Meaty Skeleton: Difference between revisions

{{FirstPerson}}

{{BeginnersWarning}}

 

operating system in the [[Stan Dard]] style suitable for further modification or

as inspiration for your initial operating system version. The [[Bare Bones]]

 

== Building a Cross-Compiler ==

 

You ''must'' use a [[GCC Cross-Compiler]] in this tutorial as in the

mandatory options the project makefile requires:

 

# Default CFLAGS:

CFLAGS?=-O2 -g

# Add mandatory options to CFLAGS:

CFLAGS:=$(CFLAGS) -Wall -Wextra

 

== Architecture Directories ==

You can easily download the source code using [[Git]] from the [https://gitlab.com/sortie/meaty-skeleton Meaty Skeleton Git repository]. This is preferable to doing a manual error-prone copy, as you may make a mistake or whitespace may get garbled due to bugs in our syntax highlighting. To clone the git repository, do:

 

git clone https://gitlab.com/sortie/meaty-skeleton.git

 

Check for differences between the git revision used in this article and what you cloned (empty output means there is no difference):

git diff 084d1624bedaa9f9e395f055c6bd99299bd97f58..master

 

Operating systems development is about being an expert. Take the time to read the code carefully through and understand it. Please seek further information and help if you don't understand aspects of it. This code is minimal and almost everything is done deliberately, often to pre-emptively solve future problems.

==== kernel/include/kernel/tty.h ====

 

#ifndef _KERNEL_TTY_H

#define _KERNEL_TTY_H

 

#endif

 

==== kernel/Makefile ====

 

DEFAULT_HOST!=../default-host.sh

HOST?=DEFAULT_HOST

 

-include $(OBJS:.o=.d)

 

==== kernel/kernel/kernel.c ====

 

#include <stdio.h>

 

printf("Hello, kernel World!\n");

}

 

==== kernel/arch/i386/tty.c ====

 

#include <stdbool.h>

#include <stddef.h>

terminal_write(data, strlen(data));

}

 

==== kernel/arch/i386/crtn.S ====

==== kernel/arch/i386/vga.h ====

 

#ifndef ARCH_I386_VGA_H

#define ARCH_I386_VGA_H

 

#endif

 

==== kernel/arch/i386/make.config ====

 

KERNEL_ARCH_CFLAGS=

KERNEL_ARCH_CPPFLAGS=

$(ARCHDIR)/boot.o \

$(ARCHDIR)/tty.o \

 

==== kernel/arch/i386/crti.S ====

==== libc/include/string.h ====

 

#ifndef _STRING_H

#define _STRING_H 1

 

#endif

 

==== libc/include/stdio.h ====

 

#ifndef _STDIO_H

#define _STDIO_H 1

 

#endif

 

==== libc/include/sys/cdefs.h ====

 

#ifndef _SYS_CDEFS_H

#define _SYS_CDEFS_H 1

 

#endif

 

==== libc/include/stdlib.h ====

 

#ifndef _STDLIB_H

#define _STDLIB_H 1

 

#endif

 

==== libc/Makefile ====

 

DEFAULT_HOST!=../default-host.sh

HOST?=DEFAULT_HOST

-include $(OBJS:.o=.d)

-include $(LIBK_OBJS:.o=.d)

 

==== libc/stdlib/abort.c ====

 

#include <stdio.h>

#include <stdlib.h>

__builtin_unreachable();

}

 

==== libc/string/memmove.c ====

 

#include <string.h>

 

return dstptr;

}

 

==== libc/string/strlen.c ====

 

#include <string.h>

 

return len;

}

 

==== libc/string/memcmp.c ====

 

#include <string.h>

 

return 0;

}

 

==== libc/string/memset.c ====

 

#include <string.h>

 

return bufptr;

}

 

==== libc/string/memcpy.c ====

 

#include <string.h>

 

return dstptr;

}

 

==== libc/stdio/puts.c ====

 

#include <stdio.h>

 

return printf("%s\n", string);

}

 

==== libc/stdio/putchar.c ====

 

#include <stdio.h>

 

return ic;

}

 

==== libc/stdio/printf.c ====

 

#include <limits.h>

#include <stdbool.h>

return written;

}

 

==== libc/arch/i386/make.config ====

 

ARCH_CFLAGS=

ARCH_CPPFLAGS=

 

ARCH_HOSTEDOBJS=\

 

==== libc/.gitignore ====

==== build.sh ====

 

#!/bin/sh

set -e

(cd $PROJECT && DESTDIR="$SYSROOT" $MAKE install)

done

 

You should make this executable script executable by running:

chmod +x build.sh

 

==== clean.sh ====

 

#!/bin/sh

set -e

rm -rf isodir

rm -rf myos.iso

 

You should make this executable script executable by running:

chmod +x clean.sh

 

==== config.sh ====

 

SYSTEM_HEADER_PROJECTS="libc kernel"

PROJECTS="libc kernel"

export CC="$CC -isystem=$INCLUDEDIR"

fi

 

==== default-host.sh ====

 

#!/bin/sh

echo i686-elf

 

You should make this executable script executable by running:

chmod +x default-host.sh

 

==== headers.sh ====

 

#!/bin/sh

set -e

(cd $PROJECT && DESTDIR="$SYSROOT" $MAKE install-headers)

done

 

You should make this executable script executable by running:

chmod +x headers.sh

 

==== iso.sh ====

 

#!/bin/sh

set -e

EOF

grub-mkrescue -o myos.iso isodir

 

You should make this executable script executable by running:

chmod +x iso.sh

 

==== qemu.sh ====

 

#!/bin/sh

set -e

 

qemu-system-$(./target-triplet-to-arch.sh $HOST) -cdrom myos.iso

 

You should make this executable script executable by running:

chmod +x qemu.sh

 

==== target-triplet-to-arch.sh ====

 

#!/bin/sh

if echo "$1" | grep -Eq 'i[[:digit:]]86-'; then

echo "$1" | grep -Eo '^[[:alnum:]_]*'

fi

 

You should make this executable script executable by running:

chmod +x target-triplet-to-arch.sh

 

==== .gitignore ====

the source tree by invoking:

 

./clean.sh

 

You can install all the system headers into the system root without relying on

[[Hosted GCC Cross-Compiler]], by invoking:

 

./headers.sh

 

You can build a bootable cdrom image of the operating system by invoking:

 

./iso.sh

 

It's probably a good idea to create a quick ''build-and-then-launch'' short-cut

like used in this example to run the system in your favorite emulator quickly:

 

./qemu.sh

 

== Troubleshooting ==

* [[topic:36584|A link error found & fixed]]

 

[[Category:C]]