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* checksum should be ok now...

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* also added fake FAT descriptors to avoid crashing TOS, but it doesn't boot yet as floppy.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23525 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
François Revol 2008-01-14 21:59:44 +00:00
parent 9b6eca61e0
commit 005ff05292
2 changed files with 57 additions and 11 deletions
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14
src/system/boot/platform/atari_m68k/fixup_tos_floppy_chksum.c
View File

@ -17,13 +17,17 @@ int main(int argc, char **argv)
perror("read");
return 1;
}
for (sum = 0, i = 0; i < (512-2); i++) {
sum += p[i];
for (sum = 0, i = 0; i < (512-2)/2; i++) {
uint16_t v;
v = *p++ << 8;
v += *p++;
sum += v;
}
sum = 0x1234 - sum;
sum = 0x1234 - sum + 1;
//sum = 0xaa55;
// big endian
p[512-2] = (uint8_t)(sum >> 8);
p[512-1] = (uint8_t)sum;
*p++ = (uint8_t)(sum >> 8);
*p++ = (uint8_t)sum;
//lseek(fd, 0LL, SEEK_SET);
write(fd, &sector[512-2], 2);
return 0;

54
src/system/boot/platform/atari_m68k/shell.S
View File

@ -19,6 +19,14 @@
* the entry function of the embedded ELF part of the loader.
*/
/*
* generate boot floppy:
* cd src/system/boot/platform/atari_m68k/ ; make fixup_tos_floppy_chksum; cd -
* dd if=generated/objects/haiku/m68k/release/system/boot/zbeos of=~/floppy.img bs=512 count=20 conv=notrunc
* src/system/boot/platform/atari_m68k/fixup_tos_floppy_chksum ~/floppy.img
* generate .prg:
* generated.m68k/cross-tools/bin/m68k-unknown-haiku-ld -o haiku.prg -T src/system/boot/platform/atari_m68k/prg.ld generated/objects/haiku/m68k/release/system/boot/boot_loader_atari_m68k
*/
#include "atari_memory_map.h"
#include "toscalls.h"
@ -34,9 +42,36 @@
// retry this many times until it will report a failure
//.text
_bs_entry:
/* main entry point, both from the floppy boot and .prg */
bra real_entry
//bra.s skip_fat_skim
bra.s real_entry
//bra.s _bs_entry
//FAT lookalike to avoid nasty things from happening
// http://alive.atari.org/alive10/btmania.php
.ascii "Haiku0"
.byte 0xbe, 0x50, 0x38 // id
//LE
.byte 0x00, 0x02 //BPS
.byte 0x02 //SPC
//.byte 0x00 //???
.byte 0x00, 0x02 //RES - number of reserved sectors
.byte 0x00//0x02 //NFATS
.byte 0x00/*70*/, 0x00 //NDIRS
.byte 0x00, 0x02 //NSECTS
.byte 0xf8 //MEDIA
.byte 0x05, 0x00 //SPF
.byte 0x09, 0x00 //SPT
.byte 0x02, 0x00 //NSIDES
.byte 0x00, 0x00 //NHID
// we're done
skip_fat_skim:
// lea str,%a0
// bsr puts
// bra skip_fat_skim
//rts
// bra real_entry
sNumSectors:
// this location will contain the length of the boot loader as
@ -47,6 +82,10 @@ sNumSectors:
real_entry:
//Pterm0
//move.w #1,%d0
//trap #1
// first, determine if .prg (user) or bootsect (super)
// Super()
move.l #SUP_INQUIRE,-(%sp)
@ -59,6 +98,9 @@ real_entry:
//bra bootsect_start
rts
floppy_start:
lea str,%a0
bsr puts
bra floppy_start
// no interrupt
and.w #0x0700,%sr
// setup stack
@ -122,7 +164,7 @@ prg_start:
move.l %d0,saved_super_stack
// all done
lea unimpl,%a0
jsr puts
bsr puts
spin:
bra spin
@ -181,12 +223,12 @@ unimpl:
.string "Unimplemented."
shell_end:
.fill 0x01fe - tmp_floppy_end, 1, 0x55
// .org 0x01fe
//.fill (0x01fe - shell_end), 1, 0x55
.org 0x01fe
.word 0xaa55-1 // will be replaced by the one calculated by the build.
// we make sure we 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: actually TOS wants a real checksum here so sum is 0x1234!
tmp_floppy_end: