From 5d787348b1a90e649226b41d17a1a9ab244da4b4 Mon Sep 17 00:00:00 2001
From: Tom-on64 <kubecekt@gmail.com>
Date: Fri, 22 Dec 2023 13:18:07 +0100
Subject: [PATCH] Added file loading

---
 .gitignore                   |   1 +
 build.sh                     |   5 +-
 build/boot.bin               | Bin 512 -> 512 bytes
 build/bootloader.bin         | Bin 1024 -> 1024 bytes
 build/{main.bin => calc.bin} | Bin 512 -> 512 bytes
 build/filetable.bin          | Bin 512 -> 512 bytes
 build/kernel.bin             | Bin 1024 -> 1024 bytes
 build/os.bin                 | Bin 2048 -> 2560 bytes
 src/boot.asm                 |  34 ++++++++--
 src/calc.asm                 |  13 ++++
 src/filetable.asm            |   2 +-
 src/kernel.asm               | 117 ++++++++++++++++++++++++++++++-----
 src/print.asm                |   4 ++
 13 files changed, 153 insertions(+), 23 deletions(-)
 create mode 100644 .gitignore
 rename build/{main.bin => calc.bin} (62%)
 create mode 100644 src/calc.asm

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5963eec
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+./build/**
\ No newline at end of file
diff --git a/build.sh b/build.sh
index 43b5eaa..5bf4925 100644
--- a/build.sh
+++ b/build.sh
@@ -1,13 +1,14 @@
 # Bootloader
 nasm -fbin src/boot.asm -o build/boot.bin
 nasm -fbin src/filetable.asm -o build/filetable.bin
-cat build/main.bin build/filetable.bin > build/bootloader.bin
+cat build/boot.bin build/filetable.bin > build/bootloader.bin
 
 # Kernel
 nasm -fbin src/kernel.asm -o build/kernel.bin
 
 # Final binary
-cat build/bootloader.bin build/kernel.bin > build/os.bin
+nasm -fbin src/calc.asm -o build/calc.bin
+cat build/bootloader.bin build/kernel.bin build/calc.bin > build/os.bin
 
 # Run QEMU
 qemu-system-x86_64 -drive format=raw,file="./build/os.bin",index=0,media=disk -m 256M
diff --git a/build/boot.bin b/build/boot.bin
index 05aa27c933972ece09a581dce288956341c92b3b..2f731e97fad30bd89594df69547ca144e0e29e3e 100644
GIT binary patch
literal 512
zcmXp!(08Ek#$JY+&Nm%mdusOWt$7j0&;?|@$Yj{Jv*tx0!)^wFzQcyMw=ivB1c`5D
z*v7Dt>8x;(!EOcxs00&Sf*B|wz5^(618D4nz88HLy5#oM1ixZnU{KiisOAL|!>=z1
zTlhBfZ)aG;aiE0dtibE<iH8#mPd5K#DUt2G(ENbE`G7(556e2{<^$}zx7TQ%?qEN7
zipBBuy?vW%UL5|Pc-WxA00<bkco~4$DL=m?GcR2sJGCfJ55Y|<%Fk6uDatHMRbX(*
WEY4PNEh@?{QUvK41xO(fx(Wa|m1uzg

literal 512
zcmXp!(08Ek#$JXAoo{wC2=pB`yuF2K1LIbPZ44Wk&I%W)?`BYd3NnEOnSp{rJAi^W
cfchTvz398}ih+Sa;nx=+ISPha2!yTz06Li>b^rhX

diff --git a/build/bootloader.bin b/build/bootloader.bin
index 84b1ac78a402331d065b4bd7a4302e8a81213750..c59d0840d3c9128562cc098c01a1b007659f37dc 100644
GIT binary patch
literal 1024
zcmXp!(08Ek#$JY+&Nm%mdusOWt$7j0&;?|@$Yj{Jv*tx0!)^wFzQcyMw=ivB1c`5D
z*v7Dt>8x;(!EOcxs00&Sf*B|wz5^(618D4nz88HLy5#oM1ixZnU{KiisOAL|!>=z1
zTlhBfZ)aG;aiE0dtibE<iH8#mPd5K#DUt2G(ENbE`G7(556e2{<^$}zx7TQ%?qEN7
zipBBuy?vW%UL5|Pc-WxA00<bkco~4$DL=m?GcR2sJGCfJ55Y|<%Fk6uDatHMRbX(*
zEY4PNEh@?{QUvK41xO(fx~du!a;Z6bNtt<82F5zci8;wu2Btd6`T02^8NiUWGBB$}
L(lE*#W+4Co67h7;

delta 98
zcmZqRXyEWPJkWQb@5Ww+37v0tGYIq@HoU!sX#?X{hHVTRna&Cqsqbb`KoMjH3JUE2
p3f=(fd(iiy@4_nv1_p&+Up5;uZDpMNk5PrmycWnl&p3&Z7XUkaDJ=j1

diff --git a/build/main.bin b/build/calc.bin
similarity index 62%
rename from build/main.bin
rename to build/calc.bin
index 2985e5aaa256aa6a62b189e82c73e11d58a13ed8..961601fde918b629e7915d8875d7a91156a35f57 100644
GIT binary patch
literal 512
zcmdlN$nb)R;n$ahEqt5#w==BaI8efJR^avb#KQ@OC!2q=l*o2oXnw%oe88ajhh-ge
z^8xnVJ`9?tJJ=7NVsU(ZZ=XBEi^KmD4;xe%009FRFM~&FPENiekTD8|LI?l=Hv}dd

literal 512
zcmXp!(08Ek#$JXAoo{wC2=pB`yuF2K1LIbPZ44Wk&I%W)?`BXy5o87m3he+2-T>-*
Z(D$P6!Yc*_28CZ=faE9`Y9SE13II66B6R=&

diff --git a/build/filetable.bin b/build/filetable.bin
index 1688beac51b52efa4bb29471f62b8abd05c81c2b..ba34b58892bcff3e1056e34cdb2fa755b83fcaad 100644
GIT binary patch
delta 16
XcmZo*X<(V4#AH^x(eOOuL<e2~DdYtJ

delta 16
XcmZo*X<(V4#AIH((eOOuL<e2~DeVOT

diff --git a/build/kernel.bin b/build/kernel.bin
index a9c02b9ec6e06fbfd5e89819d0a6067375d955f0..2798d28112fa4038d5132ba14cb9ed66f71a1e3f 100644
GIT binary patch
delta 438
zcmZqRXyB;t5PQk^;soQqSBx(z8TWl*d{NA}|16W?Ny7tY#kTNmXE-Zh!&}1M!TRr@
z`|H;mxXub3V`b>zJHxc#ER&4~f6G1w8#n%zgA6wA{4M_&Y=Zb(^g#M|GYIq@HoUFY
z#coquqG`oi!tDI|Q*akhA5h5IinWyQ-^mhY_tzimK}xJj1b}*?onK$r_nq;@XNH&M
z|2J|O9B@|a5_fL+rBfo)@XMfvui=+vJ!iu!gKrNRF1&uSkCW-eNrsoc|2qzDVdw&S
z;;is)h6a$OTbMxH7yB4CFm7eo#&A}+m~)>j(~CI_FBSgp04llBccAY<-;2HruNW8@
zcpLVWFuiDGc***IpDokGYy+V)j4#|6USHh@r0p199{TrU(!{l@{J`MhX8?uCi$I2#
zJ^v;?G>|>TsCl}B{opAU$Jh7v9c6rR_<!PIg9-y6VBq4Ntj#DLz>u9<l&8nV%f-uJ
zr@-KrnUkuJmtUfgmS38eq6icWPE9V!FG3Y_O9U!QQ7F#<sm{qyOv%hkS12gTPcKT$
K-JHUBoDl%}GPa}u

delta 250
zcmZqRXyB-Sp~<+<jq$}@hJ68yFRnA}|IT=f?FS=+;eoSaTlls!oE5O)En)3ob$|VK
z1J_xBW2_7dzBAf*lxWzvmFU>Gmt@-n@wd!o*zuilH-kXmVZ+;<_dl&G;n)|(_@ay9
z_3GCv_swT~(ZKL};l2#U7ZnUpMTRGx)w<YiYD<(S%QMOd1v9>IV|aaaACR_Vcp3Nq
zMgL@9Mpb^Gv-rUddEv+KQse*RMn(fEEk@1L9qb2Bu{gfIw@;Pv#o_;nhYczWfMD`D
tMrpb1)S^5+E?zEP20H}?AnBHwld6!HU!stfUz(S)*^=ov<KzcSR{@4*V~79%

