[9fans] bootiso.s fixed

[cinap_lenrek@gmx.de]

[-- Attachment #1: Type: text/plain, Size: 509 bytes --]

found it!

the problem was the LBPB() to load byte 0 from the pvd for comparsion.
i loaded it into rBX instead of rBL.  found this out after dumping the
buffer and noticed that the contents where the same on t23 and amd
machine.

it all works now. tested on t23, bochs, and amd machine and its
blazing fast :)

updated the tarballs:

/n/sources/contrib/cinap_lenrek/tuttleboot.tgz
http://9hal.ath.cx/usr/cinap_lenrek/tuttleboot.tgz

attached the file and the diff to this mail...

--
cinap

[-- Attachment #2: Type: text/plain, Size: 8528 bytes --]

#include "x16.h"
#include "mem.h"

/*
 * simple Plan 9 bootblock for ISO9660 that can load a uncompressed a.out kernel
 * image. looks for 386/9pcload. if heres no 386 it searches 9pcload in the root.
 * this is a non floppy emulation el torito bootblock!
 *
 * Diagnostics are:
 *	♥	alive!
 *	?	i/o error, will retry
 *	!	i/o error, giving up
 *	F	bad a.out magic
 *	S	could not find the file
 *
 */

#define DATA32SEL	SELECTOR(1, SELGDT, 0)
#define EXEC32SEL	SELECTOR(2, SELGDT, 0)
#define EXEC16SEL	SELECTOR(3, SELGDT, 0)

#define FARRET \
	BYTE $0xCB
#define SWAPB(r) \
	BYTE $0x0F; BYTE $(0xC8|r)
#define XORAL(i) \
	BYTE $0x34; BYTE $i

/* 2048 byte sectors */
#define SECTSHIFT	0x0B
#define BY2SECT	(1<<SECTSHIFT)

/*
 * Data is kept on the stack, indexed by rBP.
 */
#define Xdap		0x00	/* disc address packet */
#define Xdrive		0x12	/* boot drive, passed by BIOS or MBR */
#define Xentry		0x14	/* a.out entry, text, data*/
#define Xtextsz		0x18
#define Xdatasz	0x1c
#define Xload		0x20	/* load pointer */
#define Xcount		0x24	/* # of sectors to load */
#define Xbuf		0x28
#define Xtotal		(Xbuf+BY2SECT)

/* a.out header offsets */
#define Amagic	0x00
#define Atextsz	0x04
#define Adatasz	0x08
#define Aentry		0x14
#define Aouthdr	0x20

TEXT magic(SB), $0
	/* jmp .+ 0x3E  (_start0x40); nop; nop; nop; nop; nop; nop */
	BYTE $0xEB; BYTE $0x3E; BYTE $0x90; BYTE $0x90
	BYTE $0x90; BYTE $0x90; BYTE $0x90; BYTE $0x90

TEXT bipvd(SB), $0
	LONG $0x00000000
TEXT bibootfile(SB), $0
	LONG $0x00000000
TEXT bibootfilelen(SB), $0
	LONG $0x00000000
TEXT bichecksum(SB), $0
	LONG $0x00000000
TEXT bireserved(SB), $0
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000
	LONG $0x00000000

_start0x40:
	CLI

	/* be carefull! do not trash rDL until we reached start() */
	LWI(magic-Xtotal(SB), rSP)
	MW(rSP, rBP)
	LWI(start(SB), rAX)

_farret16:
	CLR(rCX)
	MTSR(rCX, rDS)
	MTSR(rCX, rES)
	MTSR(rCX, rSS)
	PUSHR(rCX)
	PUSHR(rAX)
	FARRET

TEXT return16(SB), $0
	MFCR(rCR0, rAX)
	XORAL(1)
	MTCR(rAX, rCR0)
	LWI(return16ret(SB), rAX)
	JMP _farret16

TEXT return16ret(SB), $0
	STI
	RET

TEXT start(SB), $0
	STI

	SBPB(rDL, Xdrive)

	/* alive! */
	LWI(0x0E03, rAX)
	BIOSCALL(0x10)

	/* A20! we has to enable itt! */
	LWI(0x2401, rAX)
	BIOSCALL(0x15)

	/* find the primary volume descriptor */
	CLR(rDX)
	LWI(0x0010, rAX)

	LWI(0xFF, rCX)
	CLR(rBX)
_nextpvd:
	CALL16(BIOSread(SB))
	LBPB(Xbuf, rBL)
	CMPI(1, rBX)
	JEQ _pvdfound
	CLR(rBX)
	ADDI(1, rAX)
	ADC(rBX, rDX)
	LOOP _nextpvd

