BrokenThorn Entertainment

In the CRT article, you define NULL as follows: #ifdef __cplusplus extern "C" { #endif /* standard NULL declaration */ #define NULL 0 // <- This happens unconditionally! #ifdef __cplusplus } #else /* standard NULL declaration */ #define NULL (void*)0 #endif If I'm not mistaken, you define NULL twice...

Ah, that makes perfect sense! Thanks. The reason why it makes perfect sense is that each entry is exactly 8 bytes long, so there's no point in wasting space by allowing non-multiple of 8 indices. Each index (bit 3-15) is basically a scaled index into the table, I just didn't realise the processor pe...

Hi, I am wondering, in the aforementioned tutorial, why you jmp 0x8:Stage2 . I am interested in the segment offset value, 0x8. I understand you explain that to be the offset in the GDT, but I had a look at the intel manual Vol 3A, Section 3.4.2, that the segment selector is actually a packed 16 bit ...

Ah, I see.

Thanks for the explanation

Hi,

I was looking in the code for this tute, namely the ReadSectors routine, and I was wondering why you always read 1 sector at a time, and loop, instead of passing the amount of sectors directly to AL?

If the series reader demand for this is great enough, we might just skip the vga, and use VBE... What would you like? I don't know, I think if VGA is simpler I'd prefer it as a starting point, especially as it's supported on more platforms. 800x600 resolution is plenty for a start. If you like you ...

In Tutorial 6, I was wondering why the bootloader sets org to 0, instead of 0x7c00, like you did previously? You execute a jmp to main right after it, but won't the code be missed, since the BIOS requires the starting code to be at 0x7c00? org 0 ; we will set regisers later start: jmp main ; jump to...