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Set Up the Task State Segment (TSS)

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Language

Compiler

2.0s Limit 256MB

Submit and pass all tests to enable saving to GitHub.

Implementation

Implement TSS setup in C.

Requirements:

Define TSS structure with all relevant fields
Fill ESP0 and SS0 for kernel stack
Implement create_tss_descriptor() for GDT
Implement load_tr() that simulates LTR instruction
Show TSS fields printed
Show GDT TSS descriptor
Implement IO bitmap concept
Show that TSS is required for ring 3 -> ring 0 transitions
Print selector value for TSS
Show TR register loaded

Test:

Show TSS created
Show ESP0 and SS0 set
Show TSS descriptor in GDT
Show TR loaded
Show IO bitmap concept

Why This Matters

Even though Linux abandoned hardware task-switching decades ago, it still keeps exactly one TSS per CPU purely to supply ESP0/SS0 — the kernel stack the CPU auto-loads on any ring-3-to-ring-0 interrupt — which is precisely the field you initialize here. Leaving ESP0 as a stale or zero pointer is a real bug that crashes the very first interrupt taken while running user-mode code, since the CPU has nowhere valid to push the interrupt frame.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0

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