|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [HVM] Add expansion-ROM boot support to the ROMBIOS
# HG changeset patch
# User Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
# Date 1166615873 0
# Node ID e2fcb70bec59f49f06fdccc8e417d1096b391af1
# Parent caa1987679bddcb330e87adf787936ab94162e8d
[HVM] Add expansion-ROM boot support to the ROMBIOS
This is rudimentary support for parts of the BIOS Boot Specification,
just enough to use Etherboot ROM images.
Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
---
tools/firmware/rombios/rombios.c | 441 ++++++++++++++++++++++++---------------
tools/ioemu/hw/pc.c | 2
tools/ioemu/vl.c | 2
3 files changed, 280 insertions(+), 165 deletions(-)
diff -r caa1987679bd -r e2fcb70bec59 tools/firmware/rombios/rombios.c
--- a/tools/firmware/rombios/rombios.c Wed Dec 20 11:54:57 2006 +0000
+++ b/tools/firmware/rombios/rombios.c Wed Dec 20 11:57:53 2006 +0000
@@ -278,7 +278,6 @@ typedef unsigned short bx_bool;
typedef unsigned short bx_bool;
typedef unsigned long Bit32u;
-#if BX_USE_ATADRV
void memsetb(seg,offset,value,count);
void memcpyb(dseg,doffset,sseg,soffset,count);
@@ -418,7 +417,6 @@ typedef unsigned long Bit32u;
ASM_END
}
#endif
-#endif //BX_USE_ATADRV
// read_dword and write_dword functions
static Bit32u read_dword();
@@ -885,7 +883,7 @@ static void int15_function();
static void int15_function();
static void int16_function();
static void int17_function();
-static Bit32u int19_function();
+static void int19_function();
static void int1a_function();
static void int70_function();
static void int74_function();
@@ -1847,28 +1845,99 @@ print_bios_banner()
printf("\n");
}
+
+//--------------------------------------------------------------------------
+// BIOS Boot Specification 1.0.1 compatibility
+//
+// Very basic support for the BIOS Boot Specification, which allows expansion
+// ROMs to register themselves as boot devices, instead of just stealing the
+// INT 19h boot vector.
+//
+// This is a hack: to do it properly requires a proper PnP BIOS and we aren't
+// one; we just lie to the option ROMs to make them behave correctly.
+// We also don't support letting option ROMs register as bootable disk
+// drives (BCVs), only as bootable devices (BEVs).
+//
+//
http://www.phoenix.com/en/Customer+Services/White+Papers-Specs/pc+industry+specifications.htm
+//--------------------------------------------------------------------------
+
+/* 256 bytes at 0x0600 -- 0x06ff is used for the IPL boot table. This
+ * ought really to be in NVRAM somewhere where a failed boot attempt can't
+ * corrupt it. */
+#define IPL_SEG 0x0060
+#define IPL_TABLE_OFFSET 0x0000
+#define IPL_TABLE_ENTRIES 8
+#define IPL_COUNT_OFFSET 0x0080
+
+struct ipl_entry {
+ Bit16u type;
+ Bit16u flags;
+ Bit32u vector;
+ Bit32u description;
+ Bit32u reserved;
+};
+
+static void
+init_boot_vectors()
+{
+ struct ipl_entry e;
+ Bit16u count = 0;
+ Bit16u ss = get_SS();
+
+ /* Clear out the IPL table. */
+ memsetb(IPL_SEG, IPL_TABLE_OFFSET, 0, 0xff);
+
+ /* Floppy drive */
+ e.type = 1; e.flags = 0; e.vector = 0; e.description = 0; e.reserved = 0;
+ memcpyb(IPL_SEG, IPL_TABLE_OFFSET + count * sizeof (e), ss, &e, sizeof (e));
+ count++;
+
+ /* First HDD */
+ e.type = 2; e.flags = 0; e.vector = 0; e.description = 0; e.reserved = 0;
+ memcpyb(IPL_SEG, IPL_TABLE_OFFSET + count * sizeof (e), ss, &e, sizeof (e));
+ count++;
+
+#if BX_ELTORITO_BOOT
+ /* CDROM */
+ e.type = 3; e.flags = 0; e.vector = 0; e.description = 0; e.reserved = 0;
+ memcpyb(IPL_SEG, IPL_TABLE_OFFSET + count * sizeof (e), ss, &e, sizeof (e));
+ count++;
+#endif
+
+ /* Remember how many devices we have */
+ write_word(IPL_SEG, IPL_COUNT_OFFSET, count);
+}
+
+static Bit8u
+get_boot_vector(i, e)
