[syslinux] mysteries of memdisk code

[Loginov Alexander]

Hello,

 

I was browsing the code for memdisk (I want to adjust it to my hardware)
and noticed a couple of things that I am struggling to understand.  I
would appreciate if someone could clarify the following mysteries to me:

 

1)       _binary_memdisk_bin_start[], _binary_memdisk_bin_end[] and
_binary_memdisk_bin_size[]; These variables are declared (as extern
const chat in 'setup.c') but never defined in the code. Yet, it seems
that somehow they are initialized with the size and start address of
memdisk. How can it be?

2)       What is driverptr (declared in setup())? It is defined as
driverptr = driverseg  << 16; Why is it shifted by 16-bits?

 

Thanks.

 

Best regards,

Alex