	CALL16(srcherror(SB))

_pvdfound:
	/* load lba and length of root directory */
	LBPW((Xbuf+156+2), rAX)
	LBPW((Xbuf+156+4), rDX)
	LBPW((Xbuf+156+10), rCX)
	LBPW((Xbuf+156+12), rBX)

	CALL16(walk(SB))
	CALL16(srcherror(SB))

TEXT load(SB), $0
	CLR(rCX)
	SBPWI(0xFFFF, Xcount+0)
	SBPWI(0xFFFF, Xcount+2)
	CALL16(BIOSread(SB))

_loop:
	PUSHA
	CALL16(BIOSread(SB))
	CALL16(movehigh(SB))
	POPA
	ADDI(1, rAX)
	ADC(rCX, rDX)
	JMP _loop

TEXT BIOSread(SB), $0

	LWI(5, rDI)			/* retry count (ATAPI ZIPs suck) */

_retry:
	PUSHA
	PUSHS(rDS)
	PUSHS(rES)
	PUSHS(rFS)
	PUSHS(rGS)

	SBPW(rAX, Xdap+8)
	SBPW(rDX, Xdap+10)
	SBPWI(0x0010, Xdap+0)	/* reserved + packet size */
	SBPWI(0x0001, Xdap+2)	/* # of blocks to transfer */
	MW(rBP, rSI)
	ADDI(Xbuf, rSI)
	SBPW(rSI, Xdap+4)		/* transfer buffer :offset */
	MFSR(rSS, rSI)			/* transfer buffer seg: */
	SBPW(rSI, Xdap+6)

	MW(rBP, rSI)			/* Xdap == BP */
	LBPB(Xdrive, rDL)
	LWI(0x4200, rAX)

	BIOSCALL(0x13)
	JCC _readok

_reset:
	LWI((0x0E00+'?'), rAX)
	BIOSCALL(0x10)

	/* reset the drive */
	LBPB(Xdrive, rDL)
	CLR(rAX)
	BIOSCALL(0x13)

	POPS(rGS)
	POPS(rFS)
	POPS(rES)
	POPS(rDS)
	POPA

	DEC(rDI)
	JNE _retry

TEXT ioerror(SB), $0
	LBI('!', rAL)
	JMP _error

TEXT fmterror(SB), $0
	LBI('F', rAL)
	JMP _error

TEXT srcherror(SB), $0
	LBI('S', rAL)
	JMP _error

_error:
	/* print error code */
	LBI(0x0E, rAH)
	BIOSCALL(0x10)

	/* wait for almost any key */
	CLR(rAX)
	BIOSCALL(0x16)

	/* reset */
	LWI(0x0472, rBX)		/* warm-start code address */
	LWI(0x1234, rAX)		/* warm-start code */
	POKEW				/* MOVW	AX, ES:[BX] */
	FARJUMP16(0xFFFF, 0x0000)

_readok:
	POPS(rGS)
	POPS(rFS)
	POPS(rES)
	POPS(rDS)
	POPA

	RET

TEXT walk(SB), $0
	PUSHR(rAX)
	PUSHR(rDX)
	PUSHR(rCX)
	PUSHR(rBX)

	CALL16(BIOSread(SB))
	MW(rBP, rBX)
	ADDI(Xbuf, rBX)
	MW(rBX, rDI)

TEXT walknext(SB), $0
	MW(rDI, rSI)

	MW(rSI, rAX)
	SUB(rBX, rAX)
	CMPI(BY2SECT, rAX)
	JGE _nextsector
	CLR(rCX)
	LXB(0, xSI, rCL)
	ORB(rCL, rCL)
	JEQ _nextsector
	ADD(rCX, rDI)

	PUSHI(walktest(SB))
	RET

_nextsector:
	POPR(rBX)
	POPR(rCX)
	POPR(rDX)
	POPR(rAX)

	OR(rCX, rCX)
	JNE _contwalk
	OR(rBX, rBX)
	JEQ _retwalk
	DEC(rBX)
_contwalk:
	SUBI(BY2SECT, rCX)

	CLR(rDI)
	ADDI(1, rAX)
	ADC(rDI, rDX)
	PUSHI(walk(SB))
_retwalk:
	RET

TEXT walktest(SB), $0
	PUSHA

	LXW(2, xSI, rAX)
	LXW(4, xSI, rDX)
	LXW(10, xSI, rCX)
	LXW(12, xSI, rBX)