+Bit16u i; struct ipl_entry *e;
+{
+ Bit16u count;
+ Bit16u ss = get_SS();
+ /* Get the count of boot devices, and refuse to overrun the array */
+ count = read_word(IPL_SEG, IPL_COUNT_OFFSET);
+ if (i >= count) return 0;
+ /* OK to read this device */
+ memcpyb(ss, e, IPL_SEG, IPL_TABLE_OFFSET + i * sizeof (*e), sizeof (*e));
+ return 1;
+}
+
+
//--------------------------------------------------------------------------
// print_boot_device
// displays the boot device
//--------------------------------------------------------------------------
-static char drivetypes[][10]={"Floppy","Hard Disk","CD-Rom"};
+static char drivetypes[][10]={"", "Floppy","Hard Disk","CD-Rom", "Network"};
void
-print_boot_device(cdboot, drive)
- Bit8u cdboot; Bit16u drive;
+print_boot_device(type)
+ Bit16u type;
{
- Bit8u i;
-
- // cdboot contains 0 if floppy/harddisk, 1 otherwise
- // drive contains real/emulated boot drive
-
- if(cdboot)i=2; // CD-Rom
- else if((drive&0x0080)==0x00)i=0; // Floppy
- else if((drive&0x0080)==0x80)i=1; // Hard drive
- else return;
-
- printf("Booting from %s...\n",drivetypes[i]);
+ /* NIC appears as type 0x80 */
+ if (type == 0x80 ) type = 0x4;
+ if (type == 0 || type > 0x4) BX_PANIC("Bad drive type\n");
+ printf("Booting from %s...\n", drivetypes[type]);
}
//--------------------------------------------------------------------------
@@ -1876,29 +1945,20 @@ print_boot_device(cdboot, drive)
// displays the reason why boot failed
//--------------------------------------------------------------------------
void
-print_boot_failure(cdboot, drive, reason, lastdrive)
- Bit8u cdboot; Bit8u drive; Bit8u lastdrive;
+print_boot_failure(type, reason)
+ Bit16u type; Bit8u reason;
{
- Bit16u drivenum = drive&0x7f;
-
- // cdboot: 1 if boot from cd, 0 otherwise
- // drive : drive number
- // reason: 0 signature check failed, 1 read error
- // lastdrive: 1 boot drive is the last one in boot sequence
-
- if (cdboot)
- bios_printf(BIOS_PRINTF_INFO | BIOS_PRINTF_SCREEN, "Boot from %s
failed\n",drivetypes[2]);
- else if (drive & 0x80)
- bios_printf(BIOS_PRINTF_INFO | BIOS_PRINTF_SCREEN, "Boot from %s %d
failed\n", drivetypes[1],drivenum);
+ if (type == 0 || type > 0x3) BX_PANIC("Bad drive type\n");
+
+ printf("Boot from %s failed", drivetypes[type]);
+ if (type < 4) {
+ /* Report the reason too */
+ if (reason==0)
+ printf(": not a bootable disk");
else
- bios_printf(BIOS_PRINTF_INFO | BIOS_PRINTF_SCREEN, "Boot from %s %d
failed\n", drivetypes[0],drivenum);
-
- if (lastdrive==1) {
- if (reason==0)
- BX_PANIC("Not a bootable disk\n");
- else
- BX_PANIC("Could not read the boot disk\n");
+ printf(": could not read the boot disk");
}
+ printf("\n");
}
//--------------------------------------------------------------------------
@@ -7546,19 +7606,19 @@ int17_function(regs, ds, iret_addr)
}
}
-// returns bootsegment in ax, drive in bl
- Bit32u
-int19_function(bseqnr)
-Bit8u bseqnr;
+void
+int19_function(seq_nr)
+Bit16u seq_nr;
{
Bit16u ebda_seg=read_word(0x0040,0x000E);
- Bit16u bootseq;
+ Bit16u bootdev;
Bit8u bootdrv;
- Bit8u bootcd;
Bit8u bootchk;
Bit16u bootseg;
+ Bit16u bootip;
Bit16u status;
- Bit8u lastdrive=0;
+
+ struct ipl_entry e;
// if BX_ELTORITO_BOOT is not defined, old behavior
// check bit 5 in CMOS reg 0x2d. load either 0x00 or 0x80 into DL
@@ -7575,54 +7635,43 @@ Bit8u bseqnr;
// 0x01 : first floppy
// 0x02 : first harddrive
// 0x03 : first cdrom
+ // 0x04 - 0x10 : PnP expansion ROMs (e.g. Etherboot)
// else : boot failure
// Get the boot sequence
#if BX_ELTORITO_BOOT
- bootseq=inb_cmos(0x3d);
- bootseq|=((inb_cmos(0x38) & 0xf0) << 4);
-
- if (bseqnr==2) bootseq >>= 4;
- if (bseqnr==3) bootseq >>= 8;
- if (bootseq<0x10) lastdrive = 1;
