[syslinux] boot... round 2

[Gene Cumm]

systemd Mailing List <systemd-devel at lists.freedesktop.org> would be
the wrong address.

On Mon, Jul 13, 2015 at 5:33 AM, poma <pomidorabelisima at gmail.com> wrote:
> On 03.07.2015 21:35, Gene Cumm wrote:
>> On Jul 3, 2015 1:34 PM, "poma" <pomidorabelisima at gmail.com> wrote:
>>
>>> It works OK as whole, for the current git:
>>
>> Excellent!  This problem is solved.  Now to commit a patch.
>>
>> --Gene
>>
>
> Rather than syslinux-6.03.tar.xz with 75 patches, including this patch of yours - to produce a bootable system,
>
> git snapshot - http://repo.or.cz/w/syslinux.git/snapshot/5186539.tar.gz - i.e. syslinux-5186539.tar.gz
> produces a bootable system even without this patch of yours, *but* not out-of-the-box.
>
> Now comes the interesting part,
> isolinux-debug.bin must be engaged, vulgaris isolinux.bin won't do.

That's quite odd that isolinux-debug.bin alone would solve it.  Now
I've learned Latin for common

> Also using debug facility will break the ISOLINUX bootability:
> sed -i '3 s/#//' mk/devel.mk
> sed -i '4 s/# //' mk/devel.mk
> sed -i '5 s/^/#/' mk/devel.mk
>
>
> No matter what, the EXTLINUX is broken.
>
>
> BIOS in question is the SeaBIOS
> http://code.coreboot.org/p/seabios

Good to note though it's not strictly that BIOS from what I've seen.


On Sun, Jul 12, 2015 at 8:58 AM, Gene Cumm <gene.cumm at gmail.com> wrote:
> On Thu, Jul 9, 2015 at 4:57 PM, William Kennington via Syslinux
> <syslinux at zytor.com> wrote:
>> Still not working with gcc5.2 rc
>
> core/fs/diskio_bios.c:395 contains pm_fs_init() which I believe is the
> first protected-mode code.
>
> void pm_fs_init(com32sys_t *regs)
> {
>     static struct bios_disk_private priv;
>
>     writechr('^');
>     priv.regs = regs;
>     fs_init((const struct fs_ops **)regs->eax.l, (void *)&priv);
> }
>
>
> With the above, I see the caret.
>
> The call to this function in ISOLINUX is in core/isolinux.asm:1163
>
> .common:
>             mov ecx,[Hidden]
>             mov ebx,[Hidden+4]
>                 mov si,[bsHeads]
>         mov di,[bsSecPerTrack]
>         push ax
>         mov al,'$'
>         call writechr
>         pop ax
>         pm_call pm_fs_init
>
>
> With the above, I see the dollar sign then the caret (it also appears
> to need some indentation corrections).
>
> William, the above two simple changes may shed a glimmer of light on
> what's going on.

poma, please try the above code.  If you need it in a proper patch, let me know.

-- 
-Gene