diff --git a/build/os.bin b/build/os.bin
index 9c1f7d49d5a56add76c5996628d5f063d522eb47..87de98b511eeaa134101af9d86538695e91d1dcf 100644
GIT binary patch
delta 727
zcmY+CPiPZC6vp3dcTF2eHdsjyT3tZ{rBXH*!4L}?O?pr;_9%$Kq%}0n%64lNwq%7I
zVvro%s|Rmh6j~c?CGD6P{FB;+TnYt6tcc8Zy;zGv4vDih)OKK)dGCF1cznOnJlcVb
zzg#F6)|NoM_ao<BRPmBZu0o#PND}Z%l|-Qgo<i0CvB=CIJO3PBz${~Q%VG(Hc7fR`
zbkIW20xhi3XTKCkp`Jgys19!cfPlZMgn`D^wW52DpNA)%Wrfu@*(1?;weLgDQCVis
zSfBATl~h}?s(4$Z3!E;X`>Z4>$@Hi&mXOl}|HBbk8W-Yn@>W8CbIFM@;k+zM@=>R2
zHp(NtiH<QRr{~bVPbib~nuxqdcmt6;2yY=WfnFJmzveF+-lBUR3{TLdIC5OG60xiq
zr{Q_aLC(FxJTjQz5TC^m4D;Cv1S5R53Bk*JcEIj$JLAhcg40T0fKxg`*5+`Y_R&-*
zz)iZFHKikB{mj^sfa0M&S3*`D|3Tyzm{YA;r&td8@;xD~aY8wyHAK~|HBM!^v<>n1
zI@GOixQih*FfX=pl_I5LBBQ$m+CSIrkYJcWHW8zHq6_yj<RO?sYk^93{I{)lX;@*%
zT`;*8KF#Q3thj##kuX@Rn4W`RzHX8S`cw8ePYvS1c7=jB?>F^zR_t9yyYRe0d-3S~
z+`&uG2198L3J^}F5<*&1gb`^n9j7>8IB{K(<h{9YjLPD|)D2sml45Zi@J(47m1E;`
jaqb=J#8KG(FZy@3-**9a4H1F8L%>iXm6Eo>KSqB6js7cj

delta 343
zcmZn=X%O%<JkWQb@5Ww+37v0tGYIq@HoU!sX#?X{hHVTRna&Cqsqbb`KoMjH3JUE2
z3f=(fd(iiy@4_nv1_p&+Up5;uZDpMNk5PrmycWnl&p3&ZxBi7D<32aW7k3%<1u(w2
z&anSG<1w}$j0}bc&Wdf}+s<%Sz=pSkwS(3D_1g_xX9bS2GA#JcXyZ|$VdGY!W8+?u
zZ4<=bGMiz?cSfk&I`4m4SHiI`jPXSm!|T<rSMHn7_@aT~^}>A_j4vt}po$DnI;(ZD
z+tijQPnKtu5ejB};l}X#>OLTC$M7=l|BL>~zO1VJKxgrT9rD7D;ibm^$&IWAQd*3f
zr#sjWo?>x)eQ%#C<BP-p6Av3y7y!ZKbF9*G*{MZ&dR)9*ybN{<3_#K?GbdFcFTX?~
REx$A`WwRyQaiFKK0s!9*is}FW

diff --git a/src/boot.asm b/src/boot.asm
index 5943c7f..d07d211 100644
--- a/src/boot.asm
+++ b/src/boot.asm
@@ -7,16 +7,29 @@ start:
     xor ax, ax
     mov es, ax
     mov ds, ax
-    mov bp, 0x9000
+    mov bp, 0x7c00
     mov sp, bp
 