- bootdrv=0x00; bootcd=0;
- switch(bootseq & 0x0f) {
- case 0x01: bootdrv=0x00; bootcd=0; break;
- case 0x02: bootdrv=0x80; bootcd=0; break;
- case 0x03: bootdrv=0x00; bootcd=1; break;
- default: return 0x00000000;
- }
-#else
- bootseq=inb_cmos(0x2d);
-
- if (bseqnr==2) {
- bootseq ^= 0x20;
- lastdrive = 1;
+ bootdev = inb_cmos(0x3d);
+ bootdev |= ((inb_cmos(0x38) & 0xf0) << 4);
+ bootdev >>= 4 * seq_nr;
+ bootdev &= 0xf;
+ if (bootdev == 0) BX_PANIC("No bootable device.\n");
+
+ /* Translate from CMOS runes to an IPL table offset by subtracting 1 */
+ bootdev -= 1;
+#else
+ if (seq_nr ==2) BX_PANIC("No more boot devices.");
+ if (!!(inb_cmos(0x2d) & 0x20) ^ (seq_nr == 1))
+ /* Floppy first if the bit is set or it's the second boot */
+ bootdev = 0x00;
+ else
+ bootdev = 0x01;
+#endif
+
+ /* Read the boot device from the IPL table */
+ if (get_boot_vector(bootdev, &e) == 0) {
+ BX_INFO("Invalid boot device (0x%x)\n", bootdev);
+ return;
}
- bootdrv=0x00; bootcd=0;
- if((bootseq&0x20)==0) bootdrv=0x80;
-#endif // BX_ELTORITO_BOOT
-
-#if BX_ELTORITO_BOOT
- // We have to boot from cd
- if (bootcd != 0) {
- status = cdrom_boot();
-
- // If failure
- if ( (status & 0x00ff) !=0 ) {
- print_cdromboot_failure(status);
- print_boot_failure(bootcd, bootdrv, 1, lastdrive);
- return 0x00000000;
- }
-
- bootseg = read_word(ebda_seg,&EbdaData->cdemu.load_segment);
- bootdrv = (Bit8u)(status>>8);
- }
-
-#endif // BX_ELTORITO_BOOT
-
- // We have to boot from harddisk or floppy
- if (bootcd == 0) {
+
+ /* Do the loading, and set up vector as a far pointer to the boot
+ * address, and bootdrv as the boot drive */
+ print_boot_device(e.type);
+
+ switch(e.type) {
+ case 0x01: /* FDD */
+ case 0x02: /* HDD */
+
+ bootdrv = (e.type == 0x02) ? 0x80 : 0x00;
bootseg=0x07c0;
ASM_START
@@ -7650,39 +7699,71 @@ ASM_END
ASM_END
if (status != 0) {
- print_boot_failure(bootcd, bootdrv, 1, lastdrive);
- return 0x00000000;
+ print_boot_failure(e.type, 1);
+ return;
+ }
+
+ // check signature if instructed by cmos reg 0x38, only for floppy
+ if (e.type == 0x00 && (inb_cmos(0x38) & 0x01)) {
+ if (read_word(bootseg,0x1fe) != 0xaa55) {
+ print_boot_failure(e.type, 0);
+ return;
}
}
- // check signature if instructed by cmos reg 0x38, only for floppy
- // bootchk = 1 : signature check disabled
- // bootchk = 0 : signature check enabled
- if (bootdrv != 0) bootchk = 0;
- else bootchk = inb_cmos(0x38) & 0x01;
+ /* Canonicalize bootseg:bootip */
+ bootip = (bootseg & 0x0fff) << 4;
+ bootseg &= 0xf000;
+ break;
#if BX_ELTORITO_BOOT
- // if boot from cd, no signature check
- if (bootcd != 0)
- bootchk = 1;
-#endif // BX_ELTORITO_BOOT
-
- if (bootchk == 0) {
- if (read_word(bootseg,0x1fe) != 0xaa55) {
- print_boot_failure(bootcd, bootdrv, 0, lastdrive);
- return 0x00000000;
- }
+ case 0x03: /* CD-ROM */
+ status = cdrom_boot();
+
+ // If failure
+ if ( (status & 0x00ff) !=0 ) {
+ print_cdromboot_failure(status);
+ print_boot_failure(e.type, 1);
+ return;
}
+
+ bootdrv = (Bit8u)(status>>8);
+ bootseg = read_word(ebda_seg,&EbdaData->cdemu.load_segment);
+ /* Canonicalize bootseg:bootip */
+ bootip = (bootseg & 0x0fff) << 4;
+ bootseg &= 0xf000;
+ break;
+#endif
+
+ case 0x80: /* Expansion ROM with a Bootstrap Entry Vector (a far pointer) */
+ bootseg = e.vector >> 16;
+ bootip = e.vector & 0xffff;
+ break;
+
+ default: return;
+ }
-#if BX_ELTORITO_BOOT
- // Print out the boot string
- print_boot_device(bootcd, bootdrv);
-#else // BX_ELTORITO_BOOT
- print_boot_device(0, bootdrv);
-#endif // BX_ELTORITO_BOOT
-
- // return the boot segment
- return (((Bit32u)bootdrv) << 16) + bootseg;
+ /* Jump to the boot vector */
+ASM_START
+ mov bp, sp
+ ;; Build an iret stack frame that will take us to the boot vector.
