From: Tulio A M Mendes <tadryanom@hotmail.com>
Date: Fri, 13 Feb 2026 11:14:26 +0000 (-0300)
Subject: docs: update README, BUILD_GUIDE, POSIX_ROADMAP, TESTING_PLAN for current state
X-Git-Url: https://projects.tadryanom.me/docs/POSIX_ROADMAP.md?a=commitdiff_plain;h=e427764af646a37c9b7d11c1615731dda791828e;p=AdrOS.git

docs: update README, BUILD_GUIDE, POSIX_ROADMAP, TESTING_PLAN for current state

- README: buddy allocator heap, ICMP ping, IOAPIC level-triggered,
  multi-drive ATA, kernel cmdline, kconsole, NO_SYS=0, 20 smoke tests,
  16-check test battery, ~103K LOC across 255 commits, ~95% POSIX coverage
- BUILD_GUIDE: networking, multi-disk QEMU, root= cmdline param,
  test-battery target, 20 smoke checks
- POSIX_ROADMAP: FAT12/16/32 full RW (was FAT16 RO), ext2 full RW (was
  not implemented), NO_SYS=0 threaded mode, ICMP ping, multi-drive ATA,
  kconsole, buddy allocator, 48 total features (31+17), updated remaining
  work tiers
- TESTING_PLAN: 20 smoke checks, test-battery description, updated
  Makefile targets
---

diff --git a/BUILD_GUIDE.md b/BUILD_GUIDE.md
index b82ee89..a236e18 100644
--- a/BUILD_GUIDE.md
+++ b/BUILD_GUIDE.md
@@ -2,7 +2,7 @@
 
 This guide explains how to build and run AdrOS on your local machine (Linux/WSL).
 
-AdrOS is a Unix-like, POSIX-compatible OS kernel with threads, futex synchronization, networking (TCP/IP + DNS via lwIP), dynamic linking infrastructure, FAT16 filesystem, ASLR, vDSO, zero-copy DMA, a POSIX shell, framebuffer graphics (`/dev/fb0`), raw keyboard input (`/dev/kbd`), uid/gid/euid/egid permission enforcement, and a working DOOM port. See [POSIX_ROADMAP.md](docs/POSIX_ROADMAP.md) for the full compatibility checklist.
+AdrOS is a Unix-like, POSIX-compatible OS kernel with threads, futex synchronization, networking (TCP/IP + DNS + ICMP via lwIP in threaded mode), dynamic linking infrastructure, FAT12/16/32 + ext2 filesystems, ASLR, vDSO, zero-copy DMA, multi-drive ATA, a POSIX shell, framebuffer graphics (`/dev/fb0`), raw keyboard input (`/dev/kbd`), uid/gid/euid/egid permission enforcement, an interactive kernel console, and a working DOOM port. See [POSIX_ROADMAP.md](docs/POSIX_ROADMAP.md) for the full compatibility checklist.
 
 ## 1. Dependencies
 
@@ -55,11 +55,26 @@ make ARCH=x86 run
 ```
 
 Persistent storage note:
-- The x86 QEMU run target attaches a `disk.img` file as an IDE drive (primary master).
+- The x86 QEMU run target attaches a `disk.img` file as an IDE drive (primary master) and enables an E1000 NIC.
 - The kernel mounts two filesystems from this disk:
   - `/persist` — minimal persistence filesystem (e.g. `/persist/counter`)
   - `/disk` — hierarchical inode-based filesystem (diskfs) supporting `mkdir`, `unlink`, `rmdir`, `rename`, `getdents`, etc.
 - If `disk.img` does not exist, it is created automatically by the Makefile.
+- The `root=` kernel parameter can override which device is mounted at `/disk` (e.g. `root=/dev/hdb`).
+
+Multi-disk testing:
+- QEMU supports up to 3 IDE hard drives alongside the CD-ROM boot device:
+  - **hda** (index 0) — Primary Master
+  - **hdb** (index 1) — Primary Slave
+  - **hdd** (index 3) — Secondary Slave (hdc = CD-ROM)
+- The kernel auto-detects all attached ATA drives and logs `[ATA] /dev/hdX detected`.
+
+Kernel command line parameters:
+- `root=/dev/hdX` — mount specified device at `/disk` (auto-detects diskfs/FAT/ext2)
+- `init=/path/to/binary` — override init binary (default: `/bin/init.elf`)
+- `ring3` — enable userspace (ring 3) execution
+- `quiet` — suppress non-critical boot messages
+- `noapic` / `nosmp` — disable APIC / SMP
 
 If you are iterating on kernel changes and want to avoid hanging runs, you can wrap it with a timeout:
 ```bash
@@ -77,7 +92,7 @@ Syscall return convention note:
 
 ### Userland programs
 The following ELF binaries are bundled in the initrd:
-- `/bin/init.elf` — comprehensive smoke test suite (19+ checks)
+- `/bin/init.elf` — comprehensive smoke test suite (20+ checks)
 - `/bin/echo` — argv/envp test
 - `/bin/sh` — POSIX sh-compatible shell with `$PATH` search, pipes, redirects, builtins
 - `/bin/cat`, `/bin/ls`, `/bin/mkdir`, `/bin/rm` — core utilities
@@ -119,8 +134,9 @@ Individual test targets:
 ```bash
 make check        # cppcheck + sparse + gcc -fanalyzer
 make test-host    # 47 host-side unit tests (test_utils + test_security)
-make test         # QEMU smoke test (4 CPUs, 40s timeout, 19 checks)
+make test         # QEMU smoke test (4 CPUs, 90s timeout, 20 checks incl. ICMP ping)
 make test-1cpu    # Single-CPU smoke test (50s timeout)
+make test-battery # Full test battery: multi-disk ATA, VFS mount, ping, diskfs (16 checks)
 make test-gdb     # GDB scripted integrity checks (heap, PMM, VGA)
 ```
 
diff --git a/README.md b/README.md
index 6e005f0..1f8cfbd 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ AdrOS is a Unix-like, POSIX-compatible, multi-architecture operating system deve
 - **PMM** — bitmap allocator with spinlock protection, frame reference counting, and contiguous block allocation
 - **VMM** — PAE recursive page directory, per-process address spaces (PDPT + 4 PDs), TLB flush
 - **Copy-on-Write (CoW) fork** — PTE bit 9 as CoW marker + page fault handler
-- **Kernel heap** — doubly-linked free list with coalescing, dynamic growth up to 64MB
+- **Kernel heap** — 8MB Buddy Allocator (power-of-2 blocks 32B–8MB, circular free lists, buddy coalescing, corruption detection)
 - **Slab allocator** — `slab_cache_t` with free-list-in-place and spinlock
 - **Shared memory** — System V IPC style (`shmget`/`shmat`/`shmdt`/`shmctl`)
 - **`mmap`/`munmap`** — anonymous mappings, shared memory backing, and file-backed (fd) mappings
@@ -87,24 +87,32 @@ AdrOS is a Unix-like, POSIX-compatible, multi-architecture operating system deve
 - Generic `readdir`/`getdents` across all VFS types; symlink following in path resolution
 
 ### Networking
-- **E1000 NIC** — Intel 82540EM driver (MMIO, IRQ via IOAPIC)
-- **lwIP TCP/IP stack** — IPv4, static IP (10.0.2.15 via QEMU user-net)
+- **E1000 NIC** — Intel 82540EM driver (MMIO, IRQ 11 via IOAPIC level-triggered, interrupt-driven RX)
+- **lwIP TCP/IP stack** — NO_SYS=0 threaded mode, IPv4, static IP (10.0.2.15 via QEMU user-net)
 - **Socket API** — `socket`/`bind`/`listen`/`accept`/`connect`/`send`/`recv`/`sendto`/`recvfrom`
-- **Protocols** — TCP (`SOCK_STREAM`) + UDP (`SOCK_DGRAM`)
+- **Protocols** — TCP (`SOCK_STREAM`) + UDP (`SOCK_DGRAM`) + ICMP
+- **ICMP ping** — kernel-level ping test to QEMU gateway (10.0.2.2) during boot
 - **DNS resolver** — lwIP-based with async callback and timeout; kernel `dns_resolve()` wrapper
 
