multiboot stuff

CMakeLists.txt

@@ -36,7 +36,7 @@ set(CC_FLAGS
         -std=c17
         -c
         -g
-        -Og
+        -O0
         -Wall
         -Wextra
         -Wpedantic
@@ -55,6 +55,7 @@ set(LD_FLAGS
         -fuse-ld=${LD}
         -nostdlib
         -Wl,--fatal-warnings
+        -Wl,--build-id=none
         ${LD_FLAGS_${ARCH}})
 
 set(PP_FLAGS
@@ -92,7 +93,7 @@ set(TARGET ${proj}_elf)
 set(OBJ_${TARGET} ${CMAKE_CURRENT_BINARY_DIR}/${proj}.elf)
 add_custom_command(
         OUTPUT ${OBJ_${TARGET}}
-        DEPENDS ${TARGETS}
+        DEPENDS ${TARGETS} ${OBJS}
         COMMAND ${CC} ${LD_FLAGS} -Wl,-T, ${SCRIPT_LD} -o ${OBJ_${TARGET}} ${OBJS})
 
 add_custom_target(${TARGET} ALL
@@ -105,7 +106,7 @@ set(OBJ_${TARGET} ${CMAKE_CURRENT_BINARY_DIR}/${proj}.dmp)
 
 add_custom_command(
         OUTPUT ${OBJ_${TARGET}}
-        DEPENDS ${proj}_elf
+        DEPENDS ${proj}.elf
         COMMAND ${DMP} ${DMP_FLAGS} ${OBJ_${proj}_elf} > ${OBJ_${TARGET}}
 )
 add_custom_target(${proj}_dmp ALL
@@ -118,7 +119,7 @@ set(OBJ_${TARGET} ${CMAKE_CURRENT_BINARY_DIR}/${proj}.iso)
 
 add_custom_command(
         OUTPUT ${OBJ_${TARGET}}
-        DEPENDS ${proj}_elf ${TARGET_scripts}
+        DEPENDS ${proj}.elf
         COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/tmp_iso
         COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/tmp_iso/boot
         COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/tmp_iso/boot/grub

arch/CMakeLists.txt

@@ -1,7 +1,7 @@
 set(SUBMODULE arch)
 set(CC_SRC
         cpu.c
-        init.c
+        main.c
         intr.c
         mem.c
         print.c

arch/boot.asm

@@ -1,58 +1,81 @@
 #define ASM_FILE
 #include <arch/mlayout.h>
 #include "multiboot2.h"
-
+%define BOCHS_BREAK xchg bx, bx
-%define GET_PADDR(x) ((x) - KERNEL_IMG_VADDR)
+%define GET_PADDR(x) ((x) - KERN_BASE_START)
 %define GET_PML4(vaddr) (((vaddr) >> 39 ) & 0x1FF)
 %define GET_PDPT(vaddr) (((vaddr) >> 30 ) & 0x1FF)
+%define GET_PDE(vaddr) (((vaddr) >> 21 ) & 0x1FF)
 
+; make arch_init_32 visiable
 global arch_init_32
+
+; arch_main is the C long mode entry point
 extern arch_main
 
 section .text
 bits 32
+; the bootloader calls this dude, we switch to long mode with some basic setup:
+; Identity map the first 4G memory, where the kernel binary and multiboot info is
+; Map the first 4G memory to KERN_PMAP temporarily so we have access to printf
+; Map the first 1G memory, which contains the kernel, to KERN_BASE_START
 arch_init_32:
-    cli
+    cli ; close interrupt
-    cld
+    cld ; set direction
-    cmp eax, MULTIBOOT2_BOOTLOADER_MAGIC
+    cmp eax, MULTIBOOT2_BOOTLOADER_MAGIC ; compare with multiboot2 magic
-    jne .end
+    jne .end ; if not loaded by multiboot2 compliant bootloader, loop infinitely
+
+    BOCHS_BREAK
 
     ; save multiboot info
     mov dword [GET_PADDR(multiboot_info_ptr)], ebx
 
-    ; setup stack
-    call check_long_mode ; check support for long mode 
-    cmp eax, 1
-    jne .end
-
     ; disable paging first
     mov eax, cr0          ; Set the A-register to control register 0.
     and eax, ~(1 << 31) & 0xFFFFFFFF   ; Clear the PG-bit, which is bit 31, and hack to get rid of warning
     mov cr0, eax          ; Set control register 0 to the A-register.
 