+ ;; iret pops ip, then cs, then flags, so push them in the opposite order.
+ pushf
+ mov ax, _int19_function.bootseg + 0[bp]
+ push ax
+ mov ax, _int19_function.bootip + 0[bp]
+ push ax
+ ;; Set the magic number in ax and the boot drive in dl.
+ mov ax, #0xaa55
+ mov dl, _int19_function.bootdrv + 0[bp]
+ ;; Zero some of the other registers.
+ xor bx, bx
+ mov ds, bx
+ mov es, bx
+ mov bp, bx
+ ;; Go!
+ iret
+ASM_END
}
void
@@ -8139,14 +8220,26 @@ int13_out:
popa
iret
-
;----------
;- INT18h -
;----------
-int18_handler: ;; Boot Failure routing
- call _int18_panic_msg
- hlt
- iret
+int18_handler: ;; Boot Failure recovery: try the next device.
+
+ ;; Reset DS, SS and SP
+ xor ax, ax
+ mov ds, ax
+ mov ss, ax
+ mov ax, #0xfffe
+ mov sp, ax
+
+ ;; Get the boot sequence number off the top of the stack
+ sub sp, #2
+ pop ax
+ ;; Increment the boot sequence number, and carry on in the INT 19h handler
+ inc ax
+ push ax
+
+ jmp int19_next_boot
;----------
;- INT19h -
@@ -8160,56 +8253,25 @@ int19_relocated: ;; Boot function, reloc
push bp
mov bp, sp
-
- ;; drop ds
+
+ ;; Reset DS, SS and SP
xor ax, ax
mov ds, ax
-
- ;; 1st boot device
- mov ax, #0x0001
+ mov ss, ax
+ mov ax, #0xfffe
+ mov sp, ax
+
+ ;; Start from the first boot device.
+ mov ax, #0000
push ax
+
+int19_next_boot:
+
+ ;; Call the C code for the next boot device
call _int19_function
- inc sp
- inc sp
- ;; bl contains the boot drive
- ;; ax contains the boot segment or 0 if failure
-
- test ax, ax ;; if ax is 0 try next boot device
- jnz boot_setup
-
- ;; 2nd boot device
- mov ax, #0x0002
- push ax
- call _int19_function
- inc sp
- inc sp
- test ax, ax ;; if ax is 0 try next boot device
- jnz boot_setup
-
- ;; 3rd boot device
- mov ax, #0x0003
- push ax
- call _int19_function
- inc sp
- inc sp
- test ax, ax ;; if ax is 0 call int18
- jz int18_handler
-
-boot_setup:
- mov dl, bl ;; set drive so guest os find it
- shl eax, #0x04 ;; convert seg to ip
- mov 2[bp], ax ;; set ip
-
- shr eax, #0x04 ;; get cs back
- and ax, #0xF000 ;; remove what went in ip
- mov 4[bp], ax ;; set cs
- xor ax, ax
- mov es, ax ;; set es to zero fixes [ 549815 ]
- mov [bp], ax ;; set bp to zero
- mov ax, #0xaa55 ;; set ok flag
-
- pop bp
- iret ;; Beam me up Scotty
+
+ ;; Boot failed: invoke the boot recovery function
+ int #0x18
;----------
;- INT1Ch -
@@ -9387,6 +9449,15 @@ checksum_loop:
pop ax
ret
+
+;; We need a copy of this string, but we are not actually a PnP BIOS,
+;; so make sure it is *not* aligned, so OSes will not see it if they scan.