 ### Drivers & Hardware
 - **PCI** — full bus/slot/func enumeration with BAR + IRQ
-- **ATA PIO + DMA** — Bus Master IDE with bounce buffer + zero-copy direct DMA, PRDT, IRQ coordination
-- **LAPIC + IOAPIC** — replaces legacy PIC; ISA IRQ routing
+- **ATA PIO + DMA** — Bus Master IDE with bounce buffer + zero-copy direct DMA, PRDT, IRQ coordination; multi-drive support (4 drives: hda/hdb/hdc/hdd across 2 channels)
+- **LAPIC + IOAPIC** — replaces legacy PIC; ISA edge-triggered + PCI level-triggered IRQ routing
 - **SMP** — 4 CPUs via INIT-SIPI-SIPI, per-CPU data via GS segment
 - **ACPI** — MADT parsing for CPU topology and IOAPIC discovery
 - **VBE framebuffer** — maps LFB, pixel drawing, font rendering; `/dev/fb0` device with `ioctl`/`mmap` for userspace access
 - **UART**, **VGA text**, **PS/2 keyboard**, **PIT timer**, **LAPIC timer**
+- **Kernel console (kconsole)** — interactive debug shell with readline, scrollback, command history
 - **RTC** — CMOS real-time clock driver for wall-clock time (`CLOCK_REALTIME`)
 - **E1000 NIC** — Intel 82540EM Ethernet controller
 - **MTRR** — write-combining support via variable-range MTRR programming
 
+### Boot & Kernel Infrastructure
+- **Kernel command line** — Linux-like parser (`init=`, `root=`, `console=`, `ring3`, `quiet`, `noapic`, `nosmp`); unknown tokens forwarded to init as argv/envp
+- **`/proc/cmdline`** — exposes raw kernel command line to userspace
+- **`root=` parameter** — auto-detect and mount filesystem from specified ATA device at `/disk`
+- **Kernel synchronization** — counting semaphores (`ksem_t`), mutexes (`kmutex_t`), mailboxes (`kmbox_t`) with IRQ-safe signaling
+
 ### Userland
 - **ulibc** — `printf`, `malloc`/`free`/`calloc`/`realloc`, `string.h`, `unistd.h`, `errno.h`, `pthread.h`, `signal.h`, `stdio.h` (buffered I/O with line-buffered stdout, unbuffered stderr, `setvbuf`/`setbuf`, `isatty`), `stdlib.h` (`atof`, `strtol`), `ctype.h`, `sys/mman.h` (`mmap`/`munmap`), `sys/ioctl.h`, `sys/times.h`, `sys/uio.h`, `sys/types.h`, `sys/stat.h`, `time.h` (`nanosleep`/`clock_gettime`), `math.h`, `assert.h`, `fcntl.h`, `strings.h`, `inttypes.h`, `linux/futex.h`, `realpath()`
 - **ELF32 loader** — secure with W^X + ASLR; supports `ET_EXEC` + `ET_DYN` + `PT_INTERP` (dynamic linking)
@@ -140,7 +148,8 @@ AdrOS is a Unix-like, POSIX-compatible, multi-architecture operating system deve
 
 ### Testing
 - **47 host-side unit tests** — `test_utils.c` (28) + `test_security.c` (19)
-- **19 QEMU smoke tests** — 4-CPU, expect-based
+- **20 QEMU smoke tests** — 4-CPU expect-based (includes ICMP ping network test)
+- **16-check test battery** — multi-disk ATA (hda+hdb+hdd), VFS mount, ping, diskfs ops (`make test-battery`)
 - **Static analysis** — cppcheck, sparse, gcc -fanalyzer
 - **GDB scripted checks** — heap/PMM/VGA integrity
 - `make test-all` runs everything
@@ -160,15 +169,16 @@ QEMU debug helpers:
 
 See [POSIX_ROADMAP.md](docs/POSIX_ROADMAP.md) for a detailed checklist.
 
-**All 31 planned POSIX implementation tasks are complete**, plus additional features including the DOOM game port, uid/gid/euid/egid permission enforcement, framebuffer device, raw keyboard device, fd-backed mmap, and kernel stack guard pages. The kernel covers **~93%** of the core POSIX interfaces needed for a practical Unix-like system.
+**All 31 planned POSIX tasks are complete**, plus 10+ additional features: DOOM port, uid/gid/euid/egid, framebuffer, raw keyboard, fd-backed mmap, kernel stack guards, FAT12/16/32 full RW, ext2 full RW, ICMP ping, kernel command line parser. ~103K lines of C/ASM/headers across 255 commits. The kernel covers **~95%** of the core POSIX interfaces needed for a practical Unix-like system.
 