+    ; identity map the first 4G page
+    mov eax, GET_PADDR(kern_early_pml4)
+    add eax, GET_PML4(0) * 8 ; eax = offset of pml4e in pml4 for the 0th GB
+    mov dword [eax], GET_PADDR(kern_early_ident_pdpt) + 11b ; let the corresponding pml4e point to the kern_early_ident_pdpt
+
+    mov eax, GET_PADDR(kern_early_ident_pdpt)
+    add eax, GET_PDPT(0) * 8
+    mov ebx, 10000011b ; ebx lower bits is attribute = R/W + SU + 1G page, high bits = physical 0th GB
+    mov ecx, 4 ; 4 times = 4GB
+    .l0:
+        mov dword [eax], ebx ; set the corresponding pdpte to map 1GB pages in ebx
+        add ebx, 1*1024*1024*1024 ; add another 1G to ebx higher bits
+        add eax, 8 ; increment to next pdpte
+        loop .l0
+
+    ; map the first 4G to pmap
+    mov eax, GET_PADDR(kern_early_pml4)
+    add eax, GET_PML4(KERN_PMAP_START) * 8 ; eax = offset of pml4e in pml4 for PMAP region
+    mov dword [eax], GET_PADDR(kern_early_pmap_pdpt) + 11b ; let the corresponding pml4e point to the kern_early_pmap_pdpt
+
+    mov eax, GET_PADDR(kern_early_pmap_pdpt)
+    add eax, GET_PDPT(KERN_PMAP_START) * 8
+    mov ebx, 10000011b ; ebx lower bits is attribute = R/W + SU + 1G page, high bits = physical 0th GB
+    mov ecx, 4 ; 4 times = 4GB
+    .l1:
+        mov dword [eax], ebx ; set the corresponding pdpte to map 1GB pages in ebx
+        add ebx, 1*1024*1024*1024 ; add another 1G to ebx higher bits
+        add eax, 8 ; increment to next pdpte
+        loop .l1
+
+    ; map the first 1G to kern_base
     ; point the first PML4 entry to the identity pdpt
-    mov eax, GET_PADDR(init_pml4)
+    mov eax, GET_PADDR(kern_early_pml4)
-    mov dword [eax], GET_PADDR(init_pdpt_iden) + 11b ; write the lower bits, higher = 0
+    add eax, GET_PML4(KERN_BASE_START) * 8
-    ; point the nth PML4 entry to the kernel pdpt
+    mov dword [eax], GET_PADDR(kern_early_img_pdpt) + 11b ; let the corresponding pml4e point to the kern_early_img_pdpt
-    add eax, GET_PML4(KERNEL_SPACE_VADDR) * 8
-    mov dword [eax], GET_PADDR(init_pdpt_kern) + 11b
 
-    ; identity map the first 4GB
+    mov eax, GET_PADDR(kern_early_img_pdpt)
-    mov eax, GET_PADDR(init_pdpt_iden)
+    add eax, GET_PDPT(KERN_BASE_START) * 8
-    mov ebx, 10000011b ; R/W + SU + 1G page
+    mov dword [eax], 10000011b ; ebx lower bits is attribute = R/W + SU + 1G page, high bits = physical 0th GB
-    mov ecx, 4 ; loop 4 times
-.l0:
-    mov dword [eax], ebx
-    add ebx, 1*1024*1024*1024 ; 1G
-    add eax, 8
-    loop .l0
 
-    ; map the first 1 GB, which contains the kernel, to KERNEL_BASE_VADDR
+    BOCHS_BREAK
-    mov eax, GET_PADDR(init_pdpt_kern)
-    ; extract the PML4 entry
-    add eax, GET_PDPT(KERNEL_SPACE_VADDR) * 8
-    mov ebx, 10000011b ; R/W + SU + 1G page
-    mov dword [eax], ebx
 
     ; enable PAE
     mov eax, cr4                 ; Set the A-register to control register 4.
@@ -66,56 +89,25 @@ arch_init_32:
     wrmsr                        ; Write to the model-specific register.
 
