More Compaq-specific tweaks
This commit is contained in:
Jeff Parsons
jeffpar
parent
9b1de72137
commit
b9252390bf
6 changed files with 339 additions and 179 deletions
|
|
@ -7,7 +7,9 @@
|
|||
; Additional post-processing performed by the PCjs TextOut module
|
||||
; All post-processing, comments, etc copyright © 2012-2015 Jeff Parsons <Jeff@pcjs.org>
|
||||
;
|
||||
; NOTE: This 32Kb ROM image is ORG'ed at 0x8000, because it needs to run at real-mode
|
||||
; Overview
|
||||
; --------
|
||||
; This 32Kb ROM image is ORG'ed at 0x8000, because it needs to run at real-mode
|
||||
; addresses F000:8000 through F000:FFFF, as well as protected-mode physical addresses
|
||||
; %FFFF8000 through %FFFFFFFF. Additionally, DeskPro 386 systems mirror this 32Kb ROM
|
||||
; at real-mode addresses F000:0000 through F000:7FFF, as well as protected-mode physical
|
||||
|
|
@ -20,16 +22,44 @@
|
|||
; %FE0000 through %FFFFFF to be mapped to %0E0000 through %0FFFFF, effectively replacing
|
||||
; the ROM in the first megabyte with write-protected RAM; the top 64Kb of that RAM must
|
||||
; first be initialized with the 64Kb at %0F0000 prior to remapping. It's also possible
|
||||
; to copy external ROMs from %0E0000 through %0EFFFF into the bottom 64Kb of that RAM, but
|
||||
; this is only done for ROMs known to contain relocatable code (eg, a Compaq Enhanced
|
||||
; to copy external ROMs from %0C0000 through %0EFFFF into the bottom 64Kb of that RAM,
|
||||
; but this is only done for ROMs known to contain relocatable code (eg, a Compaq Enhanced
|
||||
; Video Graphics card).
|
||||
;
|
||||
; Every DeskPro 386 system must have a MINIMUM of 1Mb of RAM, of which either 256Kb, 512Kb,
|
||||
; or 640Kb can be physically mapped as conventional memory (at the bottom of the first
|
||||
; megabyte), with the remainder (either 768Kb, 512Kb, or 384Kb) physically mapped to the
|
||||
; top of the 16th megabyte (ending at address %FFFFFF), the last 128Kb of which is
|
||||
; used by the "RAM Relocation" feature. The remaining memory immediately below that
|
||||
; Every DeskPro 386 system must have a MINIMUM of 1Mb of RAM, of which either 256Kb,
|
||||
; 512Kb, or 640Kb can be physically mapped as conventional memory (at the bottom of the
|
||||
; first megabyte), with the remainder (either 768Kb, 512Kb, or 384Kb) physically mapped
|
||||
; to the top of the 16th megabyte (ending at address %FFFFFF), the last 128Kb of which
|
||||
; is used by the "RAM Relocation" feature. The remaining memory immediately below that
|
||||
; 128Kb (ie, below %FE0000) can only be accessed by special system software, such as CEMM.
|
||||
;
|
||||
; Compaq refers to that remaining memory as "Compaq Built-in Memory".
|
||||
;
|
||||
; As the Compaq 386/25 TechRef explains:
|
||||
;
|
||||
; A data structure in memory indicates how much of the COMPAQ Built-in Memory (F40000h
|
||||
; to FE0000h) is [available and] in use. This memory is allocated downward (decreasing
|
||||
; addresses) starting at address FE0000h. Applications developed specifically for the
|
||||
; COMPAQ DESKPRO 386/25 Personal Computer, such as CEMM, read and modify this data
|
||||
; structure to allocate and deallocate portions of the COMPAQ Built-in Memory for their
|
||||
; use. The built-in memory data structure is located in write-protected memory at segment
|
||||
; F000h. The offset is specified by the word at F000:FFE0.
|
||||
;
|
||||
; The format of the data structure is given [below]. Because the data structure resides
|
||||
; in write-protected memory, the write-protection must be disabled when updating the data
|
||||
; structure.
|
||||
;
|
||||
; Word Description
|
||||
; ---- -----------
|
||||
; 0 FFFFh indicates that no COMPAQ Built-in Memory is available. Otherwise, words
|
||||
; 1, 2, and 3 define the amount of memory available.
|
||||
;
|
||||
; 1 Total COMPAQ Built-in Memory size in 16-byte blocks.
|
||||
;
|
||||
; 2 Available built-in memory in 16-byte blocks.
|
||||
;
|
||||
; 3 Address for the last-used byte. The byte below (lower address) this byte is the
|
||||
; first free byte in the COMPAQ Built-in Memory.
|
||||
;
|
||||
org 0x8000
|
||||
|
||||
|
|
@ -98,6 +128,7 @@ x8051: push bx ; 00008051 53 'S'
|
|||
push bp ; 00008053 55 'U'
|
||||
mov dl,al ; 00008054 8AD0 '..'
|
||||
mov bp,es ; 00008056 8CC5 '..'
|
||||
|
||||
;;
|
||||
;; 0x4C is the base portion of the descriptor at DS:0x48
|
||||
;;
|
||||
|
|
@ -738,16 +769,18 @@ x853c: mov al,0x7f ; 0000853C B07F '..'
|
|||
cld ; 0000858F FC '.'
|
||||
rep movsd ; 00008590 66F3A5 'f..'
|
||||
|
||||
mov bx,rombuf1 ; 00008593 BBE0FF '...'
|
||||
;;
|
||||
;; (DI) -> 0x7FB6
|
||||
;;
|
||||
mov bx,bim_table_offset ; 00008593 BBE0FF '...'
|
||||
mov di,[bx] ; 00008596 8B3F '.?'
|
||||
|
||||
;;
|
||||
;; (DI) == 0x7FB6
|
||||
;; (SI) -> 0x7FBE
|
||||
;;
|
||||
mov bx,rombuf2 ; 00008598 BBE2FF '...'
|
||||
mov bx,cpu_idrev_offset ; 00008598 BBE2FF '...'
|
||||
mov si,[bx] ; 0000859B 8B37 '.7'
|
||||
;;
|
||||
;; (SI) == 0x7FBE
|
||||
;;
|
||||
|
||||
pop ds ; 0000859D 1F '.'
|
||||
mov word [0x50],0xffff ; 0000859E C7065000FFFF '..P...'
|
||||
mov word [0x52],0x0 ; 000085A4 C70652000000 '..R...'
|
||||
|
|
@ -755,37 +788,58 @@ x853c: mov al,0x7f ; 0000853C B07F '..'
|
|||
mov byte [0x55],0x92 ; 000085AF C606550092 '..U..'
|
||||
mov byte [0x56],0x0 ; 000085B4 C606560000 '..V..'
|
||||
mov byte [0x57],0x80 ; 000085B9 C606570080 '..W..'
|
||||
mov bx,[0x8d] ; 000085BE 8B1E8D00 '....'
|
||||
|
||||
;;
|
||||
;; (BX) is 0x100 (256Kb)
|
||||
;;
|
||||
mov bx,[0x8d] ; 000085BE 8B1E8D00 '....'
|
||||
|
||||
push ds ; 000085C2 1E '.'
|
||||
mov ax,0x50 ; 000085C3 B85000 '.P.'
|
||||
mov ds,ax ; 000085C6 8ED8 '..'
|
||||
|
||||
;;
|
||||
;; (DS) -> 0x80C00000
|
||||
;;
|
||||
mov ax,0x50 ; 000085C3 B85000 '.P.'
|
||||
mov ds,ax ; 000085C6 8ED8 '..'
|
||||
|
||||
;;
|
||||
;; Disable IOCHK NMI, since it is possible to generate a
|
||||
;; parity error by simply reading the RAM Diagnostics Register.
|
||||
;;
|
||||
in al,0x61 ; 000085C8 E461 '.a'
|
||||
push ax ; 000085CA 50 'P'
|
||||
or al,0x8 ; 000085CB 0C08 '..'
