24 files changed, 430 insertions, 213 deletions

diff --git a/arch/x86/machine/acpi.c b/arch/x86/machine/acpi.c
index 93dc3258..dabc7f34 100644
--- a/arch/x86/machine/acpi.c
+++ b/arch/x86/machine/acpi.c
@@ -22,10 +22,12 @@
 #include <string.h>
 
 #include <kern/init.h>
+#include <kern/intr.h>
 #include <kern/kmem.h>
 #include <kern/log.h>
 #include <kern/macros.h>
 #include <kern/panic.h>
+#include <kern/percpu.h>
 #include <kern/shutdown.h>
 #include <machine/acpi.h>
 #include <machine/biosmem.h>
@@ -661,7 +663,7 @@ acpi_load_fadt(void)
     shutdown_register(&acpi_shutdown_ops, ACPI_SHUTDOWN_PRIORITY);
 }
 
-int __init
+static int __init
 acpi_setup(void)
 {
     struct acpi_rsdp rsdp;
@@ -670,18 +672,39 @@ acpi_setup(void)
     error = acpi_find_rsdp(&rsdp);
 
     if (error) {
-        return error;
+        goto error;
     }
 
     error = acpi_copy_tables(&rsdp);
 
     if (error) {
-        return error;
+        goto error;
     }
 
     acpi_info();
     acpi_load_madt();
     acpi_load_fadt();
     acpi_free_tables();
+
+    return 0;
+
+error:
+    /*
+     * For the sake of simplicity, it has been decided to ignore legacy
+     * specifications such as the multiprocessor specification, and use
+     * ACPI only. If ACPI is unavailable, consider the APIC system to
+     * be missing and fall back to using the legaxy XT-PIC.
+     */
+    pic_setup();
     return 0;
 }
+
+INIT_OP_DEFINE(acpi_setup,
+               INIT_OP_DEP(cpu_setup, true),
+               INIT_OP_DEP(intr_bootstrap, true),
+               INIT_OP_DEP(kmem_setup, true),
+               INIT_OP_DEP(log_setup, true),
+               INIT_OP_DEP(percpu_setup, true),
+               INIT_OP_DEP(shutdown_bootstrap, true),
+               INIT_OP_DEP(trap_setup, true),
+               INIT_OP_DEP(vm_kmem_setup, true));
diff --git a/arch/x86/machine/acpi.h b/arch/x86/machine/acpi.h
index b767b9a2..1f65fd6f 100644
--- a/arch/x86/machine/acpi.h
+++ b/arch/x86/machine/acpi.h
@@ -22,12 +22,14 @@
 #ifndef _X86_ACPI_H
 #define _X86_ACPI_H
 
+#include <kern/init.h>
+
 /*
- * Load ACPI information.
- *
- * Return 0 if successful (an error usually means hardware doesn't support
- * ACPI).
+ * This init operation provides :
+ *  - Multiprocessor probing
+ *  - registration of I/O APIC interrupt controllers
+ *  - registration of ACPI shutdown operations
  */
-int acpi_setup(void);
+INIT_OP_DECLARE(acpi_setup);
 
 #endif /* _X86_ACPI_H */
diff --git a/arch/x86/machine/atcons.c b/arch/x86/machine/atcons.c
index e1e14c62..0c35266f 100644
--- a/arch/x86/machine/atcons.c
+++ b/arch/x86/machine/atcons.c
@@ -129,21 +129,28 @@ static const struct console_ops atcons_ops = {
     .putc = atcons_putc,
 };
 
-void __init
+static int __init
 atcons_bootstrap(void)
 {
-    cga_setup();
-
     console_init(&atcons_console, "atcons", &atcons_ops);
     console_register(&atcons_console);
+    return 0;
 }
 
-void __init
+INIT_OP_DEFINE(atcons_bootstrap,
+               INIT_OP_DEP(cga_setup, true),
+               INIT_OP_DEP(console_bootstrap, true));
+
+static int __init
 atcons_setup(void)
 {
-    atkbd_setup();
+    return 0;
 }
 
+INIT_OP_DEFINE(atcons_setup,
+               INIT_OP_DEP(atcons_bootstrap, true),
+               INIT_OP_DEP(atkbd_setup, true));
+
 void
 atcons_intr(const char *s)
 {
diff --git a/arch/x86/machine/atcons.h b/arch/x86/machine/atcons.h
index d6923df2..0d4893a6 100644
--- a/arch/x86/machine/atcons.h
+++ b/arch/x86/machine/atcons.h
@@ -21,17 +21,7 @@
 #ifndef _X86_ATCONS_H
 #define _X86_ATCONS_H
 
-/*
- * Early initialization of the atcons module.
- */
-void atcons_bootstrap(void);
-
-/*
- * Initialize the atcons module.
- *
- * This function enables keyboard interrupt handling.
- */
-void atcons_setup(void);
+#include <kern/init.h>
 
 /*
  * Console interrupt handler.
@@ -49,4 +39,17 @@ void atcons_bottom(void);
 void atcons_right(void);
 void atcons_up(void);
 
+/*
+ * This init operation provides :
+ *  - CGA output through the console module
+ */
+INIT_OP_DECLARE(atcons_bootstrap);
+
+/*
+ * This init operation provides :
+ *  - AT keyboard input through the console module
+ *  - module fully initialized
+ */
+INIT_OP_DECLARE(atcons_setup);
+
 #endif /* _X86_ATCONS_H */
diff --git a/arch/x86/machine/atkbd.c b/arch/x86/machine/atkbd.c
index fd804269..59f8d681 100644
--- a/arch/x86/machine/atkbd.c
+++ b/arch/x86/machine/atkbd.c
@@ -843,7 +843,7 @@ atkbd_intr(void *arg)
     return 0;
 }
 
-void __init
+static int __init
 atkbd_setup(void)
 {
     int error;
@@ -851,25 +851,31 @@ atkbd_setup(void)
     error = atkbd_flush();
 
     if (error) {
-        return;
+        return 0;
     }
 
     error = atkbd_disable();
 
     if (error) {
-        return;
+        return 0;
     }
 
     error = intr_register(ATKBD_INTR1, atkbd_intr, NULL);
 
     if (error) {
         log_err("atkbd: unable to register interrupt handler");
-        return;
+        return 0;
     }
 
     error = atkbd_enable();
 
     if (error) {
-        return;
+        return 0;
     }
+
+    return 0;
 }
+
+INIT_OP_DEFINE(atkbd_setup,
+               INIT_OP_DEP(atcons_bootstrap, true),
+               INIT_OP_DEP(intr_setup, true));
diff --git a/arch/x86/machine/atkbd.h b/arch/x86/machine/atkbd.h
index 0bed7ada..9efeefbf 100644
--- a/arch/x86/machine/atkbd.h
+++ b/arch/x86/machine/atkbd.h
@@ -21,9 +21,12 @@
 #ifndef _X86_ATKBD_H
 #define _X86_ATKBD_H
 
+#include <kern/init.h>
+
 /*
- * Initialize the atkbd module.
+ * This init operation provides :
+ *  - module fully initialized
  */
-void atkbd_setup(void);
+INIT_OP_DECLARE(atkbd_setup);
 
 #endif /* _X86_ATKBD_H */
diff --git a/arch/x86/machine/biosmem.c b/arch/x86/machine/biosmem.c
index 64482c60..fc03614c 100644
--- a/arch/x86/machine/biosmem.c
+++ b/arch/x86/machine/biosmem.c
@@ -33,7 +33,6 @@
 #include <machine/pmap.h>
 #include <machine/pmem.h>
 #include <machine/types.h>
-#include <vm/vm_kmem.h>
 #include <vm/vm_page.h>
 
 #define BIOSMEM_MAX_BOOT_DATA 64
@@ -234,9 +233,9 @@ biosmem_unregister_boot_data(phys_addr_t start, phys_addr_t end)
 
     biosmem_nr_boot_data--;
 
-    boot_memmove(&biosmem_boot_data_array[i],
-                 &biosmem_boot_data_array[i + 1],
-                 (biosmem_nr_boot_data - i) * sizeof(*biosmem_boot_data_array));
+    memmove(&biosmem_boot_data_array[i],
+            &biosmem_boot_data_array[i + 1],
+            (biosmem_nr_boot_data - i) * sizeof(*biosmem_boot_data_array));
 }
 
 static void __boot
@@ -813,7 +812,7 @@ biosmem_load_zone(struct biosmem_zone *zone, uint64_t max_phys_end)
     if (phys_end > max_phys_end) {
         if (max_phys_end <= phys_start) {
             log_warning("biosmem: zone %s physically unreachable, "
-                   "not loaded", vm_page_zone_name(zone_index));
+                        "not loaded", vm_page_zone_name(zone_index));
             return;
         }
 
@@ -847,7 +846,7 @@ biosmem_load_zone(struct biosmem_zone *zone, uint64_t max_phys_end)
     }
 }
 
-void __init
+static int __init
 biosmem_setup(void)
 {
     uint64_t max_phys_end;
@@ -870,8 +869,14 @@ biosmem_setup(void)
         zone = &biosmem_zones[i];
         biosmem_load_zone(zone, max_phys_end);
     }
+
+    return 0;
 }
 
+INIT_OP_DEFINE(biosmem_setup,
+               INIT_OP_DEP(cpu_setup, true),
+               INIT_OP_DEP(log_setup, true));
+
 static void __init
 biosmem_unregister_temporary_boot_data(void)
 {
@@ -925,7 +930,7 @@ biosmem_free_usable_entry(phys_addr_t start, phys_addr_t end)
     }
 }
 
-void __init
+static int __init
 biosmem_free_usable(void)
 {
     struct biosmem_map_entry *entry;
@@ -963,4 +968,12 @@ biosmem_free_usable(void)
 
         biosmem_free_usable_entry(start, end);
     }
+
+    return 0;
 }
+
+INIT_OP_DEFINE(biosmem_free_usable,
+               INIT_OP_DEP(boot_save_data, true),
+               INIT_OP_DEP(panic_setup, true),
+               INIT_OP_DEP(log_setup, true),
+               INIT_OP_DEP(vm_page_setup, true));
diff --git a/arch/x86/machine/biosmem.h b/arch/x86/machine/biosmem.h
index d877af4c..2a701dec 100644
--- a/arch/x86/machine/biosmem.h
+++ b/arch/x86/machine/biosmem.h
@@ -20,6 +20,7 @@
 
 #include <stdbool.h>
 
+#include <kern/init.h>
 #include <machine/multiboot.h>
 #include <machine/types.h>
 
@@ -53,9 +54,9 @@
  * Once all boot data have been registered, the user can set up the
  * early page allocator.
  *
- * If the range is marked temporary, it will be unregistered when
- * biosmem_free_usable() is called, so that pages that used to store
- * these boot data may be released to the VM system.
+ * If the range is marked temporary, it will be unregistered once
+ * the boot data have been saved/consumed so that their backing
+ * pages are loaded into the VM system.
  *
  * This function is called before paging is enabled.
  */
@@ -102,17 +103,9 @@ const void * biosmem_get_bda(void);
 phys_addr_t biosmem_directmap_end(void);
 
 /*
- * Set up physical memory based on the information obtained during bootstrap
- * and load it in the VM system.
+ * This init operation provides :
+ *  - heaps of physical memory are loaded by the VM system
  */
-void biosmem_setup(void);
-
-/*
- * Free all usable memory.
- *
- * This function releases all pages that aren't used by boot data and have
- * not already been loaded into the VM system.
- */
-void biosmem_free_usable(void);
+INIT_OP_DECLARE(biosmem_setup);
 
 #endif /* _X86_BIOSMEM_H */
diff --git a/arch/x86/machine/boot.c b/arch/x86/machine/boot.c
index 571b04f6..25e92ff6 100644
--- a/arch/x86/machine/boot.c
+++ b/arch/x86/machine/boot.c
@@ -43,27 +43,19 @@
  */
 
 #include <stdalign.h>
-#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
 
 #include <kern/arg.h>
-#include <kern/console.h>
 #include <kern/init.h>
-#include <kern/intr.h>
 #include <kern/kmem.h>
 #include <kern/kernel.h>
 #include <kern/log.h>
 #include <kern/macros.h>
 #include <kern/panic.h>
-#include <kern/percpu.h>
-#include <kern/shutdown.h>
-#include <kern/sleepq.h>
-#include <kern/sref.h>
-#include <kern/syscnt.h>
 #include <kern/thread.h>
-#include <kern/turnstile.h>
+#include <machine/acpi.h>
 #include <machine/atcons.h>
 #include <machine/biosmem.h>
 #include <machine/boot.h>
@@ -74,10 +66,8 @@
 #include <machine/page.h>
 #include <machine/pmap.h>
 #include <machine/strace.h>
-#include <machine/trap.h>
 #include <machine/uart.h>
 #include <vm/vm_kmem.h>
-#include <vm/vm_setup.h>
 
 alignas(CPU_DATA_ALIGN) char boot_stack[BOOT_STACK_SIZE] __bootdata;
 alignas(CPU_DATA_ALIGN) char boot_ap_stack[BOOT_STACK_SIZE] __bootdata;
@@ -358,8 +348,8 @@ boot_setup_paging(struct multiboot_raw_info *mbi, unsigned long eax)
     return pmap_setup_paging();
 }
 
-static void __init
-boot_log_version(void)
+void __init
+boot_log_info(void)
 {
     log_info(KERNEL_NAME "/" QUOTE(X15_X86_MACHINE) " " KERNEL_VERSION
 #ifdef X15_X86_PAE
@@ -480,46 +470,24 @@ boot_save_mods(void)
  * the boot loader. Once the boot data are managed as kernel buffers, their
  * backing pages can be freed.
  */
-static void __init
+static int __init
 boot_save_data(void)
 {
     boot_mbi.flags = boot_raw_mbi.flags;
     boot_save_mods();
-    strace_setup(&boot_raw_mbi);
+    return 0;
 }
 
+INIT_OP_DEFINE(boot_save_data,
+               INIT_OP_DEP(kmem_setup, true),
+               INIT_OP_DEP(panic_setup, true),
+               INIT_OP_DEP(vm_kmem_setup, true));
+
 void __init
 boot_main(void)
 {
-    log_setup();
-    arg_setup(boot_tmp_cmdline);
-    sleepq_bootstrap();
-    turnstile_bootstrap();
-    syscnt_setup();
-    percpu_bootstrap();
-    trap_setup();
-    cpu_setup();
-    thread_bootstrap();
-    boot_log_version();
-    arg_log_info();
-    console_setup();
-    atcons_bootstrap();
-    uart_bootstrap();
-    printf_setup();
-    uart_info();
-    pmap_bootstrap();
-    sref_bootstrap();
-    cpu_check(cpu_current());
-    cpu_info(cpu_current());
-    biosmem_setup();
-    vm_setup();
-    boot_save_data();
-    biosmem_free_usable();
-    shutdown_setup();
-    intr_setup();
-    cpu_mp_probe();
-    atcons_setup();
-    uart_setup();
+    arg_set_cmdline(boot_tmp_cmdline);
+    strace_set_mbi(&boot_raw_mbi);
     kernel_main();
 
     /* Never reached */
@@ -529,9 +497,61 @@ void __init
 boot_ap_main(void)
 {
     cpu_ap_setup();
-    thread_ap_bootstrap();
-    pmap_ap_bootstrap();
+    thread_ap_setup();
+    pmap_ap_setup();
     kernel_ap_main();
 
     /* Never reached */
 }
+
+/*
+ * Init operation aliases.
+ */
+
+static int __init
+boot_bootstrap_console(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(boot_bootstrap_console,
+               INIT_OP_DEP(atcons_bootstrap, true),
+               INIT_OP_DEP(uart_bootstrap, true));
+
+static int __init
+boot_setup_console(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(boot_setup_console,
+               INIT_OP_DEP(atcons_setup, true),
+               INIT_OP_DEP(uart_setup, true));
+
+static int __init
+boot_load_vm_page_zones(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(boot_load_vm_page_zones,
+               INIT_OP_DEP(biosmem_setup, true));
+
+static int __init
+boot_setup_intr(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(boot_setup_intr,
+               INIT_OP_DEP(acpi_setup, true));
+
+static int __init
+boot_setup_shutdown(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(boot_setup_shutdown,
+               INIT_OP_DEP(acpi_setup, true),
+               INIT_OP_DEP(cpu_setup_shutdown, true));
diff --git a/arch/x86/machine/boot.h b/arch/x86/machine/boot.h
index 8c590c64..c85c2648 100644
--- a/arch/x86/machine/boot.h
+++ b/arch/x86/machine/boot.h
@@ -60,6 +60,7 @@
 
 #ifndef __ASSEMBLER__
 
+#include <kern/init.h>
 #include <machine/multiboot.h>
 #include <machine/pmap.h>
 
@@ -122,6 +123,47 @@ void boot_main(void);
  */
 void boot_ap_main(void);
 
+/*
+ * Log kernel version and other architecture-specific information.
+ */
+void boot_log_info(void);
+
+/*
+ * This init operation provides :
+ *  - boot data are saved
+ */
+INIT_OP_DECLARE(boot_save_data);
+
+/*
+ * This init operation provides :
+ *  - all console devices are bootstrapped
+ */
+INIT_OP_DECLARE(boot_bootstrap_console);
+
+/*
+ * This init operation provides :
+ *  - all console devices are fully initialized
+ */
+INIT_OP_DECLARE(boot_setup_console);
+
+/*
+ * This init operation provides :
+ *  - physical memory has been loaded to the VM system
+ */
+INIT_OP_DECLARE(boot_load_vm_page_zones);
+
+/*
+ * This init operation provides :
+ *  - all interrupt controllers have been registered
+ */
+INIT_OP_DECLARE(boot_setup_intr);
+
+/*
+ * This init operation provides :
+ *  - all shutdown operations have been registered
+ */
+INIT_OP_DECLARE(boot_setup_shutdown);
+
 #endif /* __ASSEMBLER__ */
 
 #endif /* _X86_BOOT_H */
diff --git a/arch/x86/machine/cga.c b/arch/x86/machine/cga.c
index 3ce4032c..b519ba1f 100644
--- a/arch/x86/machine/cga.c
+++ b/arch/x86/machine/cga.c
@@ -20,10 +20,10 @@
 #include <stdint.h>
 #include <string.h>
 
+#include <kern/console.h>
 #include <kern/error.h>
 #include <kern/init.h>
 #include <kern/cbuf.h>
-#include <kern/console.h>
 #include <kern/macros.h>
 #include <machine/io.h>
 #include <machine/cga.h>
@@ -448,15 +448,17 @@ cga_setup_misc_out(void)
     }
 }
 
-void __init
+static int __init
 cga_setup(void)
 {
     cga_memory = (void *)vm_page_direct_va(CGA_MEMORY);
-
     cga_setup_misc_out();
     cga_bbuf_init(&cga_bbuf, cga_get_cursor_position());
+    return 0;
 }
 
+INIT_OP_DEFINE(cga_setup);
+
 void
 cga_cursor_left(void)
 {
diff --git a/arch/x86/machine/cga.h b/arch/x86/machine/cga.h
index 2310bc91..2708ec4d 100644
--- a/arch/x86/machine/cga.h
+++ b/arch/x86/machine/cga.h
@@ -21,10 +21,7 @@
 #ifndef _X86_CGA_H
 #define _X86_CGA_H
 
-/*
- * Initialize the cga module.
- */
-void cga_setup(void);
+#include <kern/init.h>
 
 /*
  * Append a character to the CGA screen.
@@ -37,4 +34,10 @@ void cga_putc(char c);
 void cga_cursor_left(void);
 void cga_cursor_right(void);
 
+/*
+ * This init operation provides :
+ *  - module fully initialized
+ */
+INIT_OP_DECLARE(cga_setup);
+
 #endif /* _X86_CGA_H */
diff --git a/arch/x86/machine/cpu.c b/arch/x86/machine/cpu.c
index debacf0c..98d3680e 100644
--- a/arch/x86/machine/cpu.c
+++ b/arch/x86/machine/cpu.c
@@ -124,7 +124,7 @@ struct cpu cpu_desc __percpu;
 /*
  * Number of active processors.
  */
-unsigned int cpu_nr_active __read_mostly;
+unsigned int cpu_nr_active __read_mostly = 1;
 
 /*
  * Processor frequency, assumed fixed and equal on all processors.
@@ -557,7 +557,7 @@ cpu_measure_freq(void)
     cpu_freq = (end - start) / (1000000 / CPU_FREQ_CAL_DELAY);
 }
 
-void __init
+static int __init
 cpu_setup(void)
 {
     struct cpu *cpu;
@@ -566,18 +566,23 @@ cpu_setup(void)
     cpu_preinit(cpu, 0, CPU_INVALID_APIC_ID);
     cpu->double_fault_stack = cpu_double_fault_stack; /* XXX */
     cpu_init(cpu);
-    cpu_nr_active = 1;
 
     cpu_measure_freq();
+
+    return 0;
 }
 
+INIT_OP_DEFINE(cpu_setup,
+               INIT_OP_DEP(percpu_bootstrap, true),
+               INIT_OP_DEP(trap_setup, true));
+
 static void __init
 cpu_panic_on_missing_feature(const char *feature)
 {
     panic("cpu: %s feature missing", feature);
 }
 
-void __init
+static void __init
 cpu_check(const struct cpu *cpu)
 {
     if (!(cpu->features2 & CPU_FEATURE2_FPU)) {
@@ -597,8 +602,19 @@ cpu_check(const struct cpu *cpu)
 #endif
 }
 
+static int __init
+cpu_check_bsp(void)
+{
+    cpu_check(cpu_current());
+    return 0;
+}
+
+INIT_OP_DEFINE(cpu_check_bsp,
+               INIT_OP_DEP(cpu_setup, true),
+               INIT_OP_DEP(panic_setup, true));
+
 void
-cpu_info(const struct cpu *cpu)
+cpu_log_info(const struct cpu *cpu)
 {
     log_info("cpu%u: %s, type %u, family %u, model %u, stepping %u",
              cpu->id, cpu->vendor_id, cpu->type, cpu->family, cpu->model,
@@ -657,30 +673,32 @@ static struct shutdown_ops cpu_shutdown_ops = {
     .reset = cpu_shutdown_reset,
 };
 
-void __init
+static int __init
 cpu_mp_probe(void)
 {
-    int error;
-
-    error = acpi_setup();
-
-    if (error) {
-        /*
-         * For the sake of simplicity, it has been decided to ignore legacy
-         * specifications such as the multiprocessor specification, and use
-         * ACPI only. If ACPI is unavailable, consider the APIC system to
-         * be missing and fall back to using the legaxy XT-PIC.
-         */
-        pic_setup();
-    }
-
     log_info("cpu: %u processor(s) configured", cpu_count());
+    return 0;
+}
+
+INIT_OP_DEFINE(cpu_mp_probe,
+               INIT_OP_DEP(acpi_setup, true),
+               INIT_OP_DEP(cpu_setup, true),
+               INIT_OP_DEP(log_setup, true));
 
+static int __init
+cpu_setup_shutdown(void)
+{
     if (cpu_count() == 1) {
         shutdown_register(&cpu_shutdown_ops, CPU_SHUTDOWN_PRIORITY);
     }
+
+    return 0;
 }
 
+INIT_OP_DEFINE(cpu_setup_shutdown,
+               INIT_OP_DEP(cpu_mp_probe, true),
+               INIT_OP_DEP(shutdown_bootstrap, true));
+
 void __init
 cpu_mp_setup(void)
 {
diff --git a/arch/x86/machine/cpu.h b/arch/x86/machine/cpu.h
index ee4eb18b..39f17f84 100644
--- a/arch/x86/machine/cpu.h
+++ b/arch/x86/machine/cpu.h
@@ -127,6 +127,7 @@
 #include <stdint.h>
 #include <stdnoreturn.h>
 
+#include <kern/init.h>
 #include <kern/macros.h>
 #include <kern/percpu.h>
 #include <machine/lapic.h>
@@ -614,24 +615,16 @@ void * cpu_get_boot_stack(void);
 
 /*
  * Install an interrupt handler in the IDT.
+ *
+ * These functions may be called before the cpu module is initialized.
  */
 void cpu_idt_set_gate(unsigned int vector, void (*isr)(void));
 void cpu_idt_set_double_fault(void (*isr)(void));
 
 /*
- * Set up the cpu module.
- */
-void cpu_setup(void);
-
-/*
- * Make sure the CPU has some required features.
- */
-void cpu_check(const struct cpu *cpu);
-
-/*
- * Display processor information.
+ * Log processor information.
  */
-void cpu_info(const struct cpu *cpu);
+void cpu_log_info(const struct cpu *cpu);
 
 /*
  * Register the presence of a local APIC.
@@ -639,13 +632,6 @@ void cpu_info(const struct cpu *cpu);
 void cpu_mp_register_lapic(unsigned int apic_id, int is_bsp);
 
 /*
- * Probe application processors.
- *
- * On return, cpu_count() gives the actual number of managed processors.
- */
-void cpu_mp_probe(void);
-
-/*
  * Start application processors.
  *
  * The x86 architecture uses per-CPU page tables, which are created as a
@@ -696,6 +682,26 @@ cpu_send_thread_schedule(unsigned int cpu)
  */
 void cpu_thread_schedule_intr(struct trap_frame *frame);
 