 ### Remaining work for full POSIX compliance
 - **Full `ld.so`** — relocation processing for shared libraries (`dlopen`/`dlsym`)
 - **`getaddrinfo`** / `/etc/hosts` — userland name resolution
 - **`sigqueue`** — queued real-time signals
 - **`setitimer`/`getitimer`** — interval timers
-- **Per-CPU scheduler runqueues** — SMP scalability
+- **Per-CPU scheduler runqueues** — SMP scalability (currently all processes run on BSP)
 - **SMAP** — Supervisor Mode Access Prevention
+- **DHCP client** — currently static IP only
 - **Multi-arch bring-up** — ARM/RISC-V functional kernels
 
 ## Directory Structure
@@ -177,7 +187,7 @@ See [POSIX_ROADMAP.md](docs/POSIX_ROADMAP.md) for a detailed checklist.
 - `src/hal/x86/` — HAL x86 (CPU, keyboard, timer, UART, PCI, ATA PIO/DMA, E1000 NIC, RTC)
 - `src/drivers/` — Device drivers (VBE, initrd, VGA, timer)
 - `src/mm/` — Memory management (PMM, heap, slab, arch-independent VMM wrappers)
-- `src/net/` — Networking (lwIP port, DNS resolver)
+- `src/net/` — Networking (lwIP port, E1000 netif, DNS resolver, ICMP ping test)
 - `include/` — Header files
 - `user/` — Userland programs (`init.c`, `echo.c`, `sh.c`, `cat.c`, `ls.c`, `mkdir.c`, `rm.c`, `ldso.c`)
 - `user/doom/` — DOOM port (doomgeneric engine + AdrOS platform adapter)
diff --git a/docs/POSIX_ROADMAP.md b/docs/POSIX_ROADMAP.md
index 5ce1623..c3156f2 100644
--- a/docs/POSIX_ROADMAP.md
+++ b/docs/POSIX_ROADMAP.md
@@ -131,11 +131,11 @@ Notes:
 | **diskfs** (on-disk) | [x] | Hierarchical inodes; full POSIX ops; symlinks; hard links with `nlink` tracking |
 | **persistfs** | [x] | Minimal persistence at `/persist` |
 | **procfs** | [x] | `/proc/meminfo` + per-process `/proc/[pid]/status`, `/proc/[pid]/maps` |
-| **FAT16** (read-only) | [x] | BPB parsing, FAT chain traversal, root dir finddir, VFS read |
+| **FAT12/16/32** (full RW) | [x] | Unified FAT driver, auto-detection by cluster count (MS spec), 8.3 filenames, subdirs, cluster chain management, all VFS mutation ops (create/write/delete/mkdir/rmdir/rename/truncate) |
+| **ext2** (full RW) | [x] | Superblock + block group descriptors, inode read/write, block/inode bitmaps, direct/indirect/doubly-indirect/triply-indirect block mapping, directory entry add/remove/split, hard links, symlinks (inline), create/write/delete/mkdir/rmdir/rename/truncate/link |
 | Permissions (`uid`/`gid`/`euid`/`egid`/mode) | [x] | `chmod`, `chown` with permission checks; VFS `open()` enforces rwx bits vs process euid/egid and file uid/gid/mode |
 | Hard links | [x] | `diskfs_link()` with shared data blocks and `nlink` tracking |
-| Symbolic links | [x] | `symlink`, `readlink`; followed by VFS lookup |
-| ext2 support | [ ] | |
+| Symbolic links | [x] | `symlink`, `readlink`; followed by VFS lookup | |
 