|
||||
out 0x61,al ; 000085CD E661 '.a'
|
||||
|
||||
;;
|
||||
;; Load the RAM Diagnostics Register from 0x80C00000
|
||||
;; (AL) == RAM Diagnostics Register (from 0x80C00000)
|
||||
;;
|
||||
mov al,[0x0] ; 000085CF A00000 '...'
|
||||
|
||||
;;
|
||||
;; Ensure that relocatable RAM at %FE0000 is NEITHER currently remapped NOR write-protected
|
||||
;;
|
||||
mov byte [0x0],0xff ; 000085D2 C6060000FF '.....'
|
||||
|
||||
;;
|
||||
;; Isolate the base memory settings in bits 5-4 (00=640Kb, 10=512Kb, 11=256Kb)
|
||||
;;
|
||||
and al,0xf0 ; 000085D7 24F0 '$.'
|
||||
|
||||
;;
|
||||
;; Update %FF7FB7 with base memory settings
|
||||
;; Update [bim_table_offset]+1 (eg, %FF7FB7) with base memory settings
|
||||
;;
|
||||
mov [es:di+0x1],al ; 000085D9 26884501 '&.E.'
|
||||
pop ax ; 000085DD 58 'X'
|
||||
out 0x61,al ; 000085DE E661 '.a'
|
||||
|
||||
;;
|
||||
;; Update %FF7FB6 with 0x10
|
||||
;; Update [bim_table_offset]+0 (eg, %FF7FB6) with 0x10; that will set the
|
||||
;; first word of the built-in memory table to one of these values:
|
||||
;;
|
||||
;; 0x0010 256kb (1024 - 640 - 128)
|
||||
;; 0x2010 384Kb (1024 - 512 - 128)
|
||||
;; 0x3010 640Kb (1024 - 256 - 128)
|
||||
;;
|
||||
mov byte [es:di],0x10 ; 000085E0 26C60510
|
||||
|
||||
|
|
@ -796,40 +850,54 @@ x853c: mov al,0x7f ; 0000853C B07F '..'
|
|||
mov al,0xb0 ; 000085EC B0B0 '..'
|
||||
out 0x70,al ; 000085EE E670 '.p'
|
||||
in al,0x71 ; 000085F0 E471 '.q'
|
||||
|
||||
;;
|
||||
;; (AX) contains CMOS EXTMEM2 value (0x400)
|
||||
;; (AX) contains CMOS EXTMEM2 value (eg, 0x400 or 1024Kb),
|
||||
;; to which we add another 1024Kb (for conventional memory)
|
||||
;;
|
||||
add ax,0x400 ; 000085F2 050004 '...'
|
||||
mov cx,0x3f80 ; 000085F5 B9803F '..?'
|
||||
|
||||
;;
|
||||
;; (CX) contains 0x3F80 (maximum # of supported Kb)
|
||||
;; (CX) contains 0x3F80 (maximum # of supported Kb), reduced
|
||||
;; by the amount of built-in memory
|
||||
;;
|
||||
sub cx,bx ; 000085F8 2BCB '+.'
|
||||
|
||||
;;
|
||||
;; Compare (AX), total conventional+extended memory, to (CX)
|
||||
;;
|
||||
cmp ax,cx ; 000085FA 3BC1 ';.'
|
||||
jc x8600 ; 000085FC 7202 'r.'
|
||||
xor bx,bx ; 000085FE 33DB '3.'
|
||||
x8600: shl bx,0x6 ; 00008600 C1E306 '...'
|
||||
|
||||
;;
|
||||
;; Move 0x4000 to %FF7FB8 and %FF7FBA
|
||||
;; Assuming no problems, convert Kb of built-in memory to paragraphs,
|
||||
;; by multiplying by 64
|
||||
;;
|
||||
x8600: shl bx,0x6 ; 00008600 C1E306 '...'
|
||||
|
||||
;;
|
||||
;; If (BX) was 0x100 (256Kb), we'll move the equivalent number of paragraphs
|
||||
;; (0x4000) to [bim_table_offset]+2 and +4 (eg, %FF7FB8 and %FF7FBA).
|
||||
;;
|
||||
mov [es:di+0x2],bx ; 00008603 26895D02 '&.].'
|
||||
mov [es:di+0x4],bx ; 00008607 26895D04 '&.].'
|
||||
mov ch,0xfe ; 0000860B B5FE '..'
|
||||
xor cl,cl ; 0000860D 32C9 '2.'
|
||||
shl cx,0x4 ; 0000860F C1E104 '...'
|
||||
|
||||
;;
|
||||
;; Move 0xE000 to %FF7FBC
|
||||
;; Move 0xE000 to [bim_table_offset]+6 (eg, %FF7FBC)
|
||||
;;
|
||||
mov [es:di+0x6],cx ; 00008612 26894D06 '&.M.'
|
||||
mov di,si ; 00008616 8BFE '..'
|
||||
mov ax,gs ; 00008618 8CE8 '..'
|
||||
|
||||
;;
|
||||
;; (AX) now contains the processor type and revision (AH=0x03, AL=0x04)
|
||||
;;
|
||||
;; Store the type in %FF7FBE and the revision in %FF7FBF
|
||||
;; (AX) contains the processor type and revision (AH=0x03, AL=0x04),
|
||||
;; which were preserved on reset in (GS); store them at the offset specified
|
||||
;; by cpu_idrev_offset (eg, type in %FF7FBE and revision in %FF7FBF).
|
||||
;;
|
||||
mov [es:di],ah ; 0000861A 268825 '&.%'
|
||||
mov [es:di+0x1],al ; 0000861D 26884501 '&.E.'
|
||||
|
|
@ -844,6 +912,7 @@ x862a: es lodsb ; 0000862A 26AC '&.'
|
|||
not ah ; 00008630 F6D4 '..'
|
||||
inc ah ; 00008632 FEC4 '..'
|
||||
mov [es:si],ah ; 00008634 268824 '&.$'
|
||||
|
||||
;;
|
||||
;; Relocate RAM at %FF0000 to %0F0000
|
||||
;;
|
||||
|
|
@ -4229,7 +4298,7 @@ xa544: push bx ; 0000A544 53 'S'
|
|||
mov byte [bx+0x5],0x92 ; 0000A564 C6470592 '.G..'
|
||||
mov ax,0x20 ; 0000A568 B82000 '. .'
|
||||
mov es,ax ; 0000A56B 8EC0 '..'
|
||||
mov bx,rombuf1 ; 0000A56D BBE0FF '...'
|
||||
mov bx,bim_table_offset ; 0000A56D BBE0FF '...'
|
||||
mov bx,[es:bx] ; 0000A570 268B1F '&..'
|
||||
test word [es:bx],0xf00 ; 0000A573 26F707000F '&....'
|
||||
jnz xa57f ; 0000A578 7505 'u.'
|
||||
|
|
@ -6310,11 +6379,11 @@ xbad3: cld ; 0000BAD3 FC '.'
|
|||
mov al,0xff ; 0000BAD9 B0FF '..'
|
||||
out 0x21,al ; 0000BADB E621 '.!'
|
||||
out 0xa1,al ; 0000BADD E6A1 '..'
|
||||
mov bx,rombuf1 ; 0000BADF BBE0FF '...'
|
||||
mov bx,bim_table_offset ; 0000BADF BBE0FF '...'
|
||||
mov bx,[bx] ; 0000BAE2 8B1F '..'
|
||||
test word [bx],0xf00 ; 0000BAE4 F707000F '....'
|
||||
jnz xbaf5 ; 0000BAE8 750B 'u.'
|
||||
mov bx,rombuf2 ; 0000BAEA BBE2FF '...'
|
||||
mov bx,cpu_idrev_offset ; 0000BAEA BBE2FF '...'
|
||||
mov bx,[bx] ; 0000BAED 8B1F '..'
|
||||
mov ax,[bx] ; 0000BAEF 8B07 '..'
|
||||
xchg al,ah ; 0000BAF1 86C4 '..'
|
||||
|
|
@ -10901,7 +10970,7 @@ xdf34: mov bx,0x2 ; 0000DF34 BB0200 '...'
|
|||
lea si,[si+0x18] ; 0000DF48 8D7418 '.t.'
|
||||
call xdfbc ; 0000DF4B E86E00 '.n.'
|
||||
mov si,bx ; 0000DF4E 8BF3 '..'