+    ; Save drive number
+    mov byte [driveNumber], dl
+
+    ; Print boot message
+    mov si, bootMsg
+    call print
+    mov dl, byte [driveNumber]
+    call printHex
+    mov si, newline
+    call print
+
     ; Read filetable from disk
     mov bx, FILETAB_LOC ; Filetable location in memory
     mov es, bx
     xor bx, bx
 
     mov ah, 2           ; Read from disk
-    mov al, 1           ; Read 1 sector
+    mov al, 1           ; Read 1 sector (512B)
+
+    mov dl, byte [driveNumber] ; Drive number
     mov ch, 0           ; Cylinder
     mov dh, 0           ; Head
     mov cl, 2           ; Sector
@@ -30,7 +43,9 @@ start:
     xor bx, bx
 
     mov ah, 2           ; Read from disk
-    mov al, 2           ; Read 2 sectors
+    mov al, 2           ; Read 2 sectors (1024B)
+
+    mov dl, byte [driveNumber] ; Drive number
     mov ch, 0           ; Cylinder
     mov dh, 0           ; Head
     mov cl, 3           ; Sector
@@ -46,13 +61,24 @@ start:
     mov gs, ax
     mov ss, ax
 
+    mov bl, byte [driveNumber]
+
     ; Far jump to the kernel
-    jmp KERNEL_LOC:0x0
+    jmp KERNEL_LOC:0x0000
 
 readFail:
+    mov si, diskErrorMsg
+    call print
     cli
     hlt
 
+%include "./src/print.asm"
+
+driveNumber: db 0
+
+bootMsg: db ENDL, "Booting kern.", ENDL, "Booting from drive ", 0
+diskErrorMsg: db "Disk Error!", ENDL, 0
+
 FILETAB_LOC equ 0x1000
 KERNEL_LOC equ 0x2000
 
diff --git a/src/calc.asm b/src/calc.asm
new file mode 100644
index 0000000..a225265
--- /dev/null
+++ b/src/calc.asm
@@ -0,0 +1,13 @@
+[bits 16]
+
+start:
+    mov si, msg
+    call print
+    cli
+    hlt
+
+%include "./src/print.asm"
+
+msg: db "Hello!", ENDL, 0
+
+times 512-($-$$) db 0
diff --git a/src/filetable.asm b/src/filetable.asm
index 9c2b7e9..d61be41 100644
--- a/src/filetable.asm
+++ b/src/filetable.asm
@@ -2,7 +2,7 @@
 db "{"  ; Start
 db "kernel.bin:03,"
 db "calc:05,"
-db "coolThing:07"
+db "coolThing:06"
 db "}"  ; End
 
 times 512-($-$$) db 0
diff --git a/src/kernel.asm b/src/kernel.asm
index 0447668..c3b309b 100644
--- a/src/kernel.asm
+++ b/src/kernel.asm
@@ -1,8 +1,9 @@
 [bits 16]
 
-%define ENDL 0x0a, 0x0d
-
 start:
+    ; Save the drive number from stack
+    mov byte [driveNumber], dl
+
     call resetTextMode
 
     ; Print start message
@@ -14,7 +15,7 @@ input:
     mov si, prompt
     call print
     mov di, userInput
-    mov byte [inputLen], 0
+    xor cx, cx
 .loop:
     xor ax, ax      ; Clear ax
     int 0x16        ; Get a character
@@ -26,12 +27,14 @@ input:
     je .enter
 
     mov [di], al    ; Add the input to userInput
+    inc cl
     inc di
     jmp .loop
 .enter:
     mov al, 0x0a    ; Print LF
     int 0x10
-    mov byte [di], 0; NULL terminate userInput (Replaces CR)
+    mov byte [di], 0 ; NULL terminate userInput (Replaces CR)
+    mov byte [inputLen], cl
 
     mov al, [userInput]
     cmp al, 'H'
@@ -46,23 +49,101 @@ input:
 ; Load Program - Takes userInput and tries to run that file
 ;
 loadProgram:
-    mov ax, userInput
-    ; Get filetable into [es:di]
+    mov di, userInput
     mov bx, FILETAB_LOC
     mov es, bx
-    xor bx, bx
-    mov di, bx
+    xor bx, bx      ; Get [es:bx] to be start of filetable
+.nextCh:
+    mov al, [es:bx]
+    cmp al, '}'     ; Check for end of filetable
+    je .notFound
 
