Stage 10

Makefile

@@ -43,8 +43,10 @@ USER_CC ?= cc
 USER_LD ?= ld
 RUSTC ?= rustc
 USER_LINKER_SCRIPT := cleonos/c/user.ld
+KELF_LINKER_SCRIPT := cleonos/c/kelf.ld
 USER_CFLAGS := -std=c11 -ffreestanding -fno-stack-protector -fno-builtin -Wall -Wextra -Werror -Icleonos/c/include
 USER_LDFLAGS := -nostdlib -z max-page-size=0x1000 -T $(USER_LINKER_SCRIPT)
+KELF_LDFLAGS := -nostdlib -z max-page-size=0x1000 -T $(KELF_LINKER_SCRIPT)
 
 ifeq ($(NO_COLOR),1)
 COLOR_RESET :=
@@ -93,6 +95,7 @@ C_SOURCES := \
     clks/kernel/userland.c \
     clks/kernel/driver.c \
     clks/kernel/service.c \
+    clks/kernel/kelf.c \
     clks/lib/string.c \
     clks/drivers/serial/serial.c \
     clks/drivers/video/framebuffer.c \
@@ -112,11 +115,16 @@ USER_COMMON_SOURCES := \
 
 USER_COMMON_OBJECTS := $(patsubst %.c,$(USER_OBJ_ROOT)/%.o,$(USER_COMMON_SOURCES))
 USER_SHELL_OBJECT := $(USER_OBJ_ROOT)/cleonos/c/apps/shell_main.o
-USER_ELFRUNNER_OBJECT := $(USER_OBJ_ROOT)/cleonos/c/apps/elfrunner_main.o
-USER_MEMC_OBJECT := $(USER_OBJ_ROOT)/cleonos/c/apps/memc_main.o
 USER_TTYDRV_OBJECT := $(USER_OBJ_ROOT)/cleonos/c/apps/ttydrv_main.o
+USER_ELFRUNNER_KOBJ := $(USER_OBJ_ROOT)/cleonos/c/apps/elfrunner_kmain.o
+USER_MEMC_KOBJ := $(USER_OBJ_ROOT)/cleonos/c/apps/memc_kmain.o
 USER_RUST_LIB := $(USER_LIB_DIR)/libcleonos_user_rust.a
-USER_APPS := $(USER_APP_DIR)/shell.elf $(USER_APP_DIR)/elfrunner.elf $(USER_APP_DIR)/memc.elf $(USER_APP_DIR)/ttydrv.elf
+
+APP_SHELL := $(USER_APP_DIR)/shell.elf
+APP_TTYDRV := $(USER_APP_DIR)/ttydrv.elf
+APP_ELFRUNNER := $(USER_APP_DIR)/elfrunner.elf
+APP_MEMC := $(USER_APP_DIR)/memc.elf
+USER_APPS := $(APP_SHELL) $(APP_TTYDRV) $(APP_ELFRUNNER) $(APP_MEMC)
 
 CFLAGS_COMMON := -std=c11 -ffreestanding -fno-stack-protector -fno-builtin -Wall -Wextra -Werror -Iclks/include
 ASFLAGS_COMMON := -ffreestanding -Iclks/include
@@ -206,10 +214,10 @@ ramdisk-root: userapps
 > @mkdir -p $(RAMDISK_ROOT)
 > @cp -a ramdisk/. $(RAMDISK_ROOT)/
 > @mkdir -p $(RAMDISK_ROOT)/system $(RAMDISK_ROOT)/shell $(RAMDISK_ROOT)/driver
-> @cp $(USER_APP_DIR)/shell.elf $(RAMDISK_ROOT)/shell/shell.elf
+> @cp $(APP_SHELL) $(RAMDISK_ROOT)/shell/shell.elf
-> @cp $(USER_APP_DIR)/elfrunner.elf $(RAMDISK_ROOT)/system/elfrunner.elf
+> @cp $(APP_ELFRUNNER) $(RAMDISK_ROOT)/system/elfrunner.elf
-> @cp $(USER_APP_DIR)/memc.elf $(RAMDISK_ROOT)/system/memc.elf
+> @cp $(APP_MEMC) $(RAMDISK_ROOT)/system/memc.elf
-> @cp $(USER_APP_DIR)/ttydrv.elf $(RAMDISK_ROOT)/driver/ttydrv.elf
+> @cp $(APP_TTYDRV) $(RAMDISK_ROOT)/driver/ttydrv.elf
 
 ramdisk: $(RAMDISK_IMAGE)
 
@@ -238,26 +246,26 @@ $(USER_RUST_LIB): cleonos/rust/src/lib.rs Makefile
 > @mkdir -p $(dir $@)
 > @$(RUSTC) --crate-type staticlib -C panic=abort -O $< -o $@
 
-$(USER_APP_DIR)/shell.elf: $(USER_COMMON_OBJECTS) $(USER_SHELL_OBJECT) $(USER_RUST_LIB) $(USER_LINKER_SCRIPT)
+$(APP_SHELL): $(USER_COMMON_OBJECTS) $(USER_SHELL_OBJECT) $(USER_RUST_LIB) $(USER_LINKER_SCRIPT)
 > $(call log_step,linking user shell.elf)
 > @mkdir -p $(dir $@)
 > @$(USER_LD) $(USER_LDFLAGS) -o $@ $(USER_COMMON_OBJECTS) $(USER_SHELL_OBJECT) $(USER_RUST_LIB)
 
-$(USER_APP_DIR)/elfrunner.elf: $(USER_COMMON_OBJECTS) $(USER_ELFRUNNER_OBJECT) $(USER_LINKER_SCRIPT)
+$(APP_TTYDRV): $(USER_COMMON_OBJECTS) $(USER_TTYDRV_OBJECT) $(USER_LINKER_SCRIPT)
-> $(call log_step,linking user elfrunner.elf)
-> @mkdir -p $(dir $@)
-> @$(USER_LD) $(USER_LDFLAGS) -o $@ $(USER_COMMON_OBJECTS) $(USER_ELFRUNNER_OBJECT)
-
-$(USER_APP_DIR)/memc.elf: $(USER_COMMON_OBJECTS) $(USER_MEMC_OBJECT) $(USER_LINKER_SCRIPT)
-> $(call log_step,linking user memc.elf)
-> @mkdir -p $(dir $@)
-> @$(USER_LD) $(USER_LDFLAGS) -o $@ $(USER_COMMON_OBJECTS) $(USER_MEMC_OBJECT)
-
-$(USER_APP_DIR)/ttydrv.elf: $(USER_COMMON_OBJECTS) $(USER_TTYDRV_OBJECT) $(USER_LINKER_SCRIPT)
 > $(call log_step,linking user ttydrv.elf)
 > @mkdir -p $(dir $@)
 > @$(USER_LD) $(USER_LDFLAGS) -o $@ $(USER_COMMON_OBJECTS) $(USER_TTYDRV_OBJECT)
 
+$(APP_ELFRUNNER): $(USER_ELFRUNNER_KOBJ) $(KELF_LINKER_SCRIPT)
+> $(call log_step,linking kernel-elf elfrunner.elf)
+> @mkdir -p $(dir $@)
+> @$(USER_LD) $(KELF_LDFLAGS) -o $@ $(USER_ELFRUNNER_KOBJ)
+
+$(APP_MEMC): $(USER_MEMC_KOBJ) $(KELF_LINKER_SCRIPT)
+> $(call log_step,linking kernel-elf memc.elf)
+> @mkdir -p $(dir $@)
+> @$(USER_LD) $(KELF_LDFLAGS) -o $@ $(USER_MEMC_KOBJ)
+
 $(RAMDISK_IMAGE): ramdisk-root Makefile
 > $(call log_step,packing ramdisk -> $(RAMDISK_IMAGE))
 > @mkdir -p $(dir $@)

cleonos/c/apps/elfrunner_kmain.c

@@ -0,0 +1,8 @@
+typedef unsigned long long u64;
+
+static u64 clks_local_counter = 0ULL;
+
+u64 cleonos_kelf_entry(u64 tick, u64 run_count) {
+    clks_local_counter += (run_count ^ tick) & 0xFFULL;
+    return clks_local_counter;
+}

cleonos/c/apps/memc_kmain.c

@@ -0,0 +1,8 @@
+typedef unsigned long long u64;
+
+static u64 clks_memc_state = 0ULL;
+
+u64 cleonos_kelf_entry(u64 tick, u64 run_count) {
+    clks_memc_state += (tick & 0x1FULL) + run_count;
+    return clks_memc_state;
+}

cleonos/c/include/cleonos_syscall.h

@@ -11,6 +11,8 @@ typedef unsigned long long usize;
 #define CLEONOS_SYSCALL_SERVICE_COUNT       4ULL
 #define CLEONOS_SYSCALL_SERVICE_READY_COUNT 5ULL
 #define CLEONOS_SYSCALL_CONTEXT_SWITCHES    6ULL
+#define CLEONOS_SYSCALL_KELF_COUNT          7ULL
+#define CLEONOS_SYSCALL_KELF_RUNS           8ULL
 
 u64 cleonos_syscall(u64 id, u64 arg0, u64 arg1, u64 arg2);
 u64 cleonos_sys_log_write(const char *message, u64 length);

cleonos/c/kelf.ld

@@ -0,0 +1,29 @@
+OUTPUT_FORMAT(elf64-x86-64)
+ENTRY(cleonos_kelf_entry)
+
+PHDRS {
+    text PT_LOAD FLAGS(5);
+    rodata PT_LOAD FLAGS(4);
+    data PT_LOAD FLAGS(6);
+}
+
+SECTIONS {
+    . = 0x0;
+
+    .text : ALIGN(0x1000) {
+        *(.text .text.*)
+    } :text
+
+    .rodata : ALIGN(0x1000) {
+        *(.rodata .rodata.*)
+    } :rodata
+
+    .data : ALIGN(0x1000) {
+        *(.data .data.*)
+    } :data
+
+    .bss : ALIGN(0x1000) {
+        *(COMMON)
+        *(.bss .bss.*)
+    } :data
+}

clks/include/clks/kelf.h

@@ -0,0 +1,13 @@
+#ifndef CLKS_KELF_H
+#define CLKS_KELF_H
+
+#include <clks/types.h>
+
+typedef u64 (*clks_kelf_entry_fn)(u64 tick, u64 run_count);
+
+void clks_kelf_init(void);
+void clks_kelf_tick(u64 tick);
+u64 clks_kelf_count(void);
+u64 clks_kelf_total_runs(void);
+
+#endif

clks/include/clks/service.h

@@ -11,6 +11,7 @@ enum clks_service_id {
     CLKS_SERVICE_FS = 3,
     CLKS_SERVICE_DRIVER = 4,
     CLKS_SERVICE_SCHED = 5,
+    CLKS_SERVICE_KELF = 6,
 };
 
 enum clks_service_state {

clks/include/clks/syscall.h

@@ -10,6 +10,8 @@
 #define CLKS_SYSCALL_SERVICE_COUNT       4ULL
 #define CLKS_SYSCALL_SERVICE_READY_COUNT 5ULL
 #define CLKS_SYSCALL_CONTEXT_SWITCHES    6ULL
+#define CLKS_SYSCALL_KELF_COUNT          7ULL
+#define CLKS_SYSCALL_KELF_RUNS           8ULL
 
 void clks_syscall_init(void);
 u64 clks_syscall_dispatch(void *frame_ptr);

clks/kernel/kelf.c

@@ -0,0 +1,254 @@
+#include <clks/elf64.h>
+#include <clks/fs.h>
+#include <clks/heap.h>
+#include <clks/kelf.h>
+#include <clks/log.h>
+#include <clks/string.h>
+#include <clks/types.h>
+
+#define CLKS_KELF_MAX_APPS 8U
+#define CLKS_ELF64_PT_LOAD 1U
+
+struct clks_elf64_ehdr {
+    u8 e_ident[16];
+    u16 e_type;
+    u16 e_machine;
+    u32 e_version;
+    u64 e_entry;
+    u64 e_phoff;
+    u64 e_shoff;
+    u32 e_flags;
+    u16 e_ehsize;
+    u16 e_phentsize;
+    u16 e_phnum;
+    u16 e_shentsize;
+    u16 e_shnum;
+    u16 e_shstrndx;
+};
+
+struct clks_elf64_phdr {
+    u32 p_type;
+    u32 p_flags;
+    u64 p_offset;
+    u64 p_vaddr;
+    u64 p_paddr;
+    u64 p_filesz;
+    u64 p_memsz;
+    u64 p_align;
+};
+
+struct clks_kelf_app {
+    clks_bool loaded;
+    char path[64];
+    void *runtime_image;
+    u64 runtime_size;
+    clks_kelf_entry_fn entry;
+    u64 run_count;
+    u64 last_run_tick;
+    u64 last_ret;
+};
+
+static struct clks_kelf_app clks_kelf_apps[CLKS_KELF_MAX_APPS];
+static u64 clks_kelf_app_count = 0ULL;
+static u64 clks_kelf_total_runs_count = 0ULL;
+static u64 clks_kelf_rr_index = 0ULL;
+static u64 clks_kelf_last_dispatch_tick = 0ULL;
+
+static void clks_kelf_copy_name(char *dst, usize dst_size, const char *src) {
+    usize i = 0U;
+
+    if (dst == CLKS_NULL || dst_size == 0U) {
+        return;
+    }
+
+    while (i + 1U < dst_size && src[i] != '\0') {
+        dst[i] = src[i];
+        i++;
+    }
+
+    dst[i] = '\0';
+}
+
+static clks_bool clks_kelf_load_runtime_image(const void *image,
+                                              u64 size,
+                                              void **out_runtime,
+                                              u64 *out_runtime_size,
+                                              clks_kelf_entry_fn *out_entry) {
+    const struct clks_elf64_ehdr *eh;
+    u64 min_vaddr = 0xffffffffffffffffULL;
+    u64 max_vaddr = 0ULL;
+    u16 i;
+    u8 *runtime;
+
+    if (out_runtime == CLKS_NULL || out_runtime_size == CLKS_NULL || out_entry == CLKS_NULL) {
+        return CLKS_FALSE;
+    }
+
+    if (clks_elf64_validate(image, size) == CLKS_FALSE) {
+        return CLKS_FALSE;
+    }
+
+    eh = (const struct clks_elf64_ehdr *)image;
+
+    for (i = 0; i < eh->e_phnum; i++) {
+        const struct clks_elf64_phdr *ph =
+            (const struct clks_elf64_phdr *)((const u8 *)image + eh->e_phoff + ((u64)i * eh->e_phentsize));
+        u64 seg_end;
+
+        if (ph->p_type != CLKS_ELF64_PT_LOAD || ph->p_memsz == 0ULL) {
+            continue;
+        }
+
+        if (ph->p_filesz > ph->p_memsz) {
+            return CLKS_FALSE;
+        }
+
+        if (ph->p_offset > size || ph->p_filesz > (size - ph->p_offset)) {
+            return CLKS_FALSE;
+        }
+
+        seg_end = ph->p_vaddr + ph->p_memsz;
+
+        if (seg_end < ph->p_vaddr) {
+            return CLKS_FALSE;
+        }
+
+        if (ph->p_vaddr < min_vaddr) {
+            min_vaddr = ph->p_vaddr;
+        }
+
+        if (seg_end > max_vaddr) {
+            max_vaddr = seg_end;
+        }
+    }
+
+    if (max_vaddr <= min_vaddr) {
+        return CLKS_FALSE;
+    }
+
+    *out_runtime_size = max_vaddr - min_vaddr;
+    runtime = (u8 *)clks_kmalloc((usize)(*out_runtime_size));
+
+    if (runtime == CLKS_NULL) {
+        return CLKS_FALSE;
+    }
+
+    clks_memset(runtime, 0, (usize)(*out_runtime_size));
+
+    for (i = 0; i < eh->e_phnum; i++) {
+        const struct clks_elf64_phdr *ph =
+            (const struct clks_elf64_phdr *)((const u8 *)image + eh->e_phoff + ((u64)i * eh->e_phentsize));
+
+        if (ph->p_type != CLKS_ELF64_PT_LOAD || ph->p_memsz == 0ULL) {
+            continue;
+        }
+
+        clks_memcpy(runtime + (usize)(ph->p_vaddr - min_vaddr),
+                    (const u8 *)image + ph->p_offset,
+                    (usize)ph->p_filesz);
+    }
+
+    if (eh->e_entry < min_vaddr || eh->e_entry >= max_vaddr) {
+        clks_kfree(runtime);
+        return CLKS_FALSE;
+    }
+
+    *out_entry = (clks_kelf_entry_fn)(void *)(runtime + (usize)(eh->e_entry - min_vaddr));
+    *out_runtime = runtime;
+    return CLKS_TRUE;
+}
+
+static void clks_kelf_probe_path(const char *path) {
+    const void *image;
+    u64 size = 0ULL;
+    void *runtime = CLKS_NULL;
+    u64 runtime_size = 0ULL;
+    clks_kelf_entry_fn entry = CLKS_NULL;
+    struct clks_kelf_app *slot;
+
+    if (clks_kelf_app_count >= CLKS_KELF_MAX_APPS) {
+        return;
+    }
+
+    image = clks_fs_read_all(path, &size);
+
+    if (image == CLKS_NULL || size == 0ULL) {
+        clks_log(CLKS_LOG_WARN, "KELF", "APP FILE NOT FOUND");
+        clks_log(CLKS_LOG_WARN, "KELF", path);
+        return;
+    }
+
+    if (clks_kelf_load_runtime_image(image, size, &runtime, &runtime_size, &entry) == CLKS_FALSE) {
+        clks_log(CLKS_LOG_ERROR, "KELF", "APP LOAD FAILED");
+        clks_log(CLKS_LOG_ERROR, "KELF", path);
+        return;
+    }
+
+    slot = &clks_kelf_apps[clks_kelf_app_count];
+    clks_memset(slot, 0, sizeof(*slot));
+
+    slot->loaded = CLKS_TRUE;
+    clks_kelf_copy_name(slot->path, sizeof(slot->path), path);
+    slot->runtime_image = runtime;
+    slot->runtime_size = runtime_size;
+    slot->entry = entry;
+
+    clks_kelf_app_count++;
+
+    clks_log(CLKS_LOG_INFO, "KELF", "APP READY");
+    clks_log(CLKS_LOG_INFO, "KELF", path);
+    clks_log_hex(CLKS_LOG_INFO, "KELF", "RUNTIME_SIZE", runtime_size);
+}
+
+void clks_kelf_init(void) {
+    clks_memset(clks_kelf_apps, 0, sizeof(clks_kelf_apps));
+    clks_kelf_app_count = 0ULL;
+    clks_kelf_total_runs_count = 0ULL;
+    clks_kelf_rr_index = 0ULL;
+    clks_kelf_last_dispatch_tick = 0ULL;
+
+    clks_kelf_probe_path("/system/elfrunner.elf");
+    clks_kelf_probe_path("/system/memc.elf");
+
+    clks_log(CLKS_LOG_INFO, "KELF", "EXECUTOR ONLINE");
+    clks_log_hex(CLKS_LOG_INFO, "KELF", "APP_COUNT", clks_kelf_app_count);
+}
+
+void clks_kelf_tick(u64 tick) {
+    struct clks_kelf_app *app;
+
+    if (clks_kelf_app_count == 0ULL) {
+        return;
+    }
+
+    if (tick - clks_kelf_last_dispatch_tick < 200ULL) {
+        return;
+    }
+
+    clks_kelf_last_dispatch_tick = tick;
+    app = &clks_kelf_apps[clks_kelf_rr_index % clks_kelf_app_count];
+    clks_kelf_rr_index++;
+
+    if (app->loaded == CLKS_FALSE || app->entry == CLKS_NULL) {
+        return;
+    }
+
+    app->run_count++;
+    app->last_run_tick = tick;
+    app->last_ret = app->entry(tick, app->run_count);
+    clks_kelf_total_runs_count++;
+
+    if ((app->run_count & 0x7ULL) == 1ULL) {
+        clks_log(CLKS_LOG_DEBUG, "KELF", "APP EXECUTED");
+        clks_log(CLKS_LOG_DEBUG, "KELF", app->path);
+        clks_log_hex(CLKS_LOG_DEBUG, "KELF", "RET", app->last_ret);
+    }
+}
+
+u64 clks_kelf_count(void) {
+    return clks_kelf_app_count;
+}
+
+u64 clks_kelf_total_runs(void) {
+    return clks_kelf_total_runs_count;
+}

clks/kernel/kmain.c

@@ -6,6 +6,7 @@
 #include <clks/fs.h>
 #include <clks/heap.h>
 #include <clks/interrupts.h>
+#include <clks/kelf.h>
 #include <clks/kernel.h>
 #include <clks/log.h>
 #include <clks/pmm.h>
@@ -51,6 +52,11 @@ static void clks_task_kworker(u64 tick) {
     phase = (phase + 1U) & 3U;
 }
 
+static void clks_task_kelfd(u64 tick) {
+    clks_service_heartbeat(CLKS_SERVICE_KELF, tick);
+    clks_kelf_tick(tick);
+}
+
 void clks_kernel_main(void) {
     const struct limine_framebuffer *boot_fb;
     const struct limine_memmap_response *boot_memmap;
@@ -76,7 +82,7 @@ void clks_kernel_main(void) {
         clks_tty_init();
     }
 
-    clks_log(CLKS_LOG_INFO, "BOOT", "CLEONOS STAGE9 START");
+    clks_log(CLKS_LOG_INFO, "BOOT", "CLEONOS STAGE10 START");
 
     if (boot_fb == CLKS_NULL) {
         clks_log(CLKS_LOG_WARN, "VIDEO", "NO FRAMEBUFFER FROM LIMINE");
@@ -144,6 +150,7 @@ void clks_kernel_main(void) {
     }
 
     clks_driver_init();
+    clks_kelf_init();
 
     clks_scheduler_init();
 