|
||||
mov di,rombuf1 ; 0000DF50 BFE0FF '...'
|
||||
mov di,bim_table_offset ; 0000DF50 BFE0FF '...'
|
||||
mov di,[cs:di] ; 0000DF53 2E8B3D '..='
|
||||
test word [cs:di],0xf00 ; 0000DF56 2EF705000F '.....'
|
||||
lea di,[si+0x38] ; 0000DF5B 8D7C38 '.|8'
|
||||
|
|
@ -11519,7 +11588,7 @@ xe7dc: ret ; 0000E7DC C3 '.'
|
|||
|
||||
sub al,0x2d ; 0000E7DD 2C2D ',-' (NOTE: This instruction doesn't appear reachable)
|
||||
|
||||
xe7df: mov si,rombuf1 ; 0000E7DF BEE0FF '...'
|
||||
xe7df: mov si,bim_table_offset ; 0000E7DF BEE0FF '...'
|
||||
mov si,[cs:si] ; 0000E7E2 2E8B34 '..4'
|
||||
mov ax,[cs:si] ; 0000E7E5 2E8B04 '...'
|
||||
test ax,0xf00 ; 0000E7E8 A9000F '...'
|
||||
|
|
@ -12646,7 +12715,7 @@ xf273: cmp bx,byte +0x0 ; 0000F273 83FB00 '...'
|
|||
sub ax,bx ; 0000F287 2BC3 '+.'
|
||||
mov cx,0xf000 ; 0000F289 B900F0 '...'
|
||||
mov es,cx ; 0000F28C 8EC1 '..'
|
||||
mov di,rombuf1 ; 0000F28E BFE0FF '...'
|
||||
mov di,bim_table_offset ; 0000F28E BFE0FF '...'
|
||||
mov di,[es:di] ; 0000F291 268B3D '&.='
|
||||
mov [es:di],al ; 0000F294 268805 '&..'
|
||||
xf297: ret ; 0000F297 C3 '.'
|
||||
|
|
@ -12817,21 +12886,23 @@ pattern2:
|
|||
|
||||
xf480: mov al,0x7d ; 0000F480 B07D
|
||||
out 0x84,al ; 0000F482 E684
|
||||
mov si,rombuf1 ; 0000F484 BEE0FF
|
||||
mov si,[cs:si] ; 0000F487 2E8B34 '..4'
|
||||
test word [cs:si],0xf00 ; 0000F48A 2EF704000F '.....'
|
||||
jz xf494 ; 0000F48F 7403 't.'
|
||||
jmp xf684 ; 0000F491 E9F001 '...'
|
||||
mov si,bim_table_offset ; 0000F484 BEE0FF
|
||||
mov si,[cs:si] ; 0000F487 2E8B34
|
||||
test word [cs:si],0x0f00 ; 0000F48A 2EF704000F
|
||||
jz xf494 ; 0000F48F 7403
|
||||
jmp xf684 ; 0000F491 E9F001
|
||||
|
||||
xf494: mov al,0x0 ; 0000F494 B000
|
||||
out 0x80,al ; 0000F496 E680
|
||||
|
||||
xf494: mov al,0x0 ; 0000F494 B000 '..'
|
||||
out 0x80,al ; 0000F496 E680 '..'
|
||||
;;
|
||||
;; TODO: Determine why the ROM uses gdtr_hi instead of gdtr_lo this time.
|
||||
;;
|
||||
;; When we arrive here, the A20 line has been disabled, so in theory, the GDT-in-ROM
|
||||
;; is accessible only at the "lo" ROM address (%0F0730), not the "hi" address (%FF0730).
|
||||
;; Which means the following JMP through selector 0x28 (indeed, any selector access)
|
||||
;; should immediately fail. Yet somehow this code still works?
|
||||
;; should immediately fail. TODO: Determine how this code works in "real life"
|
||||
;;
|
||||
;; It seems this code doesn't really do much PROVIDED bits 6 and 7 of the RAM Settings
|
||||
;; register are set to anything other than 0x40.