+.align 16
+ db 0
+pnp_string:
+ .ascii "$PnP"
+
+
rom_scan:
;; Scan for existence of valid expansion ROMS.
;; Video ROM: from 0xC0000..0xC7FFF in 2k increments
@@ -9421,9 +9492,17 @@ block_count_rounded:
xor bx, bx ;; Restore DS back to 0000:
mov ds, bx
push ax ;; Save AX
+ push di ;; Save DI
;; Push addr of ROM entry point
push cx ;; Push seg
push #0x0003 ;; Push offset
+
+ ;; Point ES:DI at "$PnP", which tells the ROM that we are a PnP BIOS.
+ ;; That should stop it grabbing INT 19h; we will use its BEV instead.
+ mov ax, #0xf000
+ mov es, ax
+ lea di, pnp_string
+
mov bp, sp ;; Call ROM init routine using seg:off on stack
db 0xff ;; call_far ss:[bp+0]
db 0x5e
@@ -9431,6 +9510,38 @@ block_count_rounded:
cli ;; In case expansion ROM BIOS turns IF on
add sp, #2 ;; Pop offset value
pop cx ;; Pop seg value (restore CX)
+
+ ;; Look at the ROM's PnP Expansion header. Properly, we're supposed
+ ;; to init all the ROMs and then go back and build an IPL table of
+ ;; all the bootable devices, but we can get away with one pass.
+ mov ds, cx ;; ROM base
+ mov bx, 0x001a ;; 0x1A is the offset into ROM header that contains...
+ mov ax, [bx] ;; the offset of PnP expansion header, where...
+ cmp ax, #0x5024 ;; we look for signature "$PnP"
+ jne no_bev
+ mov ax, 2[bx]
+ cmp ax, #0x506e
+ jne no_bev
+ mov ax, 0x1a[bx] ;; 0x1A is also the offset into the expansion header of...
+ cmp ax, #0x0000 ;; the Bootstrap Entry Vector, or zero if there is none.
+ je no_bev
+
+ ;; Found a device that thinks it can boot the system. Record its BEV.
+ mov bx, #IPL_SEG ;; Go to the segment where the IPL table lives
+ mov ds, bx
+ mov bx, IPL_COUNT_OFFSET ;; Read the number of entries so far
+ cmp bx, #IPL_TABLE_ENTRIES
+ je no_bev ;; Get out if the table is full
+ shl bx, #0x4 ;; Turn count into offset (entries are 16 bytes)
+ mov 0[bx], #0x80 ;; This entry is a BEV device
+ mov 6[bx], cx ;; Build a far pointer from the segment...
+ mov 4[bx], ax ;; and the offset
+ shr bx, #0x4 ;; Turn the offset back into a count
+ inc bx ;; We have one more entry now
+ mov IPL_COUNT_OFFSET, bx ;; Remember that.
+
+no_bev:
+ pop di ;; Restore DI
pop ax ;; Restore AX
rom_scan_increment:
shl ax, #5 ;; convert 512-bytes blocks to 16-byte increments
@@ -9763,6 +9874,8 @@ post_default_ints:
call _copy_e820_table
call smbios_init
#endif
+
+ call _init_boot_vectors
call rom_scan
diff -r caa1987679bd -r e2fcb70bec59 tools/ioemu/hw/pc.c
--- a/tools/ioemu/hw/pc.c Wed Dec 20 11:54:57 2006 +0000
+++ b/tools/ioemu/hw/pc.c Wed Dec 20 11:57:53 2006 +0000
@@ -168,6 +168,8 @@ static int get_bios_disk(char *boot_devi
return 0x02; /* hard drive */
case 'd':
return 0x03; /* cdrom */
+ case 'n':
+ return 0x04; /* network */
}
}
return 0x00; /* no device */
diff -r caa1987679bd -r e2fcb70bec59 tools/ioemu/vl.c
--- a/tools/ioemu/vl.c Wed Dec 20 11:54:57 2006 +0000
+++ b/tools/ioemu/vl.c Wed Dec 20 11:57:53 2006 +0000
@@ -6153,7 +6153,7 @@ int main(int argc, char **argv)
case QEMU_OPTION_boot:
boot_device = strdup(optarg);
if (strspn(boot_device, "acd"
-#ifdef TARGET_SPARC
+#if defined(TARGET_SPARC) || defined(TARGET_I386)
"n"
#endif
) != strlen(boot_device)) {
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |