Fixing a bunch of broken stuff including the looping bootloader boot.asm

.clang-format

@@ -1,5 +1,6 @@
 ---
-Language: Cpp
+Language: C
+Standard: C11 (or C17)
 BasedOnStyle: LLVM
 IndentWidth: 4
 UseTab: Never

.clang-tidy

@@ -1,12 +1,48 @@
-Checks: "clang-diagnostic-*,clang-analyzer-*,cppcoreguidelines-*,modernize-*,-modernize-use-trailing-return-type"
+Checks: "clang-diagnostic-*,clang-analyzer-*,modernize-*,-modernize-use-trailing-return-type"
 WarningsAsErrors: true
 HeaderFilterRegex: ""
 AnalyzeTemporaryDtors: false
-FormatStyle: google
+FormatStyle: llvm
 CheckOptions:
-  - key: cert-dcl16-c.NewSuffixes
-    value: "L;LL;LU;LLU"
-  - key: cert-oop54-cpp.WarnOnlyIfThisHasSuspiciousField
-    value: "0"
-  - key: cppcoreguidelines-explicit-virtual-functions.IgnoreDestructors
-    value: "1"
+  - key: modernize-use-trailing-return-type.Enabled
+    value: false
+  - key: readability-identifier-naming.NamespaceCase
+    value: CamelCase
+  - key: readability-identifier-naming.ClassCase
+    value: CamelCase
+  - key: readability-identifier-naming.StructCase
+    value: CamelCase
+  - key: readability-identifier-naming.FunctionCase
+    value: CamelCase
+  - key: readability-identifier-naming.VariableCase
+    value: camelBack
+  - key: readability-identifier-naming.ConstantCase
+    value: UPPER_CASE
+  - key: readability-identifier-naming.EnumCase
+    value: CamelCase
+  - key: readability-identifier-naming.EnumConstantCase
+    value: UPPER_CASE
+  - key: readability-identifier-naming.GlobalConstantCase
+    value: UPPER_CASE
+  - key: readability-identifier-naming.GlobalVariableCase
+    value: camelBack
+  - key: readability-identifier-naming.LocalConstantCase
+    value: camelBack
+  - key: readability-identifier-naming.LocalVariableCase
+    value: camelBack
+  - key: readability-identifier-naming.MemberConstantCase
+    value: camelBack
+  - key: readability-identifier-naming.MemberVariableCase
+    value: camelBack
+  - key: readability-identifier-naming.ParameterCase
+    value: camelBack
+  - key: readability-identifier-naming.TemplateParameterCase
+    value: camelBack
+  - key: readability-identifier-naming.TypedefCase
+    value: CamelCase
+  - key: readability-identifier-naming.TypeAliasCase
+    value: CamelCase
+  - key: readability-identifier-naming.TypeTemplateParameterCase
+    value: CamelCase
+  - key: readability-identifier-naming.VariableTemplateCase
+    value: camelBack

.gdbinit

@@ -4,6 +4,16 @@ set architecture i386
 # Set the disassembly flavor
 set disassembly-flavor intel
 
+set disassemble-next-line
+
+set pagination enable
+
+set print address
+
+set logging enable
+
+set logging file gdb.log
+
 # Set the prompt
 set prompt (gdb)
 
@@ -16,10 +26,10 @@ set history size 1000
 set solib-search-path .
 
 # Set the default directory
-cd /path/to/project
+d /home/user/Documents/ClassicOS
 
 # Set the default target
-file kernel
+file ClassicOS/build/kernel
 
 # Set the symbol file
 symbol-file kernel

CMakeLists.txt

@@ -71,7 +71,10 @@ set(CMAKE_EXE_LINKER_FLAGS "-g -s")
 set(CMAKE_LINK_FLAGS "${CMAKE_LINK_FLAGS} -e kernel_main")
 set(CMAKE_CXX_FLAGS "-g -Wall")
 set(CMAKE_C_FLAGS "-g -Wall -m32")
+set(CMAKE_C_FLAGS_DEBUG "-g")
 set(CMAKE_BUILD_TYPE Debug)
+set(CMAKE_GDB_COMMAND gdb)
+set(CMAKE_CXX_FLAGS_DEBUG "-g -O0")
 set(CMAKE_CXX_COMPILER g++)
 set(CMAKE_ASM_COMPILER nasm)
 set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} --32")

ask.txt

@@ -147,16 +147,23 @@ target_link_libraries(ClassicOS PRIVATE)
 
 set(CMAKE_C_COMPILER gcc)
 set(CMAKE_LINKER ld)
-set(CMAKE_EXE_LINKER_FLAGS "-g")
+set(CMAKE_EXE_LINKER_FLAGS "-g -s")
+set(CMAKE_LINK_FLAGS "${CMAKE_LINK_FLAGS} -e kernel_main")
 set(CMAKE_CXX_FLAGS "-g -Wall")
-set(CMAKE_C_FLAGS "-g -Wall")
+set(CMAKE_C_FLAGS "-g -Wall -m32")
+set(CMAKE_C_FLAGS_DEBUG "-g")
 set(CMAKE_BUILD_TYPE Debug)
+set(CMAKE_GDB_COMMAND gdb)
+set(CMAKE_CXX_FLAGS_DEBUG "-g -O0")
 set(CMAKE_CXX_COMPILER g++)
 set(CMAKE_ASM_COMPILER nasm)
+set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} --32")
 set(CMAKE_SYSTEM_PROCESSOR i386)
+set(CMAKE_SYSTEM_NAME None)
 set(CMAKE_ASM_NASM_COMPILER nasm)
 set(CMAKE_C_STANDARD 17)
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/src)
 set(CMAKE_BINARY_DIR ${CMAKE_CURRENT_SOURCE_DIR}/build)
 set_target_properties(ClassicOS PROPERTIES LINK_FLAGS "-T ${CMAKE_CURRENT_SOURCE_DIR}/linker.ld")
+

src/boot/boot.asm

@@ -1,61 +1,110 @@
 ; Set up the segment registers
-   xor ax, ax
-   mov ds, ax
-   mov es, ax
+xor ax, ax
+mov ds, ax
+mov es, ax
 
-   ; Set up stack and jump to main
-   mov ss, ax
-   mov sp, 0x7c00
-   jmp main
+; Set up stack and jump to main
+mov ss, ax
+mov sp, 0x7c00
+jmp main
 
-   ; Print 'Booting ClassicOS!' to the screen
-   print:
-       mov si, message
-       mov ah, 0x0e
-   .loop:
-       lodsb
-       test al, al
-       jz .done
-       int 0x10
-       jmp .loop
-   .done:
-       ret
+; Print 'Booting ClassicOS!' to the screen
+print:
+   mov si, message
+   mov ah, 0x0e
+.loop:
+   lodsb
+   test al, al
+   jz .done
+   int 0x10
+   jmp .loop
+.done:
+   ret
 
-   ; Set the video mode to a 40 column text mode
-   set_video_mode:
-       mov ax, 0x0003    ; Set up a 80x25 text mode
-       int 0x10
+; Set the video mode to a 40 column text mode
+set_video_mode:
+   mov ax, 0x0003    ; Set up a 80x25 text mode
+   int 0x10
 
-       ; Set the number of columns to 40
-       mov ax, 0x1112
-       mov bx, 0x0007
-       int 0x10
+   ; Set the number of columns to 40
+   mov ax, 0x1112
+   mov bx, 0x0007
+   int 0x10
 
-       ret
+   ret
 
-   ; Bootloader entry point
-   main:
-       ; Call the set_video_mode function
-       call set_video_mode
+; Detect floppy disk drive
+detect_disk:
+   mov ah, 0x08
+   int 0x13
+   cmp ah, 0
+   jne .error
+   ret
 
-       ; Clear the screen
-       mov ah, 0x06
-       mov al, 0
-       xor bx, bx
-       xor cx, cx
-       mov dh, 24
-       mov dl, 39
-       int 0x10
+.error:
+   ; Handle disk detection error
+   ; Display error message or take appropriate action
+   ret
 
-       ; Call the print function
-       call print
+; Read sectors from floppy disk
+read_sectors:
+   mov ah, 0x02
+   mov al, 1  ; Number of sectors to read
+   mov ch, 0  ; Cylinder/Track number
+   mov cl, 2  ; Sector number (starting from 1)
+   mov dh, 0  ; Head number
+   mov dl, 0  ; Drive number (0 for floppy disk)
 
-       ; Infinite loop
-   .loop:
-       jmp .loop
+   mov bx, buffer  ; Destination buffer
+   mov es, bx
+   xor bx, bx
 
-   ; Message to print
-   message db 'Booting ClassicOS!', 0
+   int 0x13
 
-   times 510-($-$$) db 0
-   dw 0xaa55
+   jc .error  ; Check carry flag for error
+   ret
+
+.error:
+   ; Handle read error
+   ; Display error message or take appropriate action
+   ret
+
+; Bootloader entry point
+main:
+   ; Call the set_video_mode function
+   call set_video_mode
+
+   ; Clear the screen
+   mov ah, 0x06
+   mov al, 0
+   xor bx, bx
+   xor cx, cx
+   mov dh, 24
+   mov dl, 39
+   int 0x10
+
+   ; Call the print function
+   call print
+
+   ; Wait for a key press to exit the loop
+   mov ah, 0x00
+   int 0x16
+   
+   ; Call the detect_disk function
+   call detect_disk
+
+   ; Call the read_sectors function
+   call read_sectors
+
+   ; Infinite loop
+.loop:
+   jmp .loop
+
+; Message to print
+message db 'Booting ClassicOS!', 0
+
+; Buffer to store read sectors
+buffer times 512 db 0
+
+times 510-($-$$) db 0
+dw 0xaa55

src/boot/linker.ld

@@ -1,8 +1,34 @@
-ENTRY(boot)
-     SECTIONS {
-       . = 0x7c00;
-       .text : {
-         *(.text)
-       }
-       /* Add other sections as needed */
-     }
+ENTRY(start)
+SECTIONS {
+    . = 0x7c00;
+
+    .text : {
+        *(.text)
+    }
+
+    .data : {
+        *(.data)
+    }
+
+    .bss : {
+        *(.bss)
+    }
+
+    /* Define the bootloader signature at the end of the bootloader */
+    bootloader_signature : {
+        *(.bootloader_signature)
+    }
+
+    /* Define the bootloader magic number at the end of the bootloader */
+    bootloader_magic : {
+        *(.bootloader_magic)
+    }
+
+    /* Define the bootloader padding to fill up the remaining space */
+    bootloader_padding : {
+        *(.bootloader_padding)
+    }
+
+    /* Set the bootloader size to 512 bytes */
+    = 512;
+}

src/kernel/arch/x86/gdt.c

@@ -80,7 +80,7 @@ void gdt_init()
 }
 
 // Exception handlers
-extern void divide_error();
+extern void divide_error(struct idt_regs *regs);
 extern void page_fault(struct idt_regs *regs);
 extern void general_protection_fault();
 extern void double_fault();
@@ -92,20 +92,20 @@ extern void keyboard();
 extern void device();
 
 // Register an ISR
-void isr_register(uint8_t num, void (*handler)(struct idt_regs *))
+void isr_register(uint8_t num, void (*handler)(struct isr_regs *))
 {
     isr_table[num] = handler;
 }
 
+void divide_error(struct idt_regs *regs)
+{
+    printf("Divide by zero error!\n");
+    // Additional actions can be taken as needed
+}
+
 // Initialize the ISR
 void isr_init()
 {
-    // Initialize ISR table
-    for (int i = 0; i < ISR_TABLE_SIZE; i++)
-    {
-        isr_table[i] = NULL;
-    }
-
     // Register exception handlers
     isr_register(0, divide_error);
     isr_register(PAGE_FAULT, page_fault);

src/kernel/arch/x86/idt.h

@@ -2,7 +2,7 @@
 #define IDT_H
 
 #include <stdint.h>
-
+#include "isr.h"
 // IDT entry structure
 struct idt_entry
 {
@@ -21,7 +21,7 @@ struct idt_ptr
 } __attribute__((packed));
 
 // Exception handlers
-void divide_error();
+void divide_error(struct idt_regs *regs);
 void double_fault();
 
 // Interrupt handlers

src/kernel/arch/x86/isr.c

@@ -18,7 +18,7 @@ void dummy_isr(struct isr_regs *regs)
 }
 
 // ISR table
-extern void (*isr_table[256])(struct isr_regs *regs);
+void (*isr_table[256])(struct isr_regs *regs) = {0};
 
 // Register an ISR
 extern void isr_register(uint8_t num, void (*handler)(struct isr_regs *regs))
@@ -32,7 +32,7 @@ void isr_handler(struct idt_regs *regs)
     switch (regs->int_no)
     {
     case 0x00:
-        divide_error();
+        divide_error(regs);
         break;
     case 0x06:
         invalid_opcode();
@@ -74,7 +74,7 @@ void isr_handler(struct idt_regs *regs)
 }
 
 // Exception handlers
-void divide_error()
+void divide_error(struct idt_regs *regs)
 {
     printf("Divide by zero error!\n");
     // Additional actions can be taken as needed

src/kernel/arch/x86/isr.h

@@ -3,6 +3,8 @@
 
 #include <stdint.h>
 
+extern void (*isr_table[256])(struct isr_regs *regs);
+
 struct isr_regs
 {
     uint32_t gs, fs, es, ds;     // Segment selectors