Kernel: Make the kernel compile & link for x86_64

It's now possible to build the whole kernel with an x86_64 toolchain.
There's no bootstrap code so it doesn't work yet (obviously.)

4 files changed, 240 insertions, 9 deletions

diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp
index 6187bffc97..970483382d 100644
--- a/Kernel/Arch/i386/CPU.cpp
+++ b/Kernel/Arch/i386/CPU.cpp
@@ -76,6 +76,7 @@ extern "C" void handle_interrupt(TrapFrame*);
 
 // clang-format off
 
+#if ARCH(I386)
 #define EH_ENTRY(ec, title)                         \
     extern "C" void title##_asm_entry();            \
     extern "C" void title##_handler(TrapFrame*); \
@@ -127,6 +128,26 @@ extern "C" void handle_interrupt(TrapFrame*);
         "    call " #title "_handler\n"             \
         "    jmp common_trap_exit \n");
 
+#elif ARCH(X86_64)
+#define EH_ENTRY(ec, title)                         \
+    extern "C" void title##_asm_entry();            \
+    extern "C" void title##_handler(TrapFrame*);    \
+    asm(                                            \
+        ".globl " #title "_asm_entry\n"             \
+        "" #title "_asm_entry: \n"                  \
+        "    cli;hlt;\n"                            \
+);
+
+#define EH_ENTRY_NO_CODE(ec, title)                 \
+    extern "C" void title##_handler(TrapFrame*);    \
+    extern "C" void title##_asm_entry();            \
+asm(                                                \
+        ".globl " #title "_asm_entry\n"             \
+        "" #title "_asm_entry: \n"                  \
+        "    cli;hlt;\n"                            \
+);
+#endif
+
 // clang-format on
 
 static void dump(const RegisterState& regs)
@@ -1593,6 +1614,7 @@ extern "C" u32 do_init_context(Thread* thread, u32 flags)
 
 extern "C" void do_assume_context(Thread* thread, u32 flags);
 
+#if ARCH(I386)
 // clang-format off
 asm(
 ".global do_assume_context \n"
@@ -1614,8 +1636,9 @@ asm(
 "    jmp enter_thread_context \n"
 );
 // clang-format on
+#endif
 
-void Processor::assume_context(Thread& thread, u32 flags)
+void Processor::assume_context(Thread& thread, FlatPtr flags)
 {
     dbgln_if(CONTEXT_SWITCH_DEBUG, "Assume context for thread {} {}", VirtualAddress(&thread), thread);
 
@@ -1624,7 +1647,12 @@ void Processor::assume_context(Thread& thread, u32 flags)
     // in_critical() should be 2 here. The critical section in Process::exec
     // and then the scheduler lock
     VERIFY(Processor::current().in_critical() == 2);
+#if ARCH(I386)
     do_assume_context(&thread, flags);
+#elif ARCH(X86_64)
+    (void)flags;
+    TODO();
+#endif
     VERIFY_NOT_REACHED();
 }
 
@@ -2315,12 +2343,14 @@ UNMAP_AFTER_INIT void Processor::gdt_init()
         : "memory");
     set_fs(GDT_SELECTOR_PROC);
 
+#if ARCH(I386)
     // Make sure CS points to the kernel code descriptor.
     // clang-format off
     asm volatile(
         "ljmpl $" __STRINGIFY(GDT_SELECTOR_CODE0) ", $sanity\n"
         "sanity:\n");
     // clang-format on
+#endif
 }
 
 void copy_kernel_registers_into_ptrace_registers(PtraceRegisters& ptrace_regs, const RegisterState& kernel_regs)
diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h
index e343369a29..84ed4b05e5 100644
--- a/Kernel/Arch/i386/CPU.h
+++ b/Kernel/Arch/i386/CPU.h
@@ -1014,7 +1014,7 @@ public:
 
     [[noreturn]] void initialize_context_switching(Thread& initial_thread);
     void switch_context(Thread*& from_thread, Thread*& to_thread);
-    [[noreturn]] static void assume_context(Thread& thread, u32 flags);
+    [[noreturn]] static void assume_context(Thread& thread, FlatPtr flags);
     u32 init_context(Thread& thread, bool leave_crit);
     static Vector<FlatPtr> capture_stack_trace(Thread& thread, size_t max_frames = 0);
 
diff --git a/Kernel/Arch/i386/Interrupts.h b/Kernel/Arch/i386/Interrupts.h
index 7d4e4b69ba..cfa457da16 100644
--- a/Kernel/Arch/i386/Interrupts.h
+++ b/Kernel/Arch/i386/Interrupts.h
@@ -32,13 +32,15 @@
 
 extern "C" void interrupt_common_asm_entry();
 
-#define GENERATE_GENERIC_INTERRUPT_HANDLER_ASM_ENTRY(isr_number) \
-    extern "C" void interrupt_##isr_number##_asm_entry();        \
-    asm(".globl interrupt_" #isr_number "_asm_entry\n"           \
-        "interrupt_" #isr_number "_asm_entry:\n"                 \
-        "    pushw $" #isr_number "\n"                           \
-        "    pushw $0\n"                                         \
-        "    jmp interrupt_common_asm_entry\n");
+#if ARCH(I386)
+
+#    define GENERATE_GENERIC_INTERRUPT_HANDLER_ASM_ENTRY(isr_number) \
+        extern "C" void interrupt_##isr_number##_asm_entry();        \
+        asm(".globl interrupt_" #isr_number "_asm_entry\n"           \
+            "interrupt_" #isr_number "_asm_entry:\n"                 \
+            "    pushw $" #isr_number "\n"                           \
+            "    pushw $0\n"                                         \
+            "    jmp interrupt_common_asm_entry\n");
 
 // clang-format off
 asm(
@@ -83,3 +85,19 @@ asm(
     "    iret\n"
 );
 // clang-format on
+
+#elif ARCH(X86_64)
+
+#    define GENERATE_GENERIC_INTERRUPT_HANDLER_ASM_ENTRY(isr_number) \
+        extern "C" void interrupt_##isr_number##_asm_entry();        \
+        asm(".globl interrupt_" #isr_number "_asm_entry\n"           \
+            "interrupt_" #isr_number "_asm_entry:\n"                 \
+            "    cli\n"                                              \
+            "    hlt\n");
+
+asm(
+    ".globl common_trap_exit\n"
+    "common_trap_exit:\n"
+    "    cli;hlt\n");
+
+#endif
diff --git a/Kernel/Arch/x86_64/Boot/boot.S b/Kernel/Arch/x86_64/Boot/boot.S
new file mode 100644
index 0000000000..1ed1cd9207
--- /dev/null
+++ b/Kernel/Arch/x86_64/Boot/boot.S
@@ -0,0 +1,183 @@
+.set MULTIBOOT_MAGIC,         0x1badb002
+.set MULTIBOOT_PAGE_ALIGN,    0x1
+.set MULTIBOOT_MEMORY_INFO,   0x2
+.set MULTIBOOT_VIDEO_MODE,    0x4
+.set multiboot_flags,         MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO | MULTIBOOT_VIDEO_MODE
+.set multiboot_checksum,      -(MULTIBOOT_MAGIC + multiboot_flags)
+
+.section .multiboot
+.align 4
+
+.long MULTIBOOT_MAGIC
+.long multiboot_flags
+.long multiboot_checksum
+
+
+/* for MULTIBOOT_MEMORY_INFO */
+.long 0x00000000    /* header_addr */
+.long 0x00000000    /* load_addr */
+.long 0x00000000    /* load_end_addr */
+.long 0x00000000    /* bss_end_addr */
+.long 0x00000000    /* entry_addr */
+
+/* for MULTIBOOT_VIDEO_MODE */
+.long 0x00000000    /* mode_type */
+.long 1280          /* width */
+.long 1024          /* height */
+.long 32            /* depth */
+
+.section .stack, "aw", @nobits
+stack_bottom:
+.skip 32768
+stack_top:
+
+.global kernel_cmdline
+kernel_cmdline:
+.skip 4096
+
+.section .page_tables, "aw", @nobits
+.align 4096
+.global boot_pdpt
+boot_pdpt:
+.skip 4096
+.global boot_pd0
+boot_pd0:
+.skip 4096
+.global boot_pd3
+boot_pd3:
+.skip 4096
+.global boot_pd0_pt0
+boot_pd0_pt0:
+.skip 4096 * 4
+.global boot_pd3_pts
+boot_pd3_pts:
+.skip 4096 * 8
+.global boot_pd3_pt1023
+boot_pd3_pt1023:
+.skip 4096
+
+.section .text
+
+.global start
+.type start, @function
+
+.extern init
+.type init, @function
+
+.extern multiboot_info_ptr
+.type multiboot_info_ptr, @object
+
+start:
+    cli
+    cld
+
+    /* We don't know where the bootloader might have put the command line.
+     * It might be at an inconvenient location that we're not about to map,
+     * so let's just copy it to a convenient location while we have the whole
+     * memory space identity-mapped anyway. :^)
+     */
+
+    movl %ebx, %esi
+    addl $16, %esi
+    movl (%esi), %esi
+    movl $1024, %ecx
+    movl $(kernel_cmdline - 0xc0000000), %edi
+    rep movsl
+
+    call init
+    add $4, %esp
+
+    cli
+loop:
+    hlt
+    jmp loop
+
+.extern init_ap
+.type init_ap, @function
+
+/*
+  The apic_ap_start function will be loaded to P0x00008000 where the APIC
+  will boot the AP from in real mode. This code also contains space for
+  special variables that *must* remain here. When initializing the APIC,
+  the code here gets copied to P0x00008000, the variables in here get
+  populated and then the the boot of the APs will be triggered. Having
+  the variables here allows us to access them from real mode. Also, the
+  code here avoids the need for relocation entries.
+
+  Basically, the variables between apic_ap_start and end_apic_ap_start
+  *MUST* remain here and cannot be moved into a .bss or any other location.
+*/
+.global apic_ap_start
+.type apic_ap_start, @function
+apic_ap_start:
+.code16
+    cli
+    jmp $0x800, $(1f - apic_ap_start) /* avoid relocation entries */
+1:
+    mov %cs, %ax
+    mov %ax, %ds
+
+    xor %ax, %ax
+    mov %ax, %sp
+
+    /* load the first temporary gdt */
+    lgdt (ap_cpu_gdtr_initial - apic_ap_start)
+
+    /* enable PM */
+    movl %cr0, %eax
+    orl $1, %eax
+    movl %eax, %cr0
+
+    ljmpl $8, $(apic_ap_start32 - apic_ap_start + 0x8000)
+apic_ap_start32:
+.code32
+    cli
+    hlt
+
+.align 4
+.global apic_ap_start_size
+apic_ap_start_size:
+    .2byte end_apic_ap_start - apic_ap_start
+.align 4
+ap_cpu_id:
+    .4byte 0x0
+ap_cpu_gdt:
+    /* null */
+    .8byte 0x0
+    /* code */
+    .4byte 0x0000FFFF
+    .4byte 0x00cf9a00
+    /* data */
+    .4byte 0x0000FFFF
+    .4byte 0x00cf9200
+ap_cpu_gdt_end:
+ap_cpu_gdtr_initial:
+    .2byte ap_cpu_gdt_end - ap_cpu_gdt - 1
+    .4byte (ap_cpu_gdt - apic_ap_start) + 0x8000
+ap_cpu_gdtr_initial2:
+    .2byte ap_cpu_gdt_end - ap_cpu_gdt - 1
+    .4byte (ap_cpu_gdt - apic_ap_start) + 0xc0008000
+.global ap_cpu_gdtr
+ap_cpu_gdtr:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_idtr
+ap_cpu_idtr:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_init_cr0
+ap_cpu_init_cr0:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_init_cr3
+ap_cpu_init_cr3:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_init_cr4
+ap_cpu_init_cr4:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_init_processor_info_array
+ap_cpu_init_processor_info_array:
+    .4byte 0x0 /* will be set at runtime */
+.global ap_cpu_init_stacks
+ap_cpu_init_stacks:
+    /* array of allocated stack pointers */
+    /* NOTE: ap_cpu_init_stacks must be the last variable before
+             end_apic_ap_start! */
+.set end_apic_ap_start, .