reorg done

diff --git a/.gitignore b/.gitignore
index a3492c9..8a10a5b 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,4 @@
 dis1
 dis2
 *.log
-bootldr
+86kern

diff --git a/kern/Makefile b/kern/Makefile
index 44d9d66..70e479b 100644 (file)
--- a/kern/Makefile
+++ b/kern/Makefile
@@ -1,27 +1,38 @@
+csrc = $(wildcard src/*.c)
+ssrc = $(wildcard src/*.asm)
+obj = $(csrc:.c=.o) $(ssrc:.asm=.o)
+dep = $(csrc:.c=.d)
+
 disk_numsec = 720
 #disk_numsec = 2880
 
-bin = bootldr
-img = bootldr.img
+bin = 86kern
+img = 86kern.img
 
 CC = ia16-elf-gcc
 LD = ia16-elf-ld
 
-CFLAGS = -march=i8088 -mtune=i8088
+CFLAGS = -march=i8088 -mtune=i8088 -MMD
 
 $(img): $(bin)
        dd if=/dev/zero of=$@ bs=512 count=$(disk_numsec)
        dd if=$< of=$@ bs=512 conv=notrunc
 
-$(bin): boot/boot.o boot/boot2.o boot/main.o
-       $(LD) -T boot.ld -Map boot.map -o $@ $^
+$(bin): $(obj)
+       $(LD) -T kern.ld -Map kern.map -o $@ $(obj)
+
+-include $(dep)
 
 %.o: %.asm
        nasm -o $@ -f elf $<
 
 .PHONY: clean
 clean:
-       rm -f boot/*.o $(bin)
+       rm -f $(obj) $(bin)
+
+.PHONY: cleandep
+cleandep:
+       rm -f $(dep)
 
 
 .PHONY: run
@@ -35,4 +46,4 @@ debug: $(img)
 .PHONY: disasm
 disasm: $(bin)
        ndisasm -o 0x7c00 $< >dis1
-       ndisasm -o 0x80000 -e 512 $< >dis2
+       ndisasm -o 0x98000 -e 512 $< >dis2

diff --git a/kern/kern.ld b/kern/kern.ld
index 99bc701..3922811 100644 (file)
--- a/kern/kern.ld
+++ b/kern/kern.ld
@@ -8,10 +8,12 @@ SECTIONS {
        }
        _bootsect_end = .;
 
-       /* load high out of the way, to allow stage2 to load the kernel low */
-       . = 0x80000;
-       _stage2_start = .;
-       _stage2_start_seg = _stage2_start >> 4;
+       /* load high out of the way, to leave the rest of RAM for userland
+        * reserving the top 32kb for the kernel for now
+        */
+       . = 0x98000;
+       _kern_start = .;
+       _kern_start_seg = _kern_start >> 4;
        .text : AT(_bootsect_end) {
                * (.startup);
                * (.text*);
@@ -22,13 +24,13 @@ SECTIONS {
        }
        .bss ALIGN(4) (NOLOAD): {
                _bss_start = .;
-               _bss_start_off = _bss_start - _stage2_start;
+               _bss_start_off = _bss_start - _kern_start;
                * (.bss*);
                * (COMMON);
                . = ALIGN(4);
        }
        _bss_size = SIZEOF(.bss);
        . = ALIGN(4);
-       _stage2_end = .;
-       _stage2_size = _stage2_end - _stage2_start;
+       _kern_end = .;
+       _kern_size = _kern_end - _kern_start;
 };

diff --git a/kern/src/boot.asm b/kern/src/boot.asm
index 96506de..5be618b 100644 (file)
--- a/kern/src/boot.asm
+++ b/kern/src/boot.asm
@@ -3,8 +3,8 @@
        bits 16
        section .bootsect
 
-extern _stage2_start_seg
-extern _stage2_size
+extern _kern_start_seg
+extern _kern_size
 
 boot_driveno   equ 7b00h
 num_read_tries equ 7b06h       ; 2 bytes
@@ -57,7 +57,7 @@ bios_param_block:
        db 0            ; 25h: winnt flags
        db 28h          ; 26h: signature(?)
        dd 0            ; 27h: volume serial number
-       db "80 SIX BOOT"; 2bh: volume label, 11 bytes
+       db "86BOOT     "; 2bh: volume label, 11 bytes
        db "FAT12   "   ; 36h: filesystem id, 8 bytes
 
 start:
@@ -65,12 +65,10 @@ start:
        xor ax, ax
        mov ds, ax
        mov es, ax
+       mov ss, ax
        jmp 00:.setcs
 .setcs:
-       ; put the stack high
-       mov ax, 0x7f00
-       mov ss, ax
-       xor sp, sp
+       mov sp, 0x7b00  ; temp stack below our vars
        mov [boot_driveno], dl
 
        ; query sectors per track
@@ -92,13 +90,13 @@ start:
 .querydone:
 
        ; load the rest of the code high
-       mov ax, _stage2_size
+       mov ax, _kern_size
        add ax, 511
        mov cl, 9
        shr ax, cl
        inc ax
        mov [sect_pending], ax
-       mov ax, _stage2_start_seg
+       mov ax, _kern_start_seg
        mov es, ax      ; destination segment
        mov word [destptr], 0
        mov word [start_sect], 1        ; start from sector 1 to skip boot sector
@@ -173,7 +171,7 @@ start:
        jnz .rdloop
 
        ; loaded sucessfully, load segment registers and jump
-.done: mov ax, _stage2_start_seg
+.done: mov ax, _kern_start_seg
        mov ds, ax
        mov es, ax
        push ax
@@ -248,7 +246,7 @@ print_hex_digit:
 
 str_rdtrack2   db " from ",0
 str_rdtrack3   db "/",0
-str_load_fail  db "Failed to load 2nd stage!",0
+str_load_fail  db "Failed to load kernel!",0
 str_newline    db 13,10,0
 
        times 510-($-$$) db 0

diff --git a/kern/src/main.c b/kern/src/main.c
index 7110581..1ca879b 100644 (file)
--- a/kern/src/main.c
+++ b/kern/src/main.c
@@ -1,4 +1,4 @@
-void bootmain(void)
+void kmain(void)
 {
        int i, j;
        unsigned short __far *vmem = (void __far*)0xb8000000ul;

diff --git a/kern/src/startup.asm b/kern/src/startup.asm
index c90cef6..c64684a 100644 (file)
--- a/kern/src/startup.asm
+++ b/kern/src/startup.asm
@@ -3,8 +3,10 @@
        bits 16
        section .startup
 
-extern bootmain
-extern _stage2_start_seg
+; memory reserved at the top of RAM for the kernel stack
+STACKSZ equ 4096
+
+extern kmain
 extern _bss_start_off
 extern _bss_size
 
@@ -12,6 +14,11 @@ global _start
 _start:
        ; TODO floppy off if necessary
 
+       ; move stack to the top of RAM (TODO: detect and avoid Ext. BIOS data area)
+       mov ax, (0xa0000 - STACKSZ) >> 4
+       mov ss, ax
+       mov sp, STACKSZ
+
        ; zero .bss
        mov di, _bss_start_off
        mov cx, _bss_size
@@ -20,7 +27,7 @@ _start:
        xor ax, ax
        mov es, ax
 
-       call bootmain
+       call kmain
 
 hang:  hlt
        jmp hang