+/*
+ * This init operation provides :
+ *  - initialization of the BSP structure.
+ *  - cpu_delay()
+ *  - cpu_local_ptr() and cpu_local_var()
+ */
+INIT_OP_DECLARE(cpu_setup);
+
+/*
+ * This init operation provides :
+ *  - cpu_count()
+ */
+INIT_OP_DECLARE(cpu_mp_probe);
+
+/*
+ * This init operation provides :
+ *  - cpu shutdown operations registered
+ */
+INIT_OP_DECLARE(cpu_setup_shutdown);
+
 #endif /* __ASSEMBLER__ */
 
 #endif /* _X86_CPU_H */
diff --git a/arch/x86/machine/pmap.c b/arch/x86/machine/pmap.c
index 93b68758..7ab70bfd 100644
--- a/arch/x86/machine/pmap.c
+++ b/arch/x86/machine/pmap.c
@@ -828,7 +828,7 @@ pmap_syncer_init(struct pmap_syncer *syncer, unsigned int cpu)
     syscnt_register(&syncer->sc_update_protects, name);
 }
 
-void __init
+static int __init
 pmap_bootstrap(void)
 {
     struct pmap_cpu_table *cpu_table;
@@ -864,20 +864,17 @@ pmap_bootstrap(void)
     if (cpu_has_global_pages()) {
         pmap_setup_global_pages();
     }
-}
 
-void __init
-pmap_ap_bootstrap(void)
-{
-    cpu_local_assign(pmap_current_ptr, kernel_pmap);
-
-    if (cpu_has_global_pages()) {
-        cpu_enable_global_pages();
-    } else {
-        cpu_tlb_flush();
-    }
+    return 0;
 }
 
+INIT_OP_DEFINE(pmap_bootstrap,
+               INIT_OP_DEP(cpu_setup, true),
+               INIT_OP_DEP(mutex_setup, true),
+               INIT_OP_DEP(spinlock_setup, true),
+               INIT_OP_DEP(syscnt_setup, true),
+               INIT_OP_DEP(thread_bootstrap, true));
+
 static void __init
 pmap_setup_set_ptp_type(phys_addr_t ptp_pa, unsigned int index,
                         unsigned int level)
@@ -906,7 +903,7 @@ pmap_setup_fix_ptps(void)
                   pmap_setup_set_ptp_type);
 }
 
-void __init
+static int __init
 pmap_setup(void)
 {
     pmap_setup_fix_ptps();
@@ -914,6 +911,25 @@ pmap_setup(void)
     kmem_cache_init(&pmap_update_oplist_cache, "pmap_update_oplist",
                     sizeof(struct pmap_update_oplist), CPU_L1_SIZE,
                     pmap_update_oplist_ctor, 0);
+    return 0;
+}
+
+INIT_OP_DEFINE(pmap_setup,
+               INIT_OP_DEP(kmem_setup, true),
+               INIT_OP_DEP(log_setup, true),
+               INIT_OP_DEP(pmap_bootstrap, true),
+               INIT_OP_DEP(vm_page_setup, true));
+
+void __init
+pmap_ap_setup(void)
+{
+    cpu_local_assign(pmap_current_ptr, kernel_pmap);
+
+    if (cpu_has_global_pages()) {
+        cpu_enable_global_pages();
+    } else {
+        cpu_tlb_flush();
+    }
 }
 
 static void __init
diff --git a/arch/x86/machine/pmap.h b/arch/x86/machine/pmap.h
index 84042583..114dcdac 100644
--- a/arch/x86/machine/pmap.h
+++ b/arch/x86/machine/pmap.h
@@ -165,6 +165,7 @@
 #include <stdint.h>
 
 #include <kern/cpumap.h>
+#include <kern/init.h>
 #include <kern/list.h>
 #include <kern/mutex.h>
 #include <kern/thread.h>
@@ -203,22 +204,9 @@ pmap_pte_t * pmap_setup_paging(void);
 pmap_pte_t * pmap_ap_setup_paging(void);
 
 /*
- * Early initialization of the pmap module.
+ * Initialize the pmap module on APs.
  */
-void pmap_bootstrap(void);
-
-/*
- * Early initialization of the MMU on APs.
- */
-void pmap_ap_bootstrap(void);
-
-/*
- * Set up the pmap module.
- *
- * This function should only be called by the VM system, once kernel
- * allocations can be performed safely.
- */
-void pmap_setup(void);
+void pmap_ap_setup(void);
 
 /*
  * Set up the pmap module for multiprocessor operations.
@@ -330,6 +318,19 @@ pmap_current(void)
     return cpu_local_read(pmap_current_ptr);
 }
 
+/*
+ * This init operation provides :
+ *  - kernel pmap operations
+ */
+INIT_OP_DECLARE(pmap_bootstrap);
+
+/*
+ * This init operation provides :
+ *  - user pmap creation
+ *  - module fully initialized
+ */
+INIT_OP_DECLARE(pmap_setup);
+
 #endif /* __ASSEMBLER__ */
 
