Ukulinganisa iLinus Torvalds: Yenza eyakho inkqubo yokusebenza ukusuka ekuqaleni (I)

Okokuqala, phawula ukuba eli nqaku lam lokuqala kwaye ndiyathemba ukuba nonke niyayithanda.

Kolu luhlu siza kuxelisa Linus Torvalds, Siza kwenza inkqubo yethu yokusebenza ukusuka ku-0. Kulesi siqendu sokuqala siza kubona i-boot kwaye siza kufaka isicatshulwa kwiscreen kwi-kernel yethu.

Kwimeko yam inkqubo yokusebenza ibizwa ngokuba OkulandelayoDivel. Isigqibo sokuqala esimele sisenze ngokukhawuleza xa siqwalasela inkqubo yokusebenza yintoni i-bootloader eya kuba yiyo?

Nazi iindlela ezahlukeneyo, kwaye sinokudala enye ngokwethu; nangona kunjalo kule khokelo ndiza kuyisebenzisa GRUB, kuba uninzi lwazi ngakumbi okanye luyinto encinci ngaye. Sakha ifolda eya kuba yingcambu yenkqubo yethu yokusebenza kwaye apho senza i / boot / grub ifolda

mkdir nextroot && cd nextroot

mkdir -p boot/grub

Apho senza ifayile yegrub.cfg ngolu hlobo lulandelayo:

menuentry "NextDivel" {
echo "Booting NextDivel"
multiboot /next/START.ELF
boot
}


Kule fayile sibonile ukuba njani GRUB siyakulayisha i-kernel yethu, kule meko, kwi /next/START.ELF. Ngoku kufuneka senze i-kernel yethu.

Ngale nto siza kuyidinga GCC y GAS (isihlanganisi seprojekthi GNU, ihlala iza ne-gcc). Ke siza kwenza i-kernel.

Kuqala senza ifayile ebizwa ngokuba yi-kernel.asm. Le fayile iya kuba nenqaku lokuqala le-kernel yethu kwaye iya kuchaza kwakhona i-multiboot (inqaku lezinye i-bootloaders ezinje GRUB). Umxholo we kernel.asm uya kuba:

.text
.globl start
start:
jmp multiboot_entry
.align 4
multiboot_header:
.long 0x1BADB002
.long 0x00000003
.long -(0x1BADB002+0x00000003)
multiboot_entry:
movl $(stack + 0x4000), %esp
call NextKernel_Main
loop: hlt
jmp loop
.section ".bss"
.comm stack,0x4000

Yonke into enxulumene ne-multiboot kukulandela nje imigaqo ayikho enye into. Yonke into iza kuqala ekuqaleni, iya kubiza i-multiboot_entry, siya kuchaza i-multiboot header kwi-4k yokuqala kwaye siza kuyibeka (nge-movl).

Emva kwexesha sibiza i-NextKernel_Main eyi-kernel C yethu yokusebenza. Emngxunyeni siyema ukumisa ikhompyuter. Oku kudityaniswa kunye:

as -o kernel.o -c kernel.asm

Ngoku sizakungena kwinkqubo ku-C. Uyakucinga ukuba ngoku yonke into sisiqwenga sekhekhe, sibeka u ukuprinta en eyona yiyo lonto, siyenzile.

Ewe hayi, kuba ukuprinta y eyona Le yimisebenzi echazwe yinkqubo yokusebenza, kodwa siyayenza! Singasebenzisa kuphela imisebenzi esizichaza ngayo.

Kwizahluko ezizayo ndiza kuthetha ngendlela yokubeka ilayibrari yethu C (glibc, bionic, newlibc) kodwa amaxesha ngamaxesha. Sithethile ukuba sifuna ukubeka isicatshulwa kwiscreen, kulungile ke siza kubona ukuba senza njani.

Zimbini iindlela onokukhetha kuzo, enye kukutsalela umnxeba BIOS kwaye enye kukulawula imemori yesikrini ngokuthe ngqo. Siza kuyenza le yokugqibela kuba icacile kwi-C kwaye iya kusivumela ukuba siyenze xa singena kwimowudi ekhuselweyo.

