Development

[assembler-0]

Summary by CodeRabbit

• New Features

  • Added detailed serial output logging for page fault exceptions, including fault address and register values.
  • Enhanced file system and VFS modules with extensive serial debug output for tracing operations and errors.
  • Improved error handling and feedback during file system mounting and initialization.

• Bug Fixes

  • Fixed memory leaks in FAT12 file system initialization and file reading.
  • Improved string handling and buffer safety in file system operations.
  • Enhanced IDE driver reliability with better timeout handling and reduced lock contention.
  • Fixed memory management in shell commands and argument parsing to prevent leaks.

• Refactor

  • Refactored the text editor to use a linear buffer for content and cursor tracking, removing line and column limits.
  • Updated memory allocation routines and naming for clarity and consistency.
  • Improved page table allocation logic to ensure pages are allocated within identity-mapped memory.

• Documentation

  • Updated comments for virtual memory address ranges to clarify address usage.

• Chores

  • Updated build configuration to require additional external tools and changed QEMU serial output settings.

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

This update introduces serial output logging for page fault exceptions, refactors IDE driver locking and timeouts, adds a hexadecimal serial output function, and improves memory management and debugging in the file system and shell. The editor now uses a linear buffer model. Several function signatures and memory allocation routines are updated for clarity and safety.

Changes

Cohort / File(s)	Change Summary
Interrupt Handler Serial Logging arch/x86_64/interrupts/Interrupts.c	Adds serial output logging for page fault exceptions, including CR2, RIP, RSP, and error code, with support from the Serial interface.
IDE Driver Refactoring drivers/Ide.c, drivers/Ide.h	Increases IDE timeouts, adds busy-wait delays, modifies locking to minimize locked regions, and removes internal function declarations from the header.
Serial Output Enhancements drivers/Serial.c, drivers/Serial.h	Adds SerialWriteHex for 64-bit hex output and updates the header to declare this function and include <stdint.h>.
FAT12 Filesystem Improvements fs/FAT12.c	Makes fat12_initialized global, improves memory management on errors, validates cluster reads, and rewrites file reading to use dynamic buffers.
Filesystem String Safety and Debugging fs/Fs.c, fs/Fs.h	Replaces FastMemcpy with manual string copying for null-termination, adds detailed serial debug output, and changes FsWriteFile's size parameter to size_t.
VFS Debugging and FAT12 Integration fs/VFS.c	Adds serial debug output, validates parameters, and conditionally handles FAT12 based on initialization state.
Kernel Memory and Initialization Refactoring kernel/core/Kernel.c, kernel/memory/KernelHeap.c, kernel/memory/KernelHeap.h, kernel/memory/VMem.c, kernel/memory/VMem.h	Ensures page tables are allocated within identity-mapped memory, renames KernelCallocate to KernelAllocate, updates heap layout comments, and refines page table zeroing logic.
Editor Linear Buffer Redesign kernel/etc/Editor.c	Refactors the editor to use a linear buffer and cursor offset, replacing the previous line-based model, and updates file loading/saving and UI logic.
Shell Memory Management kernel/etc/Shell.c	Switches to dynamic allocation for command arguments and buffers, ensuring proper freeing and error handling throughout command execution.
Build System Updates meson.build	Adds dependencies on qemu-img and mkfs.fat, and changes QEMU serial output handling from debugcon to serial.

Sequence Diagram(s)

sequenceDiagram
    participant CPU
    participant InterruptHandler
    participant Serial
    participant Kernel

    CPU->>InterruptHandler: Page Fault Exception (int 14)
    InterruptHandler->>Serial: SerialWrite("Page fault info: ...")
    InterruptHandler->>Serial: SerialWriteHex(CR2, RIP, RSP, error code)
    InterruptHandler->>Kernel: Existing error printouts and handling

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Estimated code review effort

🎯 4 (Complex) | ⏱️ ~40 minutes

Possibly related PRs

• FCKED #15: Adds general debug print and stack dumps in the InterruptHandler, related to exception handling output but not specific to serial logging for page faults.
• Development #53: Modifies the same InterruptHandler for IDE interrupt handling and EOI signaling, sharing code-level overlap in interrupt logic.
• A lot of fixes #48: Refactors InterruptHandler for structured exception handling and debug output, directly overlapping with page fault handling and output logic.

Poem

A rabbit with code in its paws,
Hops through logs, without a pause.
Serial hex streams in the night,
IDEs spin, buffers tight.
Editors now scroll in a line,
Memory safe and debug fine.
Review these bytes—oh, what a delight!
🐇✨

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📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between a462d10 and a90c784.

📒 Files selected for processing (17)

• arch/x86_64/interrupts/Interrupts.c (2 hunks)
• drivers/Ide.c (4 hunks)
• drivers/Ide.h (0 hunks)
• drivers/Serial.c (1 hunks)
• drivers/Serial.h (1 hunks)
• fs/FAT12.c (5 hunks)
• fs/Fs.c (6 hunks)
• fs/Fs.h (1 hunks)
• fs/VFS.c (5 hunks)
• kernel/core/Kernel.c (5 hunks)
• kernel/etc/Editor.c (1 hunks)
• kernel/etc/Shell.c (11 hunks)
• kernel/memory/KernelHeap.c (1 hunks)
• kernel/memory/KernelHeap.h (1 hunks)
• kernel/memory/VMem.c (2 hunks)
• kernel/memory/VMem.h (1 hunks)
• meson.build (2 hunks)

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