 #endif /* _X86_PMAP_H */
diff --git a/arch/x86/machine/strace.c b/arch/x86/machine/strace.c
index 4b7e7438..cfb237e1 100644
--- a/arch/x86/machine/strace.c
+++ b/arch/x86/machine/strace.c
@@ -36,6 +36,8 @@
 #define STRACE_ADDR_FORMAT "%#010lx"
 #endif /* __LP64__ */
 
+static const struct multiboot_raw_info *strace_mbi __initdata;
+
 static struct elf_sym *strace_symtab __read_mostly;
 static struct elf_sym *strace_symtab_end __read_mostly;
 static char *strace_strtab __read_mostly;
@@ -173,14 +175,23 @@ strace_lookup_section(const struct multiboot_raw_info *mbi, const void *table,
 }
 
 void __init
-strace_setup(const struct multiboot_raw_info *mbi)
+strace_set_mbi(const struct multiboot_raw_info *mbi)
+{
+    strace_mbi = mbi;
+}
+
+static int __init
+strace_setup(void)
 {
     const struct elf_shdr *shstrtab_hdr, *symtab_hdr, *strtab_hdr;
+    const struct multiboot_raw_info *mbi;
     uintptr_t map_addr, shstrtab_map_addr;
     size_t size, map_size, shstrtab_map_size;
     const char *shstrtab;
     const void *table;
 
+    mbi = strace_mbi;
+
     if (!(mbi->flags & MULTIBOOT_LOADER_SHDR) || (mbi->shdr_num == 0)) {
         goto no_syms;
     }
@@ -236,7 +247,7 @@ strace_setup(const struct multiboot_raw_info *mbi)
 
     vm_kmem_unmap_pa(shstrtab_map_addr, shstrtab_map_size);
     vm_kmem_unmap_pa(map_addr, map_size);
-    return;
+    return 0;
 
 error_strtab:
     kmem_free(strace_symtab, symtab_hdr->size);
@@ -251,4 +262,12 @@ no_syms:
     strace_symtab = NULL;
     strace_symtab_end = NULL;
     strace_strtab = NULL;
+    return 0;
 }
+
+INIT_OP_DEFINE(strace_setup,
+               INIT_OP_DEP(kmem_setup, true),
+               INIT_OP_DEP(log_setup, true),
+               INIT_OP_DEP(pmap_bootstrap, true),
+               INIT_OP_DEP(printf_setup, true),
+               INIT_OP_DEP(vm_kmem_setup, true));
diff --git a/arch/x86/machine/strace.h b/arch/x86/machine/strace.h
index 66aa18b7..2f686a07 100644
--- a/arch/x86/machine/strace.h
+++ b/arch/x86/machine/strace.h
@@ -21,6 +21,7 @@
 #ifndef _X86_STRACE_H
 #define _X86_STRACE_H
 
+#include <kern/init.h>
 #include <kern/macros.h>
 #include <machine/multiboot.h>
 
@@ -45,10 +46,17 @@ strace_dump(void)
 }
 
 /*
- * Setup the stack tracing module.
+ * Pass the multiboot information structure.
  *
- * If available, the symbol table is extracted from the boot data.
+ * If available, the symbol table is extracted from the boot data, when
+ * the strace module is initialized.
  */
-void strace_setup(const struct multiboot_raw_info *mbi);
+void strace_set_mbi(const struct multiboot_raw_info *mbi);
+
+/*
+ * This init operation provides :
+ *  - module fully initialized
+ */
+INIT_OP_DECLARE(strace_setup);
 
 #endif /* _X86_STRACE_H */
diff --git a/arch/x86/machine/tcb.c b/arch/x86/machine/tcb.c
index fb31a172..b54945c7 100644
--- a/arch/x86/machine/tcb.c
+++ b/arch/x86/machine/tcb.c
@@ -104,3 +104,12 @@ tcb_trace(const struct tcb *tcb)
 {
     strace_show((uintptr_t)tcb_context_restore, tcb->bp);
 }
+
+static int __init
+tcb_setup(void)
+{
+    return 0;
+}
+
+INIT_OP_DEFINE(tcb_setup,
+               INIT_OP_DEP(cpu_setup, true));
diff --git a/arch/x86/machine/tcb.h b/arch/x86/machine/tcb.h
index 9c69a5ee..9107f7c4 100644
--- a/arch/x86/machine/tcb.h
+++ b/arch/x86/machine/tcb.h
@@ -25,6 +25,7 @@
 #include <stdint.h>
 #include <stdnoreturn.h>
 
+#include <kern/init.h>
 #include <machine/cpu.h>
 #include <machine/page.h>
 
@@ -95,4 +96,10 @@ tcb_switch(struct tcb *prev, struct tcb *next)
  */
 void tcb_trace(const struct tcb *tcb);
 
+/*
+ * This init operation provides :
+ *  - current TCB handling
+ */
+INIT_OP_DECLARE(tcb_setup);
+
 #endif /* _X86_TCB_H */
diff --git a/arch/x86/machine/trap.c b/arch/x86/machine/trap.c
index 1580fa53..878f20c9 100644
--- a/arch/x86/machine/trap.c
+++ b/arch/x86/machine/trap.c
@@ -171,7 +171,7 @@ trap_default(struct trap_frame *frame)
     cpu_halt();
 }
 
-void __init
+static int __init
 trap_setup(void)
 {
     size_t i;
@@ -213,8 +213,12 @@ trap_setup(void)
     trap_install(TRAP_LAPIC_TIMER, TRAP_HF_INTR, lapic_timer_intr);
     trap_install(TRAP_LAPIC_ERROR, TRAP_HF_INTR, lapic_error_intr);
     trap_install(TRAP_LAPIC_SPURIOUS, TRAP_HF_INTR, lapic_spurious_intr);
+
+    return 0;
 }
 
+INIT_OP_DEFINE(trap_setup);
+
 void
 trap_main(struct trap_frame *frame)
 {
diff --git a/arch/x86/machine/trap.h b/arch/x86/machine/trap.h
index f8d0a16f..699f19e7 100644
--- a/arch/x86/machine/trap.h
+++ b/arch/x86/machine/trap.h
@@ -77,6 +77,7 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#include <kern/init.h>
 #include <kern/macros.h>
 
 #ifdef __LP64__
@@ -144,11 +145,6 @@ trap_trigger_double_fault(void)
 }
 
 /*
- * Set up the trap module.
- */
-void trap_setup(void);
-
-/*
  * Unified trap entry point.
  */
 void trap_main(struct trap_frame *frame);
@@ -177,6 +173,13 @@ void trap_stack_show(struct trap_frame *frame);
  */
 void * trap_get_interrupt_stack(const struct trap_frame *frame);
 
+/*
+ * This init operation provides :
+ *  - initialization of all IDT entries and trap handlers
+ *  - double fault exception support
+ */
+INIT_OP_DECLARE(trap_setup);
+
 #endif /* __ASSEMBLER__ */
 
 #endif /* _X86_TRAP_H */
diff --git a/arch/x86/machine/uart.c b/arch/x86/machine/uart.c
index cdb49a90..10a32886 100644
--- a/arch/x86/machine/uart.c
+++ b/arch/x86/machine/uart.c
@@ -407,7 +407,23 @@ uart_init(struct uart *uart, uint16_t port, uint16_t intr)
     console_register(&uart->console);
 }
 
-void __init
+static void __init
+uart_log_info(void)
+{
+    const struct uart *uart;
+    size_t i;
+
+    for (i = 0; i < ARRAY_SIZE(uart_devs); i++) {
+        uart = uart_get_dev(i);
+
+        if (uart->port != 0) {
+            log_info("uart%zu: port:%#x irq:%u", i, (unsigned int)uart->port,
+                     (unsigned int)uart->intr);
+        }
+    }
+}
+
+static int __init
 uart_bootstrap(void)
 {
     const uint16_t *ptr;
@@ -422,9 +438,17 @@ uart_bootstrap(void)
 
         uart_init(uart_get_dev(i), ptr[i], uart_intrs[i]);
     }
+
+    uart_log_info();
+    return 0;
 }
 
-void __init
+INIT_OP_DEFINE(uart_bootstrap,
+               INIT_OP_DEP(arg_setup, true),
+               INIT_OP_DEP(console_bootstrap, true),
+               INIT_OP_DEP(log_setup, true));
+
+static int __init
 uart_setup(void)
 {
     struct uart *uart;
@@ -439,20 +463,10 @@ uart_setup(void)
 
         uart_enable_intr(uart);
     }
-}
 
-void __init
-uart_info(void)
-{
-    const struct uart *uart;
-    size_t i;
-
-    for (i = 0; i < ARRAY_SIZE(uart_devs); i++) {
-        uart = uart_get_dev(i);
-
-        if (uart->port != 0) {
-            log_info("uart%zu: port:%#x irq:%u", i, (unsigned int)uart->port,
-                     (unsigned int)uart->intr);
-        }
-    }
+    return 0;
 }
+
+INIT_OP_DEFINE(uart_setup,
+               INIT_OP_DEP(intr_setup, true),
+               INIT_OP_DEP(uart_bootstrap, true));
diff --git a/arch/x86/machine/uart.h b/arch/x86/machine/uart.h
index 60b195c6..0054da86 100644
--- a/arch/x86/machine/uart.h
+++ b/arch/x86/machine/uart.h
@@ -21,24 +21,19 @@
 #ifndef _X86_UART_H
 #define _X86_UART_H
 
-/*
- * Early initialization of the uart module.
- *
- * Devices may only be used to report diagnostics until initialization
- * is completed.
- */
-void uart_bootstrap(void);
+#include <kern/init.h>
 
 /*
- * Initialize the uart module.
- *
- * On return, devices may be used for both input and output, using interrupts.
+ * This init operation provides :
+ *  - UART output through the console module
  */
-void uart_setup(void);
+INIT_OP_DECLARE(uart_bootstrap);
 
 /*
- * Display device information.
+ * This init operation provides :
+ *  - UART input through the console module
+ *  - module fully initialized
  */
-void uart_info(void);
+INIT_OP_DECLARE(uart_setup);
 
 #endif /* _X86_UART_H */