-    repne scasb     ; Scan for string at ax, in string at di
-    je .found
+    cmp al, [di]    ; Check for starting character
+    je .beginSearch
 
-    mov si, notFoundMsg
+    inc bx
+    jmp .nextCh
+.beginSearch:
+    push bx         ; Save position, if it doesn't equal
+    mov byte cl, [inputLen]
+.searchLoop:
+    mov al, [es:bx]
+    inc bx
+    cmp al, [di]
+    jne .restartSearch
+
+    dec cl
+    jz .match
+    inc di
+    jmp .searchLoop
+.match:
+    mov al, [es:bx]
+    cmp al, ':'     ; Check if we are at the end of a filename
+    je executeProgram
+.restartSearch:
+    mov di, userInput
+    pop bx
+    inc bx
+    jmp .nextCh
+.notFound:
+    mov si, fileNotFoundMsg
+    call print
+    jmp input
+    
+; Expects [es:bx] to point to a sector number folowed by a comma ('XX,' where X is 0-9)
+executeProgram:
+    mov cl, 10      ; Get 10 to multiply with
+    xor al, al      ; Reset al
+    inc bx          ; Skip ':'
+.getSectorNum:
+    mov dl, [es:bx]
+    inc bx
+    cmp dl, ','     ; Check if its end of sector number
+    je .load
+    cmp dl, '0'     ; Check if it is a digit 0-9
+    jl .notFound
+    cmp dl, '9'
+    jg .notFound
+    sub dl, '0'     ; Convert ASCII char to an integer
+    mul cl          ; ax *= cl (al *= 10)
+    add al, dl      ; al += dl
+    jmp .getSectorNum
+.notFound:
+    mov si, sectorNotFoundMsg
+    call print
+    jmp input
+.load:
+    mov cl, al      ; Sector
+
+    mov ah, 0       ; Reset disk system
+    mov dl, byte [driveNumber]
+    int 0x13
+
+    mov bx, PROGRAM_LOC
+    mov es, bx
+    xor bx, bx      ; [es:bx] - Place to load out program
+
+    mov ah, 2       ; Read sectors into memory
+    mov dl, byte [driveNumber]
+    mov al, 1       ; Read 1 sector
+    mov ch, 0       ; Cylinder
+    mov dh, 0       ; Head
+    int 0x13
+    jnc .loaded     ; Loaded file successfully
+
+    mov si, programLoadFailMsg
     call print
 
     jmp input
-.found:
+.loaded:
+    mov ax, PROGRAM_LOC
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+    mov ss, ax
 
-    jmp input
+    jmp PROGRAM_LOC:0x0000
 
 ;
 ; Help - Prints the help message (helpMsg)
@@ -163,10 +244,13 @@ reboot: jmp 0xffff:0x0000
 ; --------
 ;   Data
 ; --------
+driveNumber: db 0
+
 startMsg: db "kern.", ENDL, ENDL, 0 ; The bootup message
 prompt: db "> ", 0 ; Prompt for input
-newline: db ENDL, 0 ; CRLF
-notFoundMsg: db "File not found!", ENDL, 0
+fileNotFoundMsg: db "File not found!", ENDL, 0 ; User tries to load nonexistent file
+sectorNotFoundMsg: db "Sector not found!", ENDL, 0 ; File in an incorrect sector in filetable
+programLoadFailMsg: db "Failed while loading program!", ENDL, 0 ; File load fail
 
 browserMsg: db " Filename         Sector ", ENDL, \
                "----------       --------", ENDL, 0
@@ -177,9 +261,10 @@ helpMsg: db "Available Commands:", ENDL, \
             "H - Help", ENDL, \
             "R - Reboot", ENDL, 0
 
-userInput: db 0
 inputLen: db 0
+userInput: db 0
 
 FILETAB_LOC equ 0x1000
+PROGRAM_LOC equ 0x8000
 
 times 2*512-($-$$) db 0
diff --git a/src/print.asm b/src/print.asm
index b399030..816c123 100644
--- a/src/print.asm
+++ b/src/print.asm
@@ -47,3 +47,7 @@ printHex:
     ret
 
 hexString: db "0x0000", 0
+
+; Usefull definitions
+%define ENDL 0x0a, 0x0d
+newline: db ENDL, 0 ; CRLF