     ; let cr3 point at page table
-    mov eax, GET_PADDR(init_pml4)
+    mov eax, GET_PADDR(kern_early_pml4)
     mov cr3, eax
 
+    xchg bx, bx
     ; enable paging, enter compatibility mode
     mov eax, cr0                                   ; Set the A-register to control register 0.
     or eax, 1 << 31                                ; Set the PG-bit, which is bit 31.
     mov cr0, eax                                   ; Set control register 0 to the A-register.
 
     ; now we are in compat mode
-
     ; load the long mode GDT
-    lgdt [GET_PADDR(init_gdt.ptr)]
+    lgdt [GET_PADDR(kern_early_gdt.ptr)]
 
 	; switch to long mode
-    jmp init_gdt.code:GET_PADDR(arch_init_64)
+    jmp kern_early_gdt.code:GET_PADDR(arch_init_64)
+    ; should not reach this point
 .end:
     jmp $
 
-check_long_mode:
-    push ebp
-    mov ebp,esp
-    pushfd
-    pop eax
-    mov ecx, eax
-    xor eax, 1 << 21
-    push eax
-    popfd
-    pushfd
-    pop eax
-    push ecx
-    popfd
-    xor eax, ecx
-    jz .not_supported
-    mov eax, 0x80000000    ; Set the A-register to 0x80000000.
-    cpuid                  ; CPU identification.
-    cmp eax, 0x80000001    ; Compare the A-register with 0x80000001.
-    jb .not_supported      ; It is less, there is no long mode.
-    mov eax, 0x80000001    ; Set the A-register to 0x80000001.
-    cpuid                  ; CPU identification.
-    test edx, 1 << 29      ; Test if the LM-bit, which is bit 29, is set in the D-register.
-    jz .not_supported      ; They arent, there is no long mode.
-    mov eax,1
-    jmp .end
-.not_supported:
-    xor eax,eax
-.end:
-    mov esp,ebp
-    pop ebp
-    ret
-
 section .data
 bits 32
 multiboot_info_ptr: 
@@ -130,7 +122,7 @@ arch_init_64:
 	jmp rax
 .high:
     ; set proper segment registers
-    mov ax,init_gdt.data
+    mov ax,kern_early_gdt.data
     mov ds,ax
     mov es,ax
     mov fs,ax
@@ -138,49 +130,53 @@ arch_init_64:
     mov ss,ax
 
     ; initial kernel stack, 4k
-    mov rsp, init_stack
+    mov rsp, kern_early_stack
     xor rdi, rdi
     mov edi, dword [multiboot_info_ptr]
     ; init arch
     call arch_main
-.end:
+    ; should not reach this point
-    hlt
+    jmp $
 
 
 section .data
 bits 64
-align KERNEL_PAGE_SIZE
+align 0x1000
-    times KERNEL_PAGE_SIZE db 0
+    times KERN_PAGE_SZ db 0
-init_stack:
+kern_early_stack:
 
-init_pml4:
+align 0x1000
-align KERNEL_PAGE_SIZE
+kern_early_pml4:
-    times KERNEL_PAGE_SIZE db 0
+    times 0x1000 db 0
 
-init_pdpt_iden:
+align 0x1000
-align KERNEL_PAGE_SIZE
+kern_early_ident_pdpt:
-    times KERNEL_PAGE_SIZE db 0
+    times 0x1000 db 0
 
-init_pdpt_kern:
+align 0x1000
-align KERNEL_PAGE_SIZE
+kern_early_pmap_pdpt:
-    times KERNEL_PAGE_SIZE db 0
+    times 0x1000 db 0
 
-init_gdt:                        ; Global Descriptor Table (long mode).
+align 0x1000
-.null: equ $ - init_gdt         ; The null descriptor.
+kern_early_img_pdpt:
+    times 0x1000 db 0
+
+kern_early_gdt:                        ; Global Descriptor Table (long mode).
+.null: equ $ - kern_early_gdt         ; The null descriptor.
     dw 0                         ; Limit (low).
     dw 0                         ; Base (low).
     db 0                         ; Base (middle)
     db 0                         ; Access.
     db 0                         ; Granularity.
     db 0                         ; Base (high).
-.code: equ $ - init_gdt         ; The code descriptor.
+.code: equ $ - kern_early_gdt    ; The code descriptor.
     dw 0                         ; Limit (low).
     dw 0                         ; Base (low).
     db 0                         ; Base (middle)
     db 10011010b                 ; Access (exec/read).
     db 00100000b                 ; Granularity.
     db 0                         ; Base (high).
-.data: equ $ - init_gdt         ; The data descriptor.
+.data: equ $ - kern_early_gdt    ; The data descriptor.
     dw 0                         ; Limit (low).
     dw 0                         ; Base (low).
     db 0                         ; Base (middle)
@@ -189,5 +185,5 @@ init_gdt:                        ; Global Descriptor Table (long mode).
     db 0                         ; Base (high).
 .ptr:
     ; GDT PTR
-    dw $ - init_gdt - 1             ; Limit.
+    dw $ - kern_early_gdt - 1       ; Limit.
-    dq GET_PADDR(init_gdt)          ; Base.
+    dq GET_PADDR(kern_early_gdt)    ; Base.

arch/init.c

@@ -1,71 +0,0 @@
-#include <kern/cdef.h>
-#include <kern/print.h>
-#include <arch/print.h>
-#include <arch/brute.h>
-
-// private headers
-#include "multiboot2.h"
-
-void arch_main(ATTR_UNUSED void* mb_info)
-{
-    /* init printf related stuff */
-    arch_print_init();
-
-    kprintf("Initializing arch layer...\n");
-
-    arch_brute();
-    
-/*  if (mb_info == NULL)
-    {
-        goto err;
-    }
-
-    char *cur_ptr = (char *) mb_info + 8;
-    char *bootloader_name = NULL;
-
-    while (1)
-    {
-        struct multiboot_tag *cur_tag = (struct multiboot_tag *) cur_ptr;
-        switch (cur_tag->type)
-        {
-            case MULTIBOOT_TAG_TYPE_MMAP:
-                hal_mem_init((struct multiboot_tag_mmap*) cur_ptr);
-                break;
-            case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
-                hal_print_init((struct multiboot_tag_framebuffer *) cur_ptr);
-                break;
-            case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
-                bootloader_name = ((struct multiboot_tag_string*)cur_ptr)->string;
-                break;
-            case MULTIBOOT_TAG_TYPE_ACPI_NEW:
-            default:
-                break;
-        }
-
-        if (cur_tag->type == MULTIBOOT_TAG_TYPE_END)
-        {
-            break;
-        }
-
-        cur_ptr += cur_tag->size;
-        cur_ptr = (char *) ALIGN(uintptr, cur_ptr, 8);
-    }
-    hal_halt_cpu();
-
-    hal_printf("Boot loader:%d\n", bootloader_name);
-
-    struct boot_info *boot_info = halloc(sizeof(struct boot_info));
-
-//    // obtain cpu info
-//    halp_obtain_cpu_info(boot_info);
-
-    // init interrupt
-    if (hal_interrupt_init() != 0)
-    {
-        hal_halt_cpu();
-    }
-
-    kmain(boot_info);
-err:
-    hal_halt_cpu(); */
-}

