/*
* Copyright 2008-2011, François Revol, revol@free.fr. All rights reserved.
* Copyright 2004-2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
* Copyright 2005, Ingo Weinhold, bonefish@users.sf.net.
* Copyright 2007, Haiku, Inc. All Rights Reserved.
* Distributed under the terms of the MIT license.
*/
/** This file contains the boot floppy, .PRG and BFS boot block entry points
* for the stage 2 boot loader. All 3 entry points load and relocate the
* loader so that it ends up being at ATARI_ZBEOS_BASE.
* This file is built as PIC so it works wherever it is executed.
* Some arithmetic is thus needed to set variables in the relocated code.
* The loader .PRG file is created from the bootloader by a custom ldscript.
*
* Known load addresses:
* floppy: 0x00a34c (EmuTOS in ARAnyM)
* .prg: 0x03543e (depends on the TOS memory)
* BFS: is set in the MBR code.
*
* The floppy and .PRG code is entered at _bs_entry, which jumps further on
* to skip some fake FAT descriptor.
* It first determines which way it was loaded (floppy boot happens in
* supervisor mode, while .PRG are loaded as user code), and jumps to
* the specific part.
*
* The floppy code comes first as it must be in the first sector,
* and loads the rest of the loader at ATARI_ZBEOS_BASE+0x200,
* sets up the new stack and jumps to _start after setting some variables.
* The end of the floppy code contains a placeholder for a checksum which
* is calculated at build-time by the <build>fixup_tos_floppy_chksum tool.
*
* The .PRG code switches to supervisor mode, copies the whole loader
* which is already in memory to ATARI_ZBEOS_BASE. It then sets up the new
* stack and some variables and jumps to _start.
*
* The BFS code is yet to be fully written.
*/
/*
* references :
* http://ftp.netbsd.org/pub/NetBSD/NetBSD-release-3-0/src/sys/arch/atari/stand/xxboot/fdboot/fdboot.S
*/
#include "atari_memory_map.h"
#include "toscalls.h"
// 1 enabled verbose output
//#define DEBUG 1
#define GLOBAL(x) .globl x
#define FUNCTION(x) .global x
#define DRIVE_RETRIES 3
// when the drive reading fails for some reason, it will
// retry this many times until it will report a failure
#define SECTSIZE 512
//.text
_bs_entry:
/* main entry point, both from the floppy boot and .prg */
bra.s real_entry
//FAT lookalike to avoid nasty things from happening
// http://alive.atari.org/alive10/btmania.php
// MS-DOS values :
// http://support.microsoft.com/kb/75131/en
// http://alumnus.caltech.edu/~pje/dosfiles.html
.ascii "Haiku "
.byte 0xbe, 0x50, 0x38 // id
//LITTLE ENDIAN!
.byte 0x00, 0x02 //BPS
.byte 0x02 //SPC
//.byte 0x00 //???
.byte 0x00, 0x02 //RES - number of reserved sectors
.byte 0x00 //NFATS
.byte 0x00, 0x00 //NDIRS
.byte 0x40, 0x0b //NSECTS
.byte 0xf0 //MEDIA
.byte 0x05, 0x00 //SPF
_fat_spt:
.byte 0x12, 0x00 //SPT
.byte 0x02, 0x00 //NSIDES
.byte 0x00, 0x00 //NHID
// we're done
sNumSectors:
// This location will contain the max length of the boot loader
// as written by the build system in 512 byte blocks and depends
// on the offset of the zipped TAR with the kernel and the boot
// modules will start at offset BOOT_ARCHIVE_IMAGE_OFFSET kB.