	PUSHA
	CLR(rCX)
	LXB(25, xSI, rCL)
	ANDI(2, rCX)
	POPA
	JEQ _notdir

	PUSHA
	LWI(dirname(SB), rDX)
	CALL16(cmpiname(SB))
	POPA
	JNE _skipdir

	ADDI((2*12), rSP)
	PUSHI(walk(SB))
	RET

_notdir:
	PUSHA
	LWI(filename(SB), rDX)
	CALL16(cmpiname(SB))
	POPA
	JNE _skipdir

	CALL16(load(SB))
	/* no return */

_skipdir:
	POPA
	PUSHI(walknext(SB))
	RET

TEXT cmpiname(SB), $0
	CLR(rBX)
	CLR(rAX)

	CLR(rCX)
	LXB(32, xSI, rCL)
	ADDI(33, rSI)
	MW(rDX, rDI)

	PUSHR(rDI)
	PUSHR(rCX)
_lenloop:
	LXB(0, xDI, rAL)
	OR(rAX, rAX)
	JEQ _endlen
	DEC(rCX)
	INC(rDI)
	JMP _lenloop
_endlen:
	OR(rCX, rCX)
	POPR(rCX)
	POPR(rDI)
	JNE _ret

_cmploop:
	LXB(0, xSI, rAL)
	LXB(0, xDI, rBL)
	CMPI('a', rAX)
	JLT _nocasea
	CMPI('z', rAX)
	JGT _nocasea
	ADDI(('A' - 'a'), rAX)
_nocasea:
	CMPI('a', rBX)
	JLT _nocaseb
	CMPI('z', rBX)
	JGT _nocaseb
	ADDI(('A' - 'a'), rBX)
_nocaseb:
	CMP(rAX, rBX)
	JNE _ret
	INC(rSI)
	INC(rDI)
	LOOP _cmploop
	OR(rCX, rCX)
_ret:
	RET

TEXT movehigh(SB), $0
	CLI
	LGDT(tgdtptr(SB))

	MFCR(rCR0, rAX)
	XORAL(1)
	MTCR(rAX, rCR0)

	FARJUMP32(EXEC32SEL, movehigh32(SB))

TEXT movehigh32(SB), $0
	/* upper bits seem to be fucked */
	ANDL $0xFFFF, BP
	ANDL $0xFFFF, SP

	MOVL $DATA32SEL, AX
	MOVW AX, DS
	MOVW AX, ES
	MOVW AX, SS

	MOVL Xload(BP), DI
	MOVL Xcount(BP), BX

	MOVL BP, SI
	ADDL $Xbuf, SI

	CMPL BX, $0
	JEQ _boot
	JGT _movedata

	MOVL Amagic(SI), AX
	CMPL AX, $0xeb010000
	JNE _fmterror

	MOVL Aentry(SI), DI
	SWAPB(rDI)
	ANDL $~0xF0000000, DI
	MOVL DI, Xentry(BP)
	SUBL $Aouthdr, DI

	MOVL Atextsz(SI), BX
	SWAPB(rBX)
	MOVL BX, Xtextsz(BP)

	MOVL Adatasz(SI), CX
	SWAPB(rCX)
	MOVL CX, Xdatasz(BP)

	ADDL CX, BX
	ADDL $(BY2SECT-1), BX
	SHRL $SECTSHIFT, BX

_movedata:
	MOVL $BY2SECT, CX
	REP; MOVSB
	DECL BX

	MOVL DI, Xload(BP)
	MOVL BX, Xcount(BP)

_return:
	/* Move back to 16 bit code segment from protected mode */
	BYTE $0xEA; LONG $return16(SB); WORD $EXEC16SEL

_fmterror:
	/* patch the 16 bit caller pc to point to the error function */
	MOVL $fmterror(SB), AX
	MOVW AX, 0(SP)
	JMP _return

_boot:
	/*
	 * we have to move the data segment to a page aligned
	 * address.
	 */
	MOVL Xentry(BP), SI
	MOVL SI, AX
	ADDL Xtextsz(BP), SI
	MOVL SI, DI
	ADDL $(BY2PG-1), DI
	ANDL $(~(BY2PG-1)), DI
	MOVL Xdatasz(BP), CX
	DECL CX
	ADDL CX, SI
	ADDL CX, DI
	INCL CX
	STD
	REP; MOVSB
	JMP *AX

TEXT	tgdt(SB),$0
         /* null descriptor */
         LONG     $0
         LONG     $0

         /* data segment descriptor for 4 gigabytes (PL 0) */
         LONG     $(0xFFFF)
         LONG     $(SEGG|SEGB|(0xF<<16)|SEGP|SEGPL(0)|SEGDATA|SEGW)

