0.619s-boot: load 180KB to 0x8000

LINES

@@ -18,3 +18,5 @@
 
 2021-2-23 0.556: 556 lines, 6 files, rain
 
+2021-2-25 0.619: 619 lines, 6 files, rain
+

README.md

-<pre>
-
 Cunix kernel
 ============
 
 # Versions
 `0.362s-boot`:  
-&#9`Boot` read `loader` from `boot-device`, then it jumps to it.  
-&#9Loader doesn't load anything, it just enable long-mode and paging.  
-&#9Loader defines temporary page table at `0x70000` (0x0000:0x7000),  
-&#9it uses `2MB` page to make 0-12 MB memory to `0x0000 - 0xc0000`.  
+&nbsp;&nbsp;&nbsp;&nbsp;`Boot` read `loader` from `boot-device`, then it jumps to it.  
+&nbsp;&nbsp;&nbsp;&nbsp;Loader doesn't load anything, it just enable long-mode and paging.  
+&nbsp;&nbsp;&nbsp;&nbsp;Loader defines temporary page table at `0x70000` (0x0000:0x7000),  
+&nbsp;&nbsp;&nbsp;&nbsp;it uses `2MB` page to make 0-12 MB memory to `0x0000 - 0xc0000`.  
 
 
 `0.385s-boot`:  
-&#9rebuild `boot` and `loader`.  
+&nbsp;&nbsp;&nbsp;&nbsp;rebuild `boot` and `loader`.  
 
 
 `0.391s-boot`:  
-&#9loader` forgot open A20 line, so `0.385` and `0.362` just can
-&#9use 1MB memory like real-mode.  
+&nbsp;&nbsp;&nbsp;&nbsp;loader` forgot open A20 line, so `0.385` and `0.362` just can
+&nbsp;&nbsp;&nbsp;&nbsp;use 1MB memory like real-mode.  
 
 
 `0.432s-boot`:  
-&#9make directory `include/`, and add segment.inc, but it doesn't work. :-)  
+&nbsp;&nbsp;&nbsp;&nbsp;make directory `include/`, and add segment.inc, but it doesn't work. :-)  
 
 
 `0.451s-boot`:  
-&#9`boot` can load 8 sectors (4KB) of loader (not 1 sector).  
+&nbsp;&nbsp;&nbsp;&nbsp;`boot` can load 8 sectors (4KB) of loader (not 1 sector).  
 
 
 `0.466s-boot`:  
-&#9rebuild `boot`
+&nbsp;&nbsp;&nbsp;&nbsp;rebuild `boot`
 
 
 `0.487s-boot`:  
-&#9`loader` let FS can access 4GB memory in real-mode. because 
-&#9`loader` loaded GDT and load a data-segment to fs, then disable
-&#9protect-mode. 
+&nbsp;&nbsp;&nbsp;&nbsp;`loader` let FS can access 4GB memory in real-mode. because 
+&nbsp;&nbsp;&nbsp;&nbsp;`loader` loaded GDT and load a data-segment to fs, then disable
+&nbsp;&nbsp;&nbsp;&nbsp;protect-mode. 
 
 
 `0.484s-boot`:
-&#9let `readdisk.inc` smaller, but we just can use CHS or LBA, not both. 
+&nbsp;&nbsp;&nbsp;&nbsp;let `readdisk.inc` smaller, but we just can use CHS or LBA, not both. 
 
 
 `0.509s-kernel`: 
-&#9load kernel to 0x8200-0x9200 for 4KB, kernel.asm display 'K' to screen. 
+&nbsp;&nbsp;&nbsp;&nbsp;load kernel to 0x8200-0x9200 for 4KB, kernel.asm display 'K' to screen. 
 
 `0.556s-int`: 
-&#9init IDT at 0x0000-0x1000, and set all handler at ignore_int, but it do nothing. 
-
-</pre>
-
+&nbsp;&nbsp;&nbsp;&nbsp;init IDT at 0x0000-0x1000, and set all handler at ignore_int, but it do nothing.
 
+`0.619s-boot`: 
+&nbsp;&nbsp;&nbsp;&nbsp;load 180KB of disk, not 4KB. 

boot/x86/boot.asm

@@ -17,6 +17,8 @@
 
 
 
+CYLINDERS_NEED equ 10
+
 org 0x7c00
 
 _start:
@@ -38,7 +40,7 @@ _start:
 	mov si, message
 	call print
 
-	call load_loader
+	call read_it
 
 	jmp 0x0000:0x8000
 
@@ -67,28 +69,89 @@ print:
 	ret
 
 
-load_loader:
-	mov cl, 0x02
-	mov bx, 0x8000
+read_it:
+	; segment address of loader+kernel
+	mov ax, 0x0800
+	mov es, ax
 
-	mov di, diskpanic_message
+	; cylinder 0
+	mov ch, 0
+	; header 0
+	mov dh, 0
+	; start sector 2
+	mov cl, 2
 
 .read_loop:
-	call read_sector
-	jc panic
+	; I know it use to save source-address, but there isn't another 
+	; register free. 
 
-; read 9 sectors (1 loader, 8 kernel)
-	add cl, 0x01
-	add bx, 0x0200
+	; error counts
+	mov si, 0
 
-	cmp cl, 0x0a
-	je .ret
+.retry:
+	mov ah, 0x02
+	; one sector
+	mov al, 1
 
-	jmp .read_loop
+	; offset 0x0000
+	mov bx, 0
 
-.ret:
-	ret
+	; boot device
+	mov dl, [BI_BOOTDEV]
+
+	; call -> BIOS
+	int 0x13
+
+	; if error
+	jnc .cont_read
+	
+.error:
+	add si, 1
+	; we try it for 5 times
+	mov di, diskpanic_message
+
+	cmp si, 5
+	jae panic
+
+.reset_disk:
+	mov ah, 0x00
+	mov dl, [BI_BOOTDEV]
+
+	int 0x13
+
+	; and retry
+
+	jmp .retry
+
+.cont_read:
+	; add for 0x0020 (not 0x0200)
+	mov ax, es
+	add ax, 0x0020
+	mov es, ax
+
+	; we've been read one sector
+	add cl, 1
+
+	; if read done
+SECTORS_1_TRACK equ 18
+	cmp cl, SECTORS_1_TRACK
+	jbe .read_loop
+
+.update_track:
+	mov cl, 1
+	add dh, 1
+HEADS_1_CYLINDER equ 2
+	cmp dh, HEADS_1_CYLINDER
 	
+	jb .read_loop
+
+.update_head
+	mov dh, 0
+	add ch, 1
+	cmp ch, CYLINDERS_NEED
+	jb .read_loop
+
+	ret
 
 panic:
 	mov si, panic_message