Extended Bios Data Area (EBDA) can be relocated by the initialization
of PCI option ROM. The IPL boot table is also.
EBDA must be accessed via 0x40E after the initialization.
Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>
diff -r 045f70d1acdb tools/firmware/rombios/rombios.c
--- a/tools/firmware/rombios/rombios.c Sat Dec 13 17:44:20 2008 +0000
+++ b/tools/firmware/rombios/rombios.c Mon Dec 15 13:51:59 2008 +0900
@@ -182,6 +182,12 @@
#define EBDA_SEG 0x9FC0
#define EBDA_SIZE 1 // In KiB
#define BASE_MEM_IN_K (640 - EBDA_SIZE)
+
+/* 256 bytes at 0x9ff00 -- 0x9ffff is used for the IPL boot table. */
+#define IPL_TABLE_OFFSET 0x0300 /* offset from EBDA */
+#define IPL_TABLE_ENTRIES 8
+#define IPL_COUNT_OFFSET 0x0380 /* u16: number of valid table entries */
+#define IPL_SEQUENCE_OFFSET 0x0382 /* u16: next boot device */
// Define the application NAME
#ifdef HVMASSIST
@@ -1963,13 +1969,6 @@ print_bios_banner()
//
http://www.phoenix.com/en/Customer+Services/White+Papers-Specs/pc+industry+specifications.htm
//--------------------------------------------------------------------------
-/* 256 bytes at 0x9ff00 -- 0x9ffff is used for the IPL boot table. */
-#define IPL_SEG 0x9ff0
-#define IPL_TABLE_OFFSET 0x0000
-#define IPL_TABLE_ENTRIES 8
-#define IPL_COUNT_OFFSET 0x0080 /* u16: number of valid table entries */
-#define IPL_SEQUENCE_OFFSET 0x0082 /* u16: next boot device */
-
struct ipl_entry {
Bit16u type;
Bit16u flags;
@@ -1986,29 +1985,29 @@ init_boot_vectors()
Bit16u ss = get_SS();
/* Clear out the IPL table. */
- memsetb(IPL_SEG, IPL_TABLE_OFFSET, 0, 0xff);
+ memsetb(EBDA_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));
+ memcpyb(EBDA_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));
+ memcpyb(EBDA_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));
+ memcpyb(EBDA_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);
+ write_word(EBDA_SEG, IPL_COUNT_OFFSET, count);
/* Not tried booting anything yet */
- write_word(IPL_SEG, IPL_SEQUENCE_OFFSET, 0xffff);
+ write_word(EBDA_SEG, IPL_SEQUENCE_OFFSET, 0xffff);
}
static Bit8u
@@ -2017,11 +2016,12 @@ Bit16u i; struct ipl_entry *e;
{
Bit16u count;
Bit16u ss = get_SS();
+ Bit16u ebda_seg = read_word(0x0040, 0x000E);
/* Get the count of boot devices, and refuse to overrun the array */
- count = read_word(IPL_SEG, IPL_COUNT_OFFSET);
+ count = read_word(ebda_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));
+ memcpyb(ss, e, ebda_seg, IPL_TABLE_OFFSET + i * sizeof (*e), sizeof (*e));
return 1;
}
@@ -2187,9 +2187,10 @@ int bootmenu(selected)
{
Bit8u scode;
int max;
+ Bit16u ebda_seg = read_word(0x0040, 0x000E);
/* get the number of boot devices */
- max = read_word(IPL_SEG, IPL_COUNT_OFFSET);
+ max = read_word(ebda_seg, IPL_COUNT_OFFSET);
for(;;) {
if (selected > max || selected < 1) selected = 1;
@@ -2349,7 +2350,9 @@ ASM_START
ASM_START
push ds
push ax
- mov ax, #EBDA_SEG
+ xor ax, ax
+ mov ds, ax
+ mov ax, word ptr [0x40E] ;; EBDA segment
mov ds, ax
mov al, [EBDA_CMOS_SHUTDOWN_STATUS_OFFSET]
mov .s3_resume.cmos_shutdown_status[bp], al
@@ -8543,7 +8546,8 @@ int18_handler: ;; Boot Failure recovery:
;; Get the boot sequence number out of the IPL memory
;; The first time we do this it will have been set to -1 so
;; we will start from device 0.
- mov bx, #IPL_SEG
+ mov ds, ax
+ mov bx, word ptr [0x40E] ;; EBDA segment
mov ds, bx ;; Set segment
mov bx, IPL_SEQUENCE_OFFSET ;; BX is now the sequence number
inc bx ;; ++
@@ -8686,8 +8690,8 @@ hard_drive_post:
SET_INT_VECTOR(0x76, #0xF000, #int76_handler)
;; INT 41h: hard disk 0 configuration pointer
;; INT 46h: hard disk 1 configuration pointer
- SET_INT_VECTOR(0x41, #EBDA_SEG, #0x003D)
- SET_INT_VECTOR(0x46, #EBDA_SEG, #0x004D)
+ SET_INT_VECTOR(0x41, word ptr [0x40E], #0x003D) /* EBDA:003D */
+ SET_INT_VECTOR(0x46, word ptr [0x40E], #0x004D) /* EBDA:004D */
;; move disk geometry data from CMOS to EBDA disk parameter table(s)
mov al, #0x12
@@ -8716,7 +8720,9 @@ post_d0_type47:
;; 22 landing zone high D
;; 23 sectors/track E
- mov ax, #EBDA_SEG
+ xor ax, ax
+ mov ds, ax
+ mov ax, word ptr [0x40E] ;; EBDA segment
mov ds, ax
;;; Filling EBDA table for hard disk 0.
@@ -9754,15 +9760,17 @@ no_bcv:
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
+ xor bx, bx
mov ds, bx
+ mov bx, word ptr [0x40E] ;; EBDA segment
+ mov ds, bx ;; Go to the segment where the IPL table lives
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
+ mov IPL_TABLE_OFFSET+0[bx], #0x80 ;; This entry is a BEV device
+ mov IPL_TABLE_OFFSET+6[bx], cx ;; Build a far pointer from the segment...
+ mov IPL_TABLE_OFFSET+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.
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