 ## 7. TTY / PTY
 
@@ -164,7 +164,7 @@ Notes:
 | PMM contiguous block alloc | [x] | `pmm_alloc_blocks(count)` / `pmm_free_blocks()` for multi-page DMA |
 | VMM (x86 PAE paging) | [x] | Higher-half kernel, recursive page directory, PAE mode |
 | Per-process address spaces | [x] | PDPT + 4 PDs per process |
-| Kernel heap (`kmalloc`/`kfree`) | [x] | Dynamic growth up to 64MB |
+| Kernel heap (`kmalloc`/`kfree`) | [x] | 8MB Buddy Allocator (power-of-2 blocks 32B–8MB, circular free lists, buddy coalescing) |
 | Slab allocator | [x] | `slab_cache_t` with free-list-in-place |
 | W^X for user ELFs | [x] | Text segments read-only after load |
 | SMEP | [x] | Enabled in CR4 if CPU supports |
@@ -186,11 +186,11 @@ Notes:
 | PS/2 keyboard | [x] | |
 | PIT timer | [x] | |
 | LAPIC timer | [x] | Calibrated, used when APIC available |
-| ATA PIO (IDE) | [x] | Primary master |
+| ATA PIO (IDE) | [x] | Multi-drive support: 4 drives (hda/hdb/hdc/hdd) across 2 channels |
 | ATA DMA (Bus Master IDE) | [x] | Bounce buffer + zero-copy direct DMA, PRDT, IRQ-coordinated |
 | PCI enumeration | [x] | Full bus/slot/func scan with BAR + IRQ |
 | ACPI (MADT parsing) | [x] | CPU topology + IOAPIC discovery |
-| LAPIC + IOAPIC | [x] | Replaces legacy PIC |
+| LAPIC + IOAPIC | [x] | Replaces legacy PIC; ISA edge-triggered + PCI level-triggered routing |
 | SMP (multi-CPU boot) | [x] | 4 CPUs via INIT-SIPI-SIPI, per-CPU data via GS |
 | CPUID feature detection | [x] | Leaf 0/1/7/extended; SMEP/SMAP detection |
 | VBE framebuffer | [x] | Maps LFB, pixel drawing, font rendering; `/dev/fb0` device with `ioctl`/`mmap` |
@@ -199,14 +199,16 @@ Notes:
 | E1000 NIC (Intel 82540EM) | [x] | MMIO-based, IRQ-driven, lwIP integration |
 | RTC (real-time clock) | [x] | CMOS RTC driver; provides wall-clock time for `CLOCK_REALTIME` |
 | MTRR write-combining | [x] | `mtrr_init`/`mtrr_set_range` for variable-range MTRR programming |
+| Kernel console (kconsole) | [x] | Interactive debug shell with readline, scrollback, command history |
 | Virtio-blk | [ ] | |
 
 ## 10. Networking
 
 | Feature | Status | Notes |
 |---------|--------|-------|
-| E1000 NIC driver | [x] | Intel 82540EM, MMIO, IRQ 11 via IOAPIC |
-| lwIP TCP/IP stack | [x] | NO_SYS=1, IPv4, static IP (10.0.2.15) |
+| E1000 NIC driver | [x] | Intel 82540EM, MMIO, IRQ 11 via IOAPIC (level-triggered, active-low), interrupt-driven RX |
+| lwIP TCP/IP stack | [x] | NO_SYS=0 threaded mode (kernel semaphores/mutexes/mailboxes), IPv4, static IP (10.0.2.15) |
+| ICMP ping test | [x] | Kernel-level ping to QEMU gateway (10.0.2.2) during boot; verified via smoke test |
 | `socket` | [x] | `AF_INET`, `SOCK_STREAM` (TCP), `SOCK_DGRAM` (UDP) |
 | `bind`/`listen`/`accept` | [x] | TCP server support |
 | `connect`/`send`/`recv` | [x] | TCP client support |
@@ -273,7 +275,7 @@ Notes:
 
 ## Implementation Progress
 
-### All 31 planned tasks completed ✅ + 7 additional features
+### All 31 planned tasks completed ✅ + 17 additional features
 
 **High Priority (8/8):**
 1. ~~`raise()` em ulibc~~ ✅
@@ -321,6 +323,15 @@ Notes:
 37. ~~Kernel stack guard pages (0xC8000000 region)~~ ✅
 38. ~~uid/gid/euid/egid with VFS permission enforcement~~ ✅
 39. ~~DOOM port (doomgeneric + AdrOS adapter, 450KB doom.elf)~~ ✅
+40. ~~Buddy Allocator heap (replaced doubly-linked-list heap)~~ ✅
+41. ~~lwIP NO_SYS=0 threaded mode (kernel semaphores/mutexes/mailboxes)~~ ✅
+42. ~~kprintf migration (all uart_print→kprintf, 16KB ring buffer, dmesg)~~ ✅
+43. ~~Unified FAT12/16/32 full RW driver (replaced read-only FAT16)~~ ✅
+44. ~~ext2 filesystem full RW~~ ✅
+45. ~~Kernel command line parser (Linux-like: init=, root=, ring3, quiet, /proc/cmdline)~~ ✅
+46. ~~Multi-drive ATA support (4 drives across 2 channels)~~ ✅
+47. ~~IOAPIC level-triggered routing for PCI interrupts~~ ✅
+48. ~~ICMP ping test (kernel-level, verified in smoke test)~~ ✅
 
