system - Panic, halt, and assertion helpers

Headers: kernel/include/kernel/system.h
Source: kernel/arch/i386/system.c

Low-level CPU control and the PANIC/ASSERT macros. These are the lightweight early-boot / assertion helpers; the fail-safe panic screen Makar drops to on an unrecoverable fault (VGA-text render, Context/Resolve diagnostics, spin-then- reboot) is the kpanic/KPANIC path in debug.

---

Macros

PANIC(msg)

#define PANIC(msg) panic(msg, __FILE__, __LINE__);

Convenience wrapper around panic() that automatically supplies the current source file and line number.

ASSERT(b)

#define ASSERT(b) ((b) ? (void)0 : panic_assert(__FILE__, __LINE__, #b));

Evaluates expression b. If b is false, calls panic_assert() with the file, line, and stringified expression. In non-debug builds the expression is still evaluated (no NDEBUG guard), so do not use it with side effects.

---

Functions

io_wait

void io_wait(void);

Inserts a tiny delay (approximately 400 ns) by executing two dummy jumps. Used when communicating with slow legacy hardware (e.g. ATA/ATAPI, 8259 PIC) where a brief pause is required between consecutive port writes.

halt

void halt(void);

Executes the HLT instruction, stopping the CPU until the next interrupt. Called after an unrecoverable exception or assertion failure to freeze execution. Typically invoked inside an infinite loop so the CPU never returns to the faulting code.

panic

void panic(char *msg, char *file, uint32_t line);

Handles an unrecoverable kernel error. Disables interrupts (CLI), prints a formatted message to the VGA terminal, then spins forever.

Parameter	Description
msg	Human-readable error description.
file	Source file name (typically __FILE__).
line	Source line number (typically __LINE__).

panic_assert

void panic_assert(char *file, uint32_t line, char *desc);

Like panic(), but formats the output as a failed assertion. Called automatically by the ASSERT() macro.

Parameter	Description
file	Source file name.
line	Source line number.
desc	Stringified assertion expression.