         /* exec segment descriptor for 4 gigabytes (PL 0) */
         LONG     $(0xFFFF)
         LONG     $(SEGG|SEGD|(0xF<<16)|SEGP|SEGPL(0)|SEGEXEC|SEGR)

         /* exec segment descriptor for 4 gigabytes (PL 0) 16-bit */
         LONG     $(0xFFFF)
         LONG     $(SEGG|(0xF<<16)|SEGP|SEGPL(0)|SEGEXEC|SEGR)

TEXT	tgdtptr(SB),$0
         WORD     $(4*8)
         LONG     $tgdt(SB)

TEXT dirname(SB), $0
	BYTE $'3'; BYTE $'8'; BYTE $'6'; BYTE $'\z'

TEXT filename(SB), $0
	BYTE $'9'; BYTE $'p'; BYTE $'c'; BYTE $'l'
	BYTE $'o'; BYTE $'a'; BYTE $'d'; BYTE $'\z'

[-- Attachment #3: Type: text/plain, Size: 1880 bytes --]

/n/dump/2010/0407/usr/cinap_lenrek/code/tuttleboot/sys/src/boot/pc/bootiso.s:120,133 - bootiso.s:120,135
  	CLR(rDX)
  	LWI(0x0010, rAX)

- 	LWI(100, rCX)
+ 	LWI(0xFF, rCX)
+ 	CLR(rBX)
  _nextpvd:
  	CALL16(BIOSread(SB))
- 	LBPB(Xbuf, rBX)
+ 	LBPB(Xbuf, rBL)
  	CMPI(1, rBX)
  	JEQ _pvdfound
+ 	CLR(rBX)
  	ADDI(1, rAX)
- 	ADC(rCX, rDX)
+ 	ADC(rBX, rDX)
  	LOOP _nextpvd

  	CALL16(srcherror(SB))
/n/dump/2010/0407/usr/cinap_lenrek/code/tuttleboot/sys/src/boot/pc/bootiso.s:158,167 - bootiso.s:160,174
  	JMP _loop

  TEXT BIOSread(SB), $0
+
  	LWI(5, rDI)			/* retry count (ATAPI ZIPs suck) */

  _retry:
  	PUSHA
+ 	PUSHS(rDS)
+ 	PUSHS(rES)
+ 	PUSHS(rFS)
+ 	PUSHS(rGS)

  	SBPW(rAX, Xdap+8)
  	SBPW(rDX, Xdap+10)
/n/dump/2010/0407/usr/cinap_lenrek/code/tuttleboot/sys/src/boot/pc/bootiso.s:170,187 - bootiso.s:177,195
  	MW(rBP, rSI)
  	ADDI(Xbuf, rSI)
  	SBPW(rSI, Xdap+4)		/* transfer buffer :offset */
- 	MFSR(rES, rSI)			/* transfer buffer seg: */
+ 	MFSR(rSS, rSI)			/* transfer buffer seg: */
  	SBPW(rSI, Xdap+6)

  	MW(rBP, rSI)			/* Xdap == BP */
  	LBPB(Xdrive, rDL)
- 	LBI(0x42, rAH)
+ 	LWI(0x4200, rAX)
+
  	BIOSCALL(0x13)
- 	JCC _popret
+ 	JCC _readok

  _reset:
  	LWI((0x0E00+'?'), rAX)
- 	BIOSCALL(0x10)
+ 	BIOSCALL(0x10)

  	/* reset the drive */
  	LBPB(Xdrive, rDL)
/n/dump/2010/0407/usr/cinap_lenrek/code/tuttleboot/sys/src/boot/pc/bootiso.s:188,194 - bootiso.s:196,207
  	CLR(rAX)
  	BIOSCALL(0x13)

+ 	POPS(rGS)
+ 	POPS(rFS)
+ 	POPS(rES)
+ 	POPS(rDS)
  	POPA
+
  	DEC(rDI)
  	JNE _retry

/n/dump/2010/0407/usr/cinap_lenrek/code/tuttleboot/sys/src/boot/pc/bootiso.s:219,226 - bootiso.s:232,244
  	POKEW				/* MOVW	AX, ES:[BX] */
  	FARJUMP16(0xFFFF, 0x0000)

- _popret:
+ _readok:
+ 	POPS(rGS)
+ 	POPS(rFS)
+ 	POPS(rES)
+ 	POPS(rDS)
  	POPA
+
  	RET

  TEXT walk(SB), $0