@@ -155,6 +162,10 @@ void clks_kernel_main(void) {
         clks_log(CLKS_LOG_WARN, "SCHED", "FAILED TO ADD KWORKER TASK");
     }
 
+    if (clks_scheduler_add_kernel_task_ex("kelfd", 5U, clks_task_kelfd) == CLKS_FALSE) {
+        clks_log(CLKS_LOG_WARN, "SCHED", "FAILED TO ADD KELFD TASK");
+    }
+
     sched_stats = clks_scheduler_get_stats();
     clks_log_hex(CLKS_LOG_INFO, "SCHED", "TASK_COUNT", sched_stats.task_count);
 

clks/kernel/service.c

@@ -1,6 +1,7 @@
 #include <clks/driver.h>
 #include <clks/fs.h>
 #include <clks/heap.h>
+#include <clks/kelf.h>
 #include <clks/log.h>
 #include <clks/scheduler.h>
 #include <clks/service.h>
@@ -80,6 +81,9 @@ void clks_service_init(void) {
     clks_service_register(CLKS_SERVICE_SCHED,
                           "scheduler",
                           CLKS_SERVICE_STATE_READY);
+    clks_service_register(CLKS_SERVICE_KELF,
+                          "kelf",
+                          (clks_kelf_count() > 0ULL) ? CLKS_SERVICE_STATE_READY : CLKS_SERVICE_STATE_DEGRADED);
 
     clks_log(CLKS_LOG_INFO, "SRV", "KERNEL SERVICES ONLINE");
     clks_log_hex(CLKS_LOG_INFO, "SRV", "COUNT", clks_service_count());

clks/kernel/syscall.c

@@ -1,4 +1,5 @@
 #include <clks/interrupts.h>
+#include <clks/kelf.h>
 #include <clks/log.h>
 #include <clks/scheduler.h>
 #include <clks/service.h>
@@ -92,6 +93,10 @@ u64 clks_syscall_dispatch(void *frame_ptr) {
             struct clks_scheduler_stats stats = clks_scheduler_get_stats();
             return stats.context_switch_count;
         }
+        case CLKS_SYSCALL_KELF_COUNT:
+            return clks_kelf_count();
+        case CLKS_SYSCALL_KELF_RUNS:
+            return clks_kelf_total_runs();
         default:
             return (u64)-1;
     }

docs/stage10.md

@@ -0,0 +1,39 @@
+# CLeonOS Stage10
+
+## Stage Goal
+- Upgrade ELF execution from "inspect-only" to "scheduler-driven kernel ELF execution".
+- Build `/system/elfrunner.elf` and `/system/memc.elf` as kernel-ELF entry binaries.
+- Add CLKS kernel ELF executor (`kelf`) that loads runtime image and dispatches ELF entry.
+- Add `kelfd` scheduler task to periodically execute loaded kernel ELF apps.
+
+## Acceptance Criteria
+- Kernel boots and prints `CLEONOS STAGE10 START`.
+- KELF framework logs:
+  - `APP READY` for `/system/elfrunner.elf` and `/system/memc.elf`
+  - `EXECUTOR ONLINE`
+  - `APP_COUNT` > 0
+- Service framework includes KELF service and logs updated counts.
+- Scheduler task count increases (idle + klogd + kworker + kelfd).
+- System remains stable in interrupt-enabled idle loop.
+
+## Build Targets
+- `make setup`
+- `make userapps`
+- `make iso`
+- `make run`
+- `make debug`
+
+## QEMU Command
+- `qemu-system-x86_64 -M q35 -m 1024M -cdrom build/CLeonOS-x86_64.iso -serial stdio`
+
+## Common Bugs and Debugging
+- `KELF APP LOAD FAILED`:
+  - Check `/system/*.elf` are built using `cleonos/c/kelf.ld` and are valid ELF64.
+- No `APP READY` logs:
+  - Verify ramdisk staging copied system ELF files into `/system`.
+- `kelfd` task missing:
+  - Confirm `clks_scheduler_add_kernel_task_ex("kelfd", ...)` is present in `kmain`.
+- KELF syscall counters return `-1`:
+  - Ensure syscall IDs for `KELF_COUNT` and `KELF_RUNS` match kernel/user headers.
+- Build errors in Makefile app targets:
+  - Verify `APP_ELFRUNNER`/`APP_MEMC` link with `KELF_LDFLAGS` not `USER_LDFLAGS`.