Senza ifayile ebizwa ngokuba yiNextKernel_Main.c ngalo mxholo ulandelayo:

int NextKernel_Main()
{
char *str = "NextDivel says Hello World", *ch;
unsigned short *vidmem = (unsigned short*) 0xb8000;
unsigned i;
for (ch = str, i = 0; *ch; ch++, i++)
vidmem[i] = (unsigned char) *ch | 0x0700;
return 0;
}

Ngale nto sisebenzisa ngokuthe ngqo inkumbulo VGA kunye nomlinganiswa ngohlobo esilubhalayo. Sihlanganisa ngokukhubaza i-stdlib:
gcc -o NextKernel_Main.o -c NextKernel_Main.c -nostdlib -fPIC -ffreestanding

Ukuba ukwenzile oku, uya kufuna ukuzama inkqubo yakho entsha yokusebenza ngoku, kodwa asikenzi okwangoku. Sifuna ifayile encinci exelela umhlanganisi ukuba yeyiphi kwifayile yokushiya icandelo ngalinye. Oku kwenziwa ngeskripthi sokudibanisa. Sakha ikhonkco.ld:

ENTRY(start)
SECTIONS
{
. = 0x00100000;
.multiboot_header :
{
*(.multiboot_header)
}
.text :
{
code = .; _code = .; __code = .;
*(.text)
. = ALIGN(4096);
}
.data :
{
data = .; _data = .; __data = .;
*(.data)
*(.rodata)
. = ALIGN(4096);
}
.bss :
{
bss = .; _bss = .; __bss = .;
*(.bss)
. = ALIGN(4096);
}
end = .; _end = .; __end = .;
}


Ngale nto sichaza indawo yecandelo ngalinye kunye nendawo yokungena, qala, esiyichaze kwi kernel.asm. Ngoku singamanyanisa yonke le ngqungquthela:

gcc -o START.ELF kernel.o NextKernel_Main.o -Tlink.ld -nostdlib -fPIC -ffreestanding -lgcc

Ngoku sikopa START.ELF ukuya / ngokulandelayo ngaphakathi kwifolda yethu efanisa ingcambu yenkqubo yethu yokusebenza. Siya kwifolda yengcambu yenkqubo yethu entsha yokusebenza kunye nekhonsoli kwaye siqinisekise ukuba kukho iifayile ezimbini: enye / boot / grub / grub.cfg kunye nenye / elandelayo / START.ELF.

Siya kwisikhombisi esingasentla kwaye sibize isixhobo sokwenza i-ISO ngeGRUB ebizwa grub-mkrescue

grub-mkrescue -o nextdivel.iso nextroot

Nje ukuba sikwenze oku siya kuba ne- ISO. Le ISO inokuvulwa kwiikhompyuter x86 (Iibhithi ezingama-64) kunye noomatshini ababonakalayo. Ukuyivavanya, ndiza kuyisebenzisa IQEMU. Siyabiza IQEMU kumgca wokuyalela:

qemu-system-i386 nextdivel.iso

Uya kuqala Ulwandle kwaye kamva siya kuba nazo GRUB. Emva kwexesha ukuba yonke into ichanekile siza kubona ibinzana lethu.
Uya kucinga ukuba kunzima, ndiyaphendula, ewe kunjalo.

Ngokwenene ukwenza inkqubo yokusebenza kunzima kwaye le apha ayenzi nto iluncedo. Kwizahluko ezizayo siza kubona indlela yokuphatha imibala kwiscreen, ukugcina imemori kwaye ukuba ndinako, indlela yokufumana idatha kwikhibhodi.

Ukuba umntu akafuni ukukopa yonke into apha, ndinendawo yokugcina izinto GitHub (ngakumbi ngakumbi) ngenkqubo yokusebenza OkulandelayoDivel. Ukuba ufuna ukudibanisa OkulandelayoDivel kufuneka une-git kunye ne-cmake:

git clone https://github.com/AdrianArroyoCalle/next-divel
cd next-divel
mkdir build && cd build
cmake ..
make
make DESTDIR=next install
chmod +x iso.sh
./iso.sh
qemu-system-i386 nextdivel.iso


Ndiyakukhuthaza ukuba usebenzisane kwi-NextDivel ukuba unexesha kwaye unqwenela ukwenza inkqubo yokusebenza. Mhlawumbi ungaphezulu kweLinux ... ixesha liza kuxela.