edd_dpt.c = geometry->c;
pptr->edd_dpt.h = geometry->h;
pptr->edd_dpt.s = geometry->s;
/* EDD-4 states that invalid geometry should be returned
* for INT 0x13, AH=0x48 "EDD Get Disk Parameters" call on an
* El Torito ODD. Check for 2048-byte sector size
*/
if (geometry->sector_shift != 11)
pptr->edd_dpt.flags |= 0x0002; /* Geometry valid */
}
if (!(geometry->driveno & 0x80)) {
/* Floppy drive. Mark it as a removable device with
media change notification; media is present. */
pptr->edd_dpt.flags |= 0x0014;
}
pptr->edd_dpt.devpath[0] = pptr->mdi.diskbuf;
pptr->edd_dpt.chksum = -checksum_buf(&pptr->edd_dpt.dpikey, 73 - 30);
}
if (do_eltorito) {
bvd = (struct edd4_bvd *)(ramdisk_image + 17 * 2048);
boot_cat =
(struct edd4_bootcat *)(ramdisk_image + bvd->boot_cat * 2048);
pptr->cd_pkt.type = boot_cat->initial_entry.media_type; /* Cheat */
pptr->cd_pkt.driveno = geometry->driveno;
pptr->cd_pkt.start = boot_cat->initial_entry.load_block;
boot_seg = pptr->cd_pkt.load_seg = boot_cat->initial_entry.load_seg;
pptr->cd_pkt.sect_count = boot_cat->initial_entry.sect_count;
boot_len = pptr->cd_pkt.sect_count * 512;
pptr->cd_pkt.geom1 = (uint8_t)(pptr->cylinders) & 0xFF;
pptr->cd_pkt.geom2 =
(uint8_t)(pptr->sectors) | (uint8_t)((pptr->cylinders >> 2) & 0xC0);
pptr->cd_pkt.geom3 = (uint8_t)(pptr->heads);
}
if ((p = getcmditem("mem")) != CMD_NOTFOUND) {
setmaxmem(suffix_number(p));
}
/* The size is given by hptr->total_size plus the size of the E820
map -- 12 bytes per range; we may need as many as 2 additional
ranges (each insertrange() can worst-case turn 1 area into 3)
plus the terminating range, over what nranges currently show. */
total_size = hptr->total_size; /* Actual memdisk code */
e820_len = (nranges + 3) * sizeof(ranges[0]);
total_size += e820_len; /* E820 memory ranges */
cmdline_len = strlen(shdr->cmdline) + 1;
total_size += cmdline_len; /* Command line */
stack_len = stack_needed();
total_size += stack_len; /* Stack */
printf("Code %u, meminfo %u, cmdline %u, stack %u\n",
hptr->total_size, e820_len, cmdline_len, stack_len);
printf("Total size needed = %u bytes, allocating %uK\n",
total_size, (total_size + 0x3ff) >> 10);
if (total_size > dos_mem)
die("MEMDISK: Insufficient low memory\n");
driveraddr = stddosmem - total_size;
driveraddr &= ~0x3FF;
printf("Old dos memory at 0x%05x (map says 0x%05x), loading at 0x%05x\n",
stddosmem, dos_mem, driveraddr);
/* Reserve this range of memory */
wrz_16(BIOS_BASEMEM, driveraddr >> 10);
insertrange(driveraddr, dos_mem - driveraddr, 2);
parse_mem();
pptr->mem1mb = low_mem >> 10;
pptr->mem16mb = high_mem >> 16;
if (low_mem == (15 << 20)) {
/* lowmem maxed out */
uint32_t int1588mem = (high_mem >> 10) + (low_mem >> 10);
pptr->memint1588 = (int1588mem > 0xffff) ? 0xffff : int1588mem;
} else {
pptr->memint1588 = low_mem >> 10;
}
printf("1588: 0x%04x 15E801: 0x%04x 0x%04x\n",
pptr->memint1588, pptr->mem1mb, pptr->mem16mb);
driverseg = driveraddr >> 4;
driverptr = driverseg << 16;
/* Anything beyond the end is for the stack */
pptr->mystack = (uint16_t) (stddosmem - driveraddr);
pptr->mdi.oldint13.uint32 = rdz_32(BIOS_INT13);
pptr->mdi.oldint15.uint32 = rdz_32(BIOS_INT15);
/* Adjust the E820 table: if there are null ranges (type 0)
at the end, change them to type end of list (-1).