arch/main.c

@@ -0,0 +1,47 @@
+#include <kern/cdef.h>
+#include <kern/print.h>
+#include <arch/print.h>
+#include <arch/brute.h>
+
+// private headers
+#include "multiboot2.h"
+
+ATTR_USED void
+arch_main(void *mb_info)
+{
+    /* init printf related stuff */
+    arch_print_init();
+
+    kprintf("Multiboot info: 0x%p\n", mb_info);
+    kprintf("Initializing arch layer...\n");
+
+    for (struct multiboot_tag *tag = (struct multiboot_tag *) ((uintptr) mb_info + 8);
+         tag->type != MULTIBOOT_TAG_TYPE_END;
+         tag = (struct multiboot_tag *) ((multiboot_uint8_t *) tag
+                                         + ((tag->size + 7) & ~7u))) {
+        kprintf("Tag 0x%p: %d, Size %d\n", (void *) tag, tag->type, tag->size);
+        switch (tag->type) {
+            case MULTIBOOT_TAG_TYPE_MMAP:
+                for (struct multiboot_mmap_entry *entry = ((struct multiboot_tag_mmap *) tag)->entries;
+                     (multiboot_uint8_t *) entry < (multiboot_uint8_t *) tag + tag->size;
+                     entry = (multiboot_memory_map_t *) ((uintptr) entry +
+                                                         ((struct multiboot_tag_mmap *) tag)->entry_size))
+                    kprintf(" base_addr = 0x%lx,"
+                            " length = 0x%lx, type = 0x%x\n",
+                            (ulong) entry->addr,
+                            (ulong) entry->len,
+                            entry->type);
+                break;
+            case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
+                kprintf("BoND is loaded by: %s\n", ((struct multiboot_tag_string *) tag)->string);
+                break;
+            default:
+                kprintf("Unhandled multiboot tag type: %d\n", tag->type);
+                break;
+        }
+    }
+
+    kprintf("Arch layer initialized.\n");
+
+    arch_brute();
+}

arch/mb_hdr.asm

@@ -2,14 +2,11 @@
 #include "multiboot2.h"
 #include <arch/mlayout.h>
 
-extern hmain
-global hal_main_32
-
 ASM_MULTIBOOT_CHECK_SUM equ (0xFFFFFFFF - (MULTIBOOT2_HEADER_MAGIC + ASM_MULTIBOOT_HEADER_SIZE + MULTIBOOT_ARCHITECTURE_I386) + 1)
 
 section .multiboot_header
 bits 32
-align KERNEL_PAGE_SIZE
+align 0x1000
 ;====================
 align MULTIBOOT_HEADER_ALIGN
 start_hdr:

arch/print.c

@@ -16,6 +16,8 @@ static void
 _fb_scroll()
 {
     memmove(base, base + FB_COL * BYTE_PER_CHAR, FB_SZ - (FB_COL * BYTE_PER_CHAR));
+    // clear the last line
+    memset(base + (FB_ROW - 1) * FB_COL * BYTE_PER_CHAR, 0, FB_COL * BYTE_PER_CHAR);
     text_pos = FB_SZ - (FB_COL * BYTE_PER_CHAR);
 }
 