 ---
 
@@ -341,19 +352,19 @@ Notes:
 
 | Gap | Impact | Effort |
 |-----|--------|--------|
-| **ext2 filesystem** | No standard on-disk filesystem | Large |
 | **`pipe` capacity** — `F_GETPIPE_SZ`/`F_SETPIPE_SZ` | Fixed-size pipe buffer | Small |
 | **`waitid`** — extended wait | Missing POSIX interface | Small |
 | **`posix_spawn`** — efficient process creation | Missing POSIX interface | Medium |
 | **Virtio-blk driver** | Only ATA PIO/DMA disk access | Medium |
 | **SMAP** — Supervisor Mode Access Prevention | Missing hardware security feature | Small |
+| **DHCP client** | Static IP only (10.0.2.15 via QEMU user-net) | Medium |
+| **E1000 rx_thread scheduling** | RX thread not waking from semaphore during ping; inline poll workaround | Medium |
 
 ### Tier 3 — Multi-arch & long-term
 
 | Gap | Impact | Effort |
 |-----|--------|--------|
 | **Multi-arch bring-up** — ARM/RISC-V functional kernels | x86-only | Very Large |
-| **DHCP client** | Static IP only | Medium |
 | **IPv6** | IPv4-only | Large |
 | **POSIX message queues** (`mq_*`) | Missing IPC mechanism | Medium |
 | **POSIX semaphores** (`sem_*`) | Only futex available | Medium |
diff --git a/docs/TESTING_PLAN.md b/docs/TESTING_PLAN.md
index 26ff034..221058e 100644
--- a/docs/TESTING_PLAN.md
+++ b/docs/TESTING_PLAN.md
@@ -5,7 +5,8 @@
 All four testing layers are **implemented and operational**:
 
 - **Static analysis** (`make check`): cppcheck + sparse + gcc -fanalyzer (59 x86 C files)
-- **QEMU smoke tests** (`make test`): expect-based, 19 checks, 4-CPU SMP, 40s timeout
+- **QEMU smoke tests** (`make test`): expect-based, 20 checks (incl. ICMP ping), 4-CPU SMP, 90s timeout
+- **Test battery** (`make test-battery`): 16 checks across 5 QEMU scenarios — multi-disk ATA, VFS mount, ping, diskfs
 - **Host unit tests** (`make test-host`): 47 tests — `test_utils.c` (28) + `test_security.c` (19)
 - **GDB scripted checks** (`make test-gdb`): heap/PMM/VGA integrity validation
 - **Full suite** (`make test-all`): runs check + test-host + test
@@ -55,6 +56,9 @@ This replaces the manual `grep serial.log` approach with a scripted test that:
 
 **Implementation**: `tests/smoke_test.exp` expect script + `make test` target.
 
+A separate **test battery** (`tests/test_battery.exp`) exercises multi-disk ATA detection,
+VFS mount verification, and ICMP ping across multiple QEMU configurations.
+
 ### Layer 3: QEMU + GDB Scripted Debugging (`make test-gdb`)
 
 **Tools**: QEMU `-s -S` + GDB with Python scripting
@@ -102,9 +106,10 @@ To run manually: boot AdrOS with `-vga std`, then execute `/bin/doom.elf` from t
 ## Makefile Targets
 
 ```makefile
-make check      # cppcheck + sparse + gcc -fanalyzer
-make test        # QEMU + expect automated smoke test
-make test-host   # Host-side unit tests for pure functions
-make test-gdb    # QEMU + GDB scripted checks (optional)
-make test-all    # All of the above
+make check        # cppcheck + sparse + gcc -fanalyzer
+make test         # QEMU + expect automated smoke test (20 checks incl. ICMP ping)
+make test-battery # Full test battery: multi-disk ATA, VFS mount, ping, diskfs (16 checks)
+make test-host    # Host-side unit tests for pure functions
+make test-gdb     # QEMU + GDB scripted checks (optional)
+make test-all     # All of the above
 ```