This is necessary for the driver to be able to report end
of list correctly. */
while (nranges && ranges[nranges - 1].type == 0) {
ranges[--nranges].type = -1;
}
if (getcmditem("nopassany") != CMD_NOTFOUND) {
printf("nopassany specified - we're the only drive of any kind\n");
bios_drives = 0;
pptr->drivecnt = 0;
no_bpt = 1;
pptr->mdi.oldint13.uint32 = driverptr + hptr->iret_offs;
wrz_8(BIOS_EQUIP, rdz_8(BIOS_EQUIP) & ~0xc1);
wrz_8(BIOS_HD_COUNT, 0);
} else if (getcmditem("nopass") != CMD_NOTFOUND) {
printf("nopass specified - we're the only drive\n");
bios_drives = 0;
pptr->drivecnt = 0;
no_bpt = 1;
} else {
/* Query drive parameters of this type */
memset(&regs, 0, sizeof regs);
regs.es = 0;
regs.eax.b[1] = 0x08;
regs.edx.b[0] = geometry->driveno & 0x80;
intcall(0x13, &regs, &regs);
/* Note: per suggestion from the Interrupt List, consider
INT 13 08 to have failed if the sector count in CL is zero. */
if ((regs.eflags.l & 1) || !(regs.ecx.b[0] & 0x3f)) {
printf("INT 13 08: Failure, assuming this is the only drive\n");
pptr->drivecnt = 0;
no_bpt = 1;
} else {
printf("INT 13 08: Success, count = %u, BPT = %04x:%04x\n",
regs.edx.b[0], regs.es, regs.edi.w[0]);
pptr->drivecnt = regs.edx.b[0];
no_bpt = !(regs.es | regs.edi.w[0]);
}
/* Compare what INT 13h returned with the appropriate equipment byte */
if (geometry->driveno & 0x80) {
bios_drives = rdz_8(BIOS_HD_COUNT);
} else {
uint8_t equip = rdz_8(BIOS_EQUIP);
if (equip & 1)
bios_drives = (equip >> 6) + 1;
else
bios_drives = 0;
}
if (pptr->drivecnt > bios_drives) {
printf("BIOS equipment byte says count = %d, go with that\n",
bios_drives);
pptr->drivecnt = bios_drives;
}
}
/* Add ourselves to the drive count */
pptr->drivecnt++;
/* Discontiguous drive space. There is no really good solution for this. */
if (pptr->drivecnt <= (geometry->driveno & 0x7f))
pptr->drivecnt = (geometry->driveno & 0x7f) + 1;
/* Probe for contiguous range of BIOS drives starting with driveno */
pptr->driveshiftlimit = probe_drive_range(geometry->driveno) + 1;
if ((pptr->driveshiftlimit & 0x80) != (geometry->driveno & 0x80))
printf("We lost the last drive in our class of drives.\n");
printf("Drive probing gives drive shift limit: 0x%02x\n",
pptr->driveshiftlimit);
/* Pointer to the command line */
pptr->mdi.cmdline.seg_off.offset = bin_size + (nranges + 1) * sizeof(ranges[0]);
pptr->mdi.cmdline.seg_off.segment = driverseg;
/* Copy driver followed by E820 table followed by command line */
{
unsigned char *dpp = (unsigned char *)(driverseg << 4);
/* Adjust these pointers to point to the installed image */
/* Careful about the order here... the image isn't copied yet! */
pptr = (struct patch_area *)(dpp + hptr->patch_offs);
hptr = (struct memdisk_header *)dpp;
/* Actually copy to low memory */
dpp = mempcpy(dpp, memdisk_hook, bin_size);