bochsrc

@@ -0,0 +1,57 @@
+# configuration file generated by Bochs
+plugin_ctrl: unmapped=1, biosdev=1, speaker=1, extfpuirq=1, parallel=1, serial=1, iodebug=1
+config_interface: textconfig
+display_library: x, options="gui_debug"
+memory: host=256, guest=256
+romimage: file="/usr/share/bochs/BIOS-bochs-latest", address=0x0, options=none
+vgaromimage: file="/usr/share/bochs/VGABIOS-lgpl-latest"
+boot: cdrom
+floppy_bootsig_check: disabled=0
+# no floppya
+# no floppyb
+ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
+ata0-master: type=none
+ata0-slave: type=cdrom, path="bond.iso", status=inserted, model="Generic 1234", biosdetect=auto
+ata1: enabled=1, ioaddr1=0x170, ioaddr2=0x370, irq=15
+ata1-master: type=none
+ata1-slave: type=none
+ata2: enabled=0
+ata3: enabled=0
+optromimage1: file=none
+optromimage2: file=none
+optromimage3: file=none
+optromimage4: file=none
+optramimage1: file=none
+optramimage2: file=none
+optramimage3: file=none
+optramimage4: file=none
+pci: enabled=1, chipset=i440fx
+vga: extension=vbe, update_freq=5, realtime=1
+cpu: count=1:1:1, ips=4000000, quantum=16, model=bx_generic, reset_on_triple_fault=0, cpuid_limit_winnt=0, ignore_bad_msrs=1, mwait_is_nop=0
+cpuid: level=6, stepping=3, model=3, family=6, vendor_string="AuthenticAMD", brand_string="AMD Athlon(tm) processor"
+cpuid: mmx=1, apic=x2apic, simd=sse2, sse4a=0, misaligned_sse=0, sep=1, movbe=0, adx=0
+cpuid: aes=0, sha=0, xsave=0, xsaveopt=0, x86_64=1, 1g_pages=1, pcid=0, fsgsbase=0
+cpuid: smep=0, smap=0, mwait=1
+print_timestamps: enabled=0
+debugger_log: -
+magic_break: enabled=1
+port_e9_hack: enabled=0
+private_colormap: enabled=0
+clock: sync=none, time0=local, rtc_sync=0
+# no cmosimage
+# no loader
+log: -
+logprefix: %t%e%d
+debug: action=ignore
+info: action=report
+error: action=report
+panic: action=ask
+keyboard: type=mf, serial_delay=250, paste_delay=100000, user_shortcut=none
+mouse: type=ps2, enabled=0, toggle=ctrl+mbutton
+speaker: enabled=1, mode=system
+parport1: enabled=1, file=none
+parport2: enabled=0
+com1: enabled=1, mode=null
+com2: enabled=0
+com3: enabled=0
+com4: enabled=0

inc/arch/mem.h

@@ -6,5 +6,5 @@
 static inline void *
 arch_pmap_map(uintptr paddr, ATTR_UNUSED usize size)
 {
-    return (void*)(paddr + KERNEL_PMAP_VADDR);
+    return (void*)(paddr + KERN_PMAP_START);
 }

inc/arch/mlayout.h

@@ -3,14 +3,14 @@
 /**
  * Kernel Memory Layout
  * ----------------------- 0x0000,0000,0000,0000 - User Space
- * Application       SIZE: 0x0000,8000,0000,0000 (256x PML4)
+ * Application       SIZE: 0x0000,8000,0000,0000 (256x PML4, 128TB)
  * ----------------------- 0x0000,8000,0000,0000
  * Non-canonical
  * ----------------------- 0xFFFF,8000,0000,0000 - Kernel Space
- * PMAP              SIZE: 0x0000,4000,0000,0000 (128x PML4)
+ * Unused
- * ----------------------- 0xFFFF,C000,0000,0000
+ * ----------------------- 0xFFFF,9000,0000,0000
- * Kernel Dynamic    SIZE: 0x0000,3000,0000,0000
+ * PMAP              SIZE: 0x0000,0400,0000,0000 (8x PML4, 4TB)
- * ----------------------- 0xFFFF,F000,0000,0000
+ * ----------------------- 0xFFFF,9400,0000,0000
  * Unused
  * ----------------------- 0xFFFF,FFFF,8000,0000
  * Kernel Image      SIZE: 0x0000,0000,8000,0000 (2GB)
@@ -18,17 +18,30 @@
 **/
 
 /**
- * kernel loaded at physical address 16MB
+ * kernel loaded at physical address 32MB
- * 0x1000000 = 16777216 = 16 * 1024 * 1024
+ * 0x2000000 = 2 * 16777216 = 2 * 16 * 1024 * 1024
  */
-#define KERNEL_IMG_PADDR       (0x1000000)
+#ifdef ASM_FILE
-#define KERNEL_PAGE_SIZE         (0x1000)
 
-#define KERNEL_SPACE_VADDR       (0xFFFF800000000000)
+#define KERN_IMG_PADDR       0x2000000
-#define KERNEL_PMAP_VADDR        (0xFFFF800000000000)
+#define KERN_PAGE_SZ         0x1000
-#define KERNEL_PMAP_SIZE         (0x0000400000000000)
-#define KERNEL_DYN_VADDR         (0xFFFFFF8000000000)
-#define KERNEL_DYN_SIZE          (0x0000300000000000)
-#define KERNEL_IMG_VADDR         (0xFFFFFFFF80000000)
-#define KERNEL_IMG_SIZE          (0x000000007FFFFFFF)
 
+#define KERN_PMAP_START 0xFFFF900000000000
+#define KERN_PMAP_STOP  0xFFFF940000000000
+#define KERN_BASE_START 0xFFFFFFFF80000000
+#define KERN_BASE_STOP  0x0000000000000000
+
+#else
+
+#define KERN_IMG_PADDR       (0x2000000)
+#define KERN_PAGE_SZ         (0x1000)
+
+extern const char KERN_IMG_START[];
+extern const char KERN_IMG_STOP[];
+
+#define KERN_PMAP_START (0xFFFF900000000000)
+#define KERN_PMAP_STOP  (0xFFFF940000000000)
+#define KERN_BASE_START (0xFFFFFFFF80000000)
+#define KERN_BASE_STOP  (0x0000000000000000)
+
+#endif

inc/kern/cdef.h

@@ -35,3 +35,5 @@ typedef unsigned int uint;
 #define ATTR_SECTION(x) __attribute__ ((section (#x)))
 #define ATTR_ALIGN(x) _Alignas(x)
 #define ATTR_FMT_PRINTF __attribute__((format (printf, 1, 2)))
+
+#define BOCHS_BREAK __asm__("xchg %bx, %bx")

inc/kern/print.h

@@ -4,7 +4,7 @@
 #include <kern/print.h>
 
 ATTR_FMT_PRINTF int
-kprintf(const char *str, ...);
+kprintf(const char *fmt, ...);
 
 int
-kvprintf(const char *str, va_list args);
+kvprintf(const char *fmt, va_list args);

kern/print.c

@@ -16,6 +16,12 @@ _printu(char *buf, uintmax num, uint base, int cap)
     char c;
 
     len = 0;
+
+    if (num == 0) {
+        buf[0] = '0';
+        return 1;
+    }
+
     while (num > 0) {
         c = dtoa(num % base);
         if (cap) {
@@ -57,6 +63,7 @@ _vprintf(const char *fmt, va_list args)
         switch (*fmt) {
             case 'p':
                 sz_ptr = 1;
+                base = 16;
                 goto pnum;
             case 'd':
                 goto pnum;
@@ -120,10 +127,11 @@ _vprintf(const char *fmt, va_list args)
                 }
 
                 len = _printu(nbuf, num, base, capf);
-                while (len) {
+
-                    arch_putc(nbuf[len]);
+                for(int i = len - 1; i >= 0; i--) {
-                    len--;
+                    arch_putc(nbuf[i]);
                 }
+
                 ret += len;
         }
     }

scripts/grub.cfg

@@ -2,5 +2,7 @@ set timeout=0
 set default=0
 
 menuentry "bond" {
-	multiboot2 bond.elf
+	multiboot2 /bond.elf
+    set gfxpayload=text
+    boot
 }

scripts/linker.lds

@@ -5,10 +5,31 @@ ENTRY(arch_init_32)
 
 SECTIONS
 {
-	. = KERNEL_IMG_VADDR + KERNEL_IMG_PADDR;
+	. = KERN_BASE_START + KERN_IMG_PADDR;
 
-	.multiboot_header ALIGN(KERNEL_PAGE_SIZE) : AT(ADDR(.multiboot_header) - KERNEL_IMG_VADDR)
+    KERN_IMG_START = .;
+
+	.multiboot_header ALIGN(0x1000) : AT(ADDR(.multiboot_header) - KERN_BASE_START)
 	{
 		*(.multiboot_header)
 	}
+
+    .text ALIGN(0x1000) : AT(ADDR(.text) - KERN_BASE_START)
+    {
+        *(.text)
+    }
+
+    .data ALIGN(0x1000) : AT(ADDR(.data) - KERN_BASE_START)
+    {
+        *(.data)
+        *(.rodata*)
+    }
+
+    .bss ALIGN(0x1000) : AT(ADDR(.bss) - KERN_BASE_START)
+    {
+        *(.bss)
+        *(COMMON)
+    }
+
+    KERN_IMG_STOP = .;
 }