Te Whakahoahoa i nga Toroa Linus: Hangaia to punaha whakahaere mai i te maaka (I)

Ko te tuatahi, ko te korero ko taku tuhinga tuatahi tenei me te tumanako ka pai katoa ki a koutou.

I tenei rarangi ka tirohia e tatou Rinuha Torvalds, ka hangaia e maatau taatau punaha whakahaere mai i te 0. I tenei waahanga tuatahi ka kite matou i te puutu ka hoatu he panui ki runga i te mata mai i a maatau kernel.

Ki ahau nei ka kiia te punaha whakahaere PanukuTira. Ko te whakataunga tuatahi me whakatau wawe ka whakaarohia e maatau te punaha whakahaere he aha te take o te bootloader?

Anei he maha nga rereketanga, a ka taea ano e taatau te hanga tetahi; heoi i tenei akoranga ka whakamahia e ahau GRUB, na te mea ko te nuinga e mohio ana he iti ake ranei tetahi mea e pa ana ki a ia. Ka hangaia e maatau he kopaki ka waiho hei pakiaka mo ta maatau punaha whakahaere, a, i reira ka hangaia te kopae / whakaara / grub

mkdir nextroot && cd nextroot

mkdir -p boot/grub

I reira ka hangaia e matou te konae grub.cfg penei:

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


I roto i tenei konae kua kite matou pehea GRUB ka utaina a tatou pata, i tenei keehi, i te / panui /START.ELF. Na me hanga e tatou taatau pata.

Mo tenei ka hiahiatia e maatau te GCC y GAS (te kaiwhakaemi o te kaupapa GNU, ka tae mai me te gcc). No reira ka hangaia e tatou te pata.

Tuatahi ka hanga e matou he konae e kiia nei ko te kernel.asm. Kei roto i tenei konae te timatanga o a tatou pata, me te tautuhi hoki i te multiboot (he ahuatanga na etahi bootloaders penei GRUB). Ko nga korero o te kernel.asm ka:

.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

Ko nga mea katoa e pa ana ki te multiboot he whai noa i te whakatakotoranga kaore he mea ke. Ka tiimata nga mea katoa i te tiimatanga, ka karangahia te multiboot_entry, kua tautuhia e matou te pane multiboot i te 4k tuatahi ka waiho e matou (me te movl).

I muri mai ka karangahia a NextKernel_Main ko ta maatau kernel C mahi. I te koropiko ka tu maatau ki te aukati i te rorohiko. Ka whakahiato tenei ki:

as -o kernel.o -c kernel.asm

Inaianei ka uru taatau ki te hotaka whakaari i roto i te C. Ka whakaaro koe inaianei he keke keke nga mea katoa, ka makaia e maatau Tuhinga en matua ana koira, kua oti i a matou.

Ana kaore, mai i tenei wa Tuhinga y matua he mahinga era e tautuhia ana e te punaha whakahaere, engari kei te hangaia e maatau! Ka taea noa e taatau te whakamahi i nga mahi e tautuhia ana e taatau.

I nga upoko o muri ka korero ahau me pehea te tuu i ta tatou ake whare pukapuka C (glibc, bionic, newlibc) engari he wa ano ia wa. Kua korero maatau e hiahia ana matou ki te tuku tuhinga ki runga i te mata, kaati ka kite taatau pehea.

E rua nga waahanga, ko tetahi ki te karanga i te BIOS me tetahi atu ko te whakahaere tika i te maaramatanga mata. Ka mahi maatau i nga mea o muri na te mea he maamaa ake i te C ana ka tukuna ano ma tatou ka uru atu ki te momo ahuru.

Ka hangaia e matou he konae e huaina ana ko NextKernel_Main.c me nga korero e whai ake nei:

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;
}

Ma tenei ka tika te whakamahi i o maatau VGA me nga ahuatanga ma te taangata e tuhi ana matou. Ka whakahiatohia e matou ma te whakakore i te stdlib:
gcc -o NextKernel_Main.o -c NextKernel_Main.c -nostdlib -fPIC -ffreestanding

Mena kua tae noa mai koe ki tenei wa, ka hiahia koe ki te whakamatautau i to punaha whakahaere hou-inaianei, engari kaore ano kia oti. Kei te hiahia maatau tetahi konae iti e kii ana ki te kaitautoko kei hea te konae waiho ai ia waahanga. Ka mahia tenei ma te tuhinga hono. Hangaia e matou te hono.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 = .;
}


Ma tenei ka tautuhia te waahi mo ia waahanga me te waahi tomokanga, tiimata, kua tautuhia e maatau ki te kernel.asm. I tenei ka taea e taatau te whakakotahi i tenei kaupapa katoa:

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

Na ka kape taatau i te timatanga. KATOA ki / muri i roto i ta maatau kopaki e whakatauira ana i te pakiaka o ta maatau punaha whakahaere Ka haere matou ki te kopae pakiaka o ta maatau punaha whakahaere hou me te papatohu me te tohu kei te rua nga konae: kotahi /boot/grub/grub.cfg me tetahi /e taera /START.ELF.

Ka haere matou ki te raarangi o runga ka karanga ki tetahi taputapu hanga ISO me GRUB i kiia grub-mkrescue

grub-mkrescue -o nextdivel.iso nextroot

Ka oti ana tenei ka whai maatau ISO. Ka taea te whakatuwhera i tenei ISO i runga i nga rorohiko x86 (64 nga paraire ano) me nga miihini mariko. Hei whakamatautau, ka whakamahia e au Tuhinga. Ka karanga matou Tuhinga mai i te raina whakahau:

qemu-system-i386 nextdivel.iso

Ka tiimata MoanaBIOS a muri ake ka riro i a maatau GRUB. A muri ake mena ka tika nga mea katoa ka kite taatau rerenga korero.
Ka whakaaro koe he uaua tenei, ka whakautu ahau, ae ra.

He uaua te hanga punaha whakahaere na te mea kaore e whai hua tetahi i konei. I nga upoko o muri ake nei ka kite taatau me pehea te whakahaere tae i runga i te mata, kia rahuitia te mahara me mena ka taea e au, me pehea te tango raraunga mai i te papapihi.

Mena kaore tetahi e hiahia ki te kape i nga mea katoa o konei, he whare putunga taku kei GitHub (he taipitopito atu) me te punaha whakahaere PanukuTira. Mena kei te hiahia koe ki te whakahiato PanukuTira me whai git me cmake koe:

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


Ka akiaki ahau ki a koe kia mahi tahi i runga i a NextDivel mena he waa taau me to hiahia ki te hanga punaha whakahaere. Akene he pai ake i te Linux ... ka kii te wa.