dpp = mempcpy(dpp, ranges, (nranges + 1) * sizeof(ranges[0]));
dpp = mempcpy(dpp, shdr->cmdline, cmdline_len);
}
/* Note the previous INT 13h hook in the "safe hook" structure */
hptr->safe_hook.old_hook.uint32 = pptr->mdi.oldint13.uint32;
/* Re-fill the "safe hook" mBFT field with the physical address */
mbft = (struct mBFT *)(((const char *)hptr) + hptr->safe_hook.mbft);
hptr->safe_hook.mbft = (size_t)mbft;
/* Update various BIOS magic data areas (gotta love this shit) */
if (geometry->driveno & 0x80) {
/* Update BIOS hard disk count */
uint8_t nhd = pptr->drivecnt;
if (nhd > 128)
nhd = 128;
if (!do_eltorito)
wrz_8(BIOS_HD_COUNT, nhd);
} else {
/* Update BIOS floppy disk count */
uint8_t equip = rdz_8(BIOS_EQUIP);
uint8_t nflop = pptr->drivecnt;
if (nflop > 4) /* Limit of equipment byte */
nflop = 4;
equip &= 0x3E;
if (nflop)
equip |= ((nflop - 1) << 6) | 0x01;
wrz_8(BIOS_EQUIP, equip);
/* Install DPT pointer if this was the only floppy */
if (getcmditem("dpt") != CMD_NOTFOUND ||
((nflop == 1 || no_bpt) && getcmditem("nodpt") == CMD_NOTFOUND)) {
/* Do install a replacement DPT into INT 1Eh */
pptr->mdi.dpt_ptr =
hptr->patch_offs + offsetof(struct patch_area, dpt);
}
}
/* Complete the mBFT */
mbft->acpi.signature[0] = 'm'; /* "mBFT" */
mbft->acpi.signature[1] = 'B';
mbft->acpi.signature[2] = 'F';
mbft->acpi.signature[3] = 'T';
mbft->safe_hook = (size_t)&hptr->safe_hook;
mbft->acpi.checksum = -checksum_buf(mbft, mbft->acpi.length);
/* Install the interrupt handlers */
printf("old: int13 = %08x int15 = %08x int1e = %08x\n",
rdz_32(BIOS_INT13), rdz_32(BIOS_INT15), rdz_32(BIOS_INT1E));
wrz_32(BIOS_INT13, driverptr + hptr->int13_offs);
wrz_32(BIOS_INT15, driverptr + hptr->int15_offs);
if (pptr->mdi.dpt_ptr)
wrz_32(BIOS_INT1E, driverptr + pptr->mdi.dpt_ptr);
printf("new: int13 = %08x int15 = %08x int1e = %08x\n",
rdz_32(BIOS_INT13), rdz_32(BIOS_INT15), rdz_32(BIOS_INT1E));
/* Figure out entry point */
if (!boot_seg) {
boot_base = 0x7c00;
shdr->sssp = 0x7c00;
shdr->csip = 0x7c00;
} else {
boot_base = boot_seg << 4;
shdr->sssp = boot_seg << 16;
shdr->csip = boot_seg << 16;
}
/* Relocate the real-mode code to below the stub */
rm_base = (driveraddr - rm_args.rm_size) & ~15;
if (rm_base < boot_base + boot_len)
die("MEMDISK: bootstrap too large to load\n");
relocate_rm_code(rm_base);
/* Reboot into the new "disk" */
puts("Loading boot sector... ");
memcpy((void *)boot_base,
(char *)pptr->mdi.diskbuf + geometry->boot_lba * 512,
boot_len);
if (getcmditem("pause") != CMD_NOTFOUND) {
puts("press any key to boot... ");
memset(&regs, 0, sizeof regs);
regs.eax.w[0] = 0;
intcall(0x16, &regs, NULL);
}
puts("booting...\n");
/* On return the assembly code will jump to the boot vector */
shdr->esdi = pnp_install_check();
shdr->edx = geometry->driveno;
}
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