danwdart / danos

DanOS: A little learning operating system for x86 BIOS

Dan Dart

• nb; they/them
• Mad coder
• Interested in Haskell
• Full website
• Software portfolio

danos's Issues

ivt stuff

https://wiki.osdev.org/Interrupt_Vector_Table

CLI/loading

ls is an app for now

Builtins help?

T type k kernel a app
B bintype m multiboot e elf b binary
lTBNN load NN bit type T bintype B
cTNN call

Elf loading

Copy text segment into appropriate memory
And data segment

Investigate protected mode "segmentation"

Read multiboot or elf header

Create elf to demonstrate it's doable

-fPIC kernels? Programs?

Ata c

Normal gym

Above 640k is usually for io
655360B at 0xa0000

Which is hma

So don't load above 0x9000:ffff
That's why failure!

Prot only above 1M so no fat elfs!

Elf kern default 0x100000 which is 1M! Earliest prot only place.

Need prot ata or different loading or something for this.

Slador mmap int 23:18

Ata protocol

Cli loader

Put characters in command buffer until space then put them in parameter buffer until enter

Push num and parameters onto stack and call a find command function - use strcmp for original command.

Find command searches the fat and calls

Each program pops number and pointer to array and decides whether to process or ignore

Heap allocation for malloc size returns memloc

Free frees ptr and decrements heap ptr

Top of heap in one static ptr

app ideas

Apps
Counter app for binary set bgcolours
Timing button press game
Basic like or forth language
Text editor
Com runner
Emulator for arm or gameboy
Shift ctrl flags with keys