Displaying 5 results from an estimated 5 matches for "rl_checkpt_overflow".
2011 Mar 21
1
[elflink] diskstart.inc:420: error: Sector 1 overflow by 5 bytes
...$ ; Must be <= 8000h
rl_checkpt_off equ ($-$$)
%ifndef DEPEND
-%if rl_checkpt_off > 3FCh ; Need one pointer in here
-%error "Sector 1 overflow"
-%endif
+ %if rl_checkpt_off > 3F6h ; Need one extent
+ %assign rl_checkpt_overflow rl_checkpt_off - 3F6h
+ %error Sector 1 overflow by rl_checkpt_overflow bytes
+ %endif
%endif
-; Sector pointers
- alignz 4
+;
+; Extent pointers... each extent contains an 8-byte LBA and an 2-byte
+; sector count. In most cases, we will only ever need a handful of
+; extents, bu...
2018 Jan 06
2
Structure of VBR in FAT32?
...r modifies first sector of ldlinux,sys to contain a list of
> all
> > of the other locations of ldlinux.sys
>
> Almost. The blockmap MUST have at least one record in the first
> sector but the subsequent blockmap records may exist later. See
> "SectorPtrs" and "rl_checkpt_overflow". I believe 192 entries are
> currently allocated.
>
I will look at the code to try and get it. All of this basically is, "how
do we bootstrap a program that knows how to read FAT filesystem, when it
itself is on that filesystem and we don't know how to read it yet."
192...
2018 Jan 03
2
Structure of VBR in FAT32?
Gene, thanks for doing "Reply-All". I only get digest, so this keeps me in
the loop. Appreciated.
> which appears to be included in diskstart.inc. I will have to dig in and
> see
> > how this all gets compiled (pointers always appreciated :-) ).
>
> Yes.
>
Is the build process documented? Or am I just going to have to plod through
the makefiles?
> As Ady said,
2018 Jan 06
0
Structure of VBR in FAT32?
...linux,sys to contain a list of
>> > all
>> > of the other locations of ldlinux.sys
>>
>> Almost. The blockmap MUST have at least one record in the first
>> sector but the subsequent blockmap records may exist later. See
>> "SectorPtrs" and "rl_checkpt_overflow". I believe 192 entries are
>> currently allocated.
> I will look at the code to try and get it. All of this basically is, "how do
> we bootstrap a program that knows how to read FAT filesystem, when it itself
> is on that filesystem and we don't know how to read it y...
2018 Jan 05
0
Structure of VBR in FAT32?
...ldlinux.sys
> 4. Installer modifies first sector of ldlinux,sys to contain a list of all
> of the other locations of ldlinux.sys
Almost. The blockmap MUST have at least one record in the first
sector but the subsequent blockmap records may exist later. See
"SectorPtrs" and "rl_checkpt_overflow". I believe 192 entries are
currently allocated.
> 5. Installer puts the first 512 bytes of ldlinux.bin into the boot sector
... by reading the existing VBR, modifying ONLY the bytes allowed for
code, then writing the modified VBR back.
> 6. Installer modifies code in VBR (a specific...