.word BOOT_ARCHIVE_IMAGE_OFFSET*2
real_entry:
// save the regs to return safely, like the NetBSD loader does:
// http://ftp.netbsd.org/pub/NetBSD/NetBSD-release-3-0/src/sys/arch/atari/stand/xxboot/fdboot/fdboot.S
movem.l %d1-%d7/%a0-%a6,-(%sp)
//DEBUG: determine load location
// lea _bs_entry(%pc),%a0
// move.l %a0,%d0
// bsr putx
lea str,%a0
bsr puts
// first, determine if .prg (user) or bootsect (super)
// Super(SUP_INQUIRE)
move.l #SUP_INQUIRE,-(%sp)
move.w #0x20,-(%sp)
trap #GEMDOS_TRAP
addq.l #6,%sp
cmp.l #SUP_USER,%d0
bne floppy_start
bra prg_start
/*
* floppy boot support code
*/
floppy_start:
//lea label_floppy,%a0
//bsr puts
bsr load_sectors
tst.w %d0
bne load_failed
floppy_done:
move.b #ATARI_BOOT_DRVAPI_FLOPPY,ATARI_ZBEOS_BASE + gBootDriveAPI - _bs_entry
move.w TOSVAR_bootdev,%d0
// XXX: use uint16 ??
move.b %d0,ATARI_ZBEOS_BASE + gBootDriveID - _bs_entry
move.b #1,ATARI_ZBEOS_BASE + gBootedFromImage - _bs_entry
all_done:
// setup stack
move.l #ATARI_ZBEOS_STACK_END,%sp
// say goodbye to TOS
lea msg_j1,%a0
bsr puts
//bra spin
// say hello to haiku_loader
jmp _start
load_failed:
//bra _exit
spin:
bra spin
_exit: /* */
lea failure_string,%a0
bsr puts
bsr getc
movem.l (%sp)+,%d1-%d7/%a0-%a6
rts
//rts
/** Loads %d2 sectors from floppy disk, starting at head XXX %dh, sector %cx.
* The data is loaded to %a2.
*/
load_sectors:
/*
* %d3: remaining sects
* %d4: sectno
* %d5: trackno
* %d6: sideno
* %d7: sect / track
* %a5: buffer
*
*/
// load the rest
// XXX: the NetBSD loader probes it, but trying to asserts ARAnyM
clr.l %d7
move.b _fat_spt,%d7 // sect/track
//move.w #0,%d7 // sect/track
move.w #0,%d6 // sideno
move.w #0,%d5 // trackno
move.w #1,%d4 // sectno
move.w sNumSectors,%d3 // remainder
move.l #ATARI_ZBEOS_BASE,%a5
read_sectors_loop:
bsr.s read_sect
bne read_sectors_fail
moveq #'.',%d0
bsr putc
subq.w #1,%d3 // remainder--
bne.s read_sectors_next
bsr putcrlf
clr.l %d0
rts
// compute next track/side/sector
read_sectors_next:
add.l #SECTSIZE,%a5
addq.w #1,%d4 // sectno++
cmp.w %d7,%d4 // if (sectno == spt)
bne.s .rs2 // {
addq.w #1,%d6 // sideno++
cmp.w #2,%d6 // if (sideno == 2) {
bne .rs1
clr.w %d6 // sideno = 0
addq.w #1,%d5 // trackno++
bsr putcrlf
.rs1: // }
clr.w %d4 // sectno = 0
.rs2: // }
bra.s read_sectors_loop
read_sectors_fail:
tst.w %d7 // s/t
bne read_sectors_fail2
move.w %d4,%d0
bsr putx
move.w %d4,%d7
clr.w %d4
//add.w #1,
bra.s read_sectors_next
read_sectors_fail2:
moveq #1,%d0
rts
read_sect: /* read 1 sector */
/*
* %d4: sectno
* %d5: trackno
* %d6: sideno
* %d7: remaining count
* %a5: buffer
*
*/
move.w #1,-(%sp)
movem.w %d4-%d6,-(%sp)
move.w TOSVAR_bootdev,-(%sp) // devno
clr.l -(%sp) // filler
move.l %a5,-(%sp)
move.w #8,-(%sp) // floprd
trap #XBIOS_TRAP
add.l #20,%sp
tst.l %d0
rts
floppy_end:
// .org FAILURE_STRING
failure_string:
// .string " Loading failed! Press key to reboot.\r\n"
.string " Loading failed! Press key.\r\n"
// .string "FAIL"
putx:
movem.l %d0-%d2/%a0-%a2,-(%sp)
move.l #8-1,%d2
move.l %d0,%d1
putxloop:
move.l %d1,%d0
lsl.l #4,%d1
rol.l #4,%d0
and.l #0x0f,%d0
cmp.b #9,%d0
ble putx0
add.b #'a'-'0'-10,%d0
putx0:
add.b #'0',%d0
putxdisp:
bsr putc
dbf %d2,putxloop
bsr putcrlf
movem.l (%sp)+,%d0-%d2/%a0-%a2
rts
puts:
.loopt:
move.b (%a0)+,%d0
beq .strout
bsr putc
bra .loopt
.strout:
putcrlf:
move.b #'\r',%d0
bsr putc
move.b #'\n',%d0
bsr putc
rts
/* prints the char in d0.b to the console */
putc:
movem.l %d0-%d2/%a0-%a2,-(%sp)
move.w %d0,-(%sp)
move.w #DEV_CON,-(%sp) // DEV_CON
move.w #3,-(%sp) // Bconout
trap #BIOS_TRAP
add.l #6,%sp
movem.l (%sp)+,%d0-%d2/%a0-%a2
rts
/* waits for a key */
getc:
movem.l %d1-%d2/%a0-%a2,-(%sp)
move.w #DEV_CON,-(%sp) // DEV_CON
move.w #2,-(%sp) // Bconin
trap #BIOS_TRAP
add.l #4,%sp
movem.l (%sp)+,%d1-%d2/%a0-%a2
rts
str:
.string "Haiku!"
//label_prg:
// .string "P" //"RG boot"
//label_floppy:
// .string "F" //"loppy boot"
msg_j1:
.string "Jumping to haiku_loader."
shell_end:
//.fill (0x01fe - shell_end), 1, 0x55
.org 0x01fe
boot_code_checksum:
.word 0xaa55-1 // will be replaced by the one calculated by the build.
// we make sure PCs don't try to execute it.
// this bumps the "start" label to offset 0x0200 as
// expected by the BFS boot loader, and also marks
// this block as valid boot block for the BIOS
//XXX: put bfs_start here
bfs_start:
//FIXME:write BFS code
/*
* \AUTO\HAIKU.PRG and ARAnyM BOOTSTRAP() support code
*/
prg_start:
//lea label_prg,%a0
//bsr puts
// .prg:
// we need to switch to supervisor mode anyway
move.l #SUP_SET,-(%sp)
move.w #0x20,-(%sp)
trap #1
addq.l #6,%sp
move.l %d0,saved_super_stack
// disable interrupts
//or.w #0x0700,%sr
// copy the rest of the prg
// load counter
clr.l %d0
move.w sNumSectors,%d0
sub.w #1,%d0
// load addresses
lea _bs_entry,%a0
move.l #ATARI_ZBEOS_BASE,%a1
nextsect:
move.l #512/4-1,%d1
copysect_loop:
move.l (%a0)+,(%a1)+
dbf %d1,copysect_loop
//bsr putx
dbf %d0,nextsect
super_done:
// XXX: copy the rest !
// XXX: force floppy boot for testing to get the kernel tgz for now
move.b #ATARI_BOOT_DRVAPI_FLOPPY,ATARI_ZBEOS_BASE + gBootDriveAPI - _bs_entry
move.b #0,ATARI_ZBEOS_BASE + gBootDriveID - _bs_entry
move.b #1,ATARI_ZBEOS_BASE + gBootedFromImage - _bs_entry
// all done, go to _start
bra all_done
saved_super_stack:
.long 0
GLOBAL(gBootedFromImage):
.byte 0
GLOBAL(gBootDriveAPI):
.byte ATARI_BOOT_DRVAPI_UNKNOWN
GLOBAL(gBootDriveID):
.byte 0
GLOBAL(gBootPartitionOffset):
.long 0