|
||||
;;
|
||||
lgdt [cs:0x077e] ; 0000F498 load [gdtr_hi] into GDTR
|
||||
mov eax,cr0 ; 0000F49E 0F2000
|
||||
|
|
@ -12849,9 +12920,13 @@ xf4ac: mov ax,0x8 ; 0000F4AC B80800 '...'
|
|||
xchg ah,al ; 0000F4BC 86E0 '..'
|
||||
out 0x61,al ; 0000F4BE E661 '.a'
|
||||
and ah,0xc0 ; 0000F4C0 80E4C0 '...'
|
||||
cmp ah,0x40 ; 0000F4C3 80FC40 '..@'
|
||||
jz xf4cb ; 0000F4C6 7403 't.'
|
||||
jmp xf655 ; 0000F4C8 E98A01 '...'
|
||||
|
||||
;;
|
||||
;; (AH) contains only bits 6 and 7 from the RAM Settings/Diagnostics register
|
||||
;;
|
||||
cmp ah,0x40 ; 0000F4C3 80FC40
|
||||
jz xf4cb ; 0000F4C6 7403
|
||||
jmp xf655 ; 0000F4C8 E98A01
|
||||
|
||||
xf4cb: or byte [0x2],0x40 ; 0000F4CB 800E020040 '....@'
|
||||
mov ax,0x38 ; 0000F4D0 B83800 '.8.'
|
||||
|
|
@ -13013,6 +13088,7 @@ xf63b: mov ax,0x8 ; 0000F63B B80800 '...'
|
|||
cmp al,0x0 ; 0000F64C 3C00 '<.'
|
||||
jnz xf655 ; 0000F64E 7505 'u.'
|
||||
or byte [0x2],0x40 ; 0000F650 800E020040 '....@'
|
||||
|
||||
xf655: mov ax,0x10 ; 0000F655 B81000 '...'
|
||||
mov es,ax ; 0000F658 8EC0 '..'
|
||||
mov ds,ax ; 0000F65A 8ED8 '..'
|
||||
|
|
@ -13757,16 +13833,31 @@ xffb3: pop ds ; 0000FFB3 1F '.'
|
|||
|
||||
times 29 db 0xFF ; 0000FFC0 - 0000FFDC
|
||||
|
||||
jmp x9f17 ; 0000FFDD E9379F '.7.'
|
||||
jmp x9f17 ; 0000FFDD E9379F
|
||||
|
||||
rombuf1:dw 0x7FB6 ; 0000FFE0 B67F
|
||||
rombuf2:dw 0x7FBE ; 0000FFE2 BE7F
|
||||
;;
|
||||
;; Offset for storing built-in memory table
|
||||
;;
|
||||
;; (Refer to "Compaq Built-in Memory" description at the top of this file)
|
||||
;;
|
||||
bim_table_offset:
|
||||
dw 0x7FB6 ; 0000FFE0 B67F
|
||||
|
||||
db 'G4J 03COMPAQ' ; 0000FFE4 47344A203033434F4D504151
|
||||
;;
|
||||
;; Offset for storing CPU identifier (low byte) and revision number (high byte)
|
||||
;;
|
||||
cpu_idrev_offset:
|
||||
dw 0x7FBE ; 0000FFE2 BE7F
|
||||
|
||||
db 'G' ; 0000FFE4 Product Family Code
|
||||
db '4' ; 0000FFE5 Point-Release Code
|
||||
db 'J ' ; 0000FFE6 Revision Code
|
||||
db '03' ; 0000FFE8 BIOS Type Code
|
||||
db 'COMPAQ' ; 0000FFEA Machine ID
|
||||
|
||||
jmp 0xf000:reset ; 0000FFF0 EA05F900F0
|
||||
|
||||
db 0x20
|
||||
db '01/28/88'
|
||||
db 0xFC ; 0000FFFE FC
|
||||
db 0x98 ; 0000FFFF 98
|
||||
db 0x20 ; 0000FFF5
|
||||
db '01/28/88' ; 0000FFF6 BIOS Revision Date
|
||||
db 0xFC ; 0000FFFE Machine Type Code
|
||||
db 0x98 ; 0000FFFF Checksum
|
||||
|
|
|
|||
Loading…
Reference in a new issue