Hello! First, I just want to say this is really neat. I was looking and I didn't find a kernel panic file or function. I wanted to suggest adding one (I would do it but I'm not sure exactly how to do it).

An error causing the termination of the building of the toolchain. More specifically, this was using @unsafecast's fork, of build-test branch, PR #37

To reproduce:

$ ./scripts/build-tools.sh

[ OKAY ] Framebuffer initialized [ OKAY ] ACPI initialized [ INFO ] Brought up CPU #0 [ OKAY ] SMP initialized

CPU 0: Page Fault at ffffffff80208fa6

I have all of the required tools mentioned in the README file, have built the toolchain (I'm on a 64 bit system so I used make toolchain), and have run it through Make.

What could be causing this? Thanks!

Running ./scripts/build-tools.sh results in the following error:

2021-05-12 15:39:11 URL: ftp://gcc.gnu.org/pub/gcc/infrastructure/mpfr-3.1.4.tar.bz2 [1279284] -> "./mpfr-3.1.4.tar.bz2" [1]
error: Cannot download mpc-1.0.3.tar.gz from ftp://gcc.gnu.org/pub/gcc/infrastructure/

Previous command failed with exit code 1; quitting...

A lot of repositories use main instead of master as the name of the primary branch. The reasoning behind a lot of this is political and uselessly controversial but it may be worth considering following what is current practice and saving a couple characters when typing.

I haven't implemented this function on the exception handler because:

1. The exception handler is too unstable, even turning off optimizations can crash the OS
2. My function is unstable, it crashed KVM several times

It's pretty self-explanatory, (I think) this could be fixed by changing declarations on headers to "extern".

LD output:

ld: src/kernel/text.o:(.bss+0x0): multiple definition of `char_font'; src/misc/printf.o:(.bss+0x0): first defined here
ld: src/kernel/text.o:(.bss+0x400): multiple definition of `framebuffer'; src/misc/printf.o:(.bss+0x400): first defined here
ld: src/kernel/text.o:(.bss+0x408): multiple definition of `framebuffer_width'; src/misc/printf.o:(.bss+0x408): first defined here
ld: src/kernel/text.o:(.bss+0x40c): multiple definition of `framebuffer_height'; src/misc/printf.o:(.bss+0x40c): first defined here
ld: src/kernel/text.o:(.bss+0x410): multiple definition of `framebuffer_bpp'; src/misc/printf.o:(.bss+0x410): first defined here
ld: src/kernel/text.o:(.bss+0x414): multiple definition of `RED'; src/misc/printf.o:(.bss+0x414): first defined here
ld: src/kernel/text.o:(.bss+0x418): multiple definition of `DARK_RED'; src/misc/printf.o:(.bss+0x418): first defined here
ld: src/kernel/text.o:(.bss+0x41c): multiple definition of `GREEN'; src/misc/printf.o:(.bss+0x41c): first defined here
ld: src/kernel/text.o:(.bss+0x420): multiple definition of `DARK_GREEN'; src/misc/printf.o:(.bss+0x420): first defined here
ld: src/kernel/text.o:(.bss+0x424): multiple definition of `YELLOW'; src/misc/printf.o:(.bss+0x424): first defined here
ld: src/kernel/text.o:(.bss+0x428): multiple definition of `DARK_YELLOW'; src/misc/printf.o:(.bss+0x428): first defined here
ld: src/kernel/text.o:(.bss+0x42c): multiple definition of `BLUE'; src/misc/printf.o:(.bss+0x42c): first defined here
ld: src/kernel/text.o:(.bss+0x430): multiple definition of `DARK_BLUE'; src/misc/printf.o:(.bss+0x430): first defined here
ld: src/kernel/text.o:(.bss+0x434): multiple definition of `MAGENTA'; src/misc/printf.o:(.bss+0x434): first defined here
ld: src/kernel/text.o:(.bss+0x438): multiple definition of `DARK_MAGENTA'; src/misc/printf.o:(.bss+0x438): first defined here
ld: src/kernel/text.o:(.bss+0x43c): multiple definition of `CYAN'; src/misc/printf.o:(.bss+0x43c): first defined here
ld: src/kernel/text.o:(.bss+0x440): multiple definition of `DARK_CYAN'; src/misc/printf.o:(.bss+0x440): first defined here
ld: src/kernel/text.o:(.bss+0x444): multiple definition of `WHITE'; src/misc/printf.o:(.bss+0x444): first defined here
ld: src/kernel/text.o:(.bss+0x448): multiple definition of `BLACK'; src/misc/printf.o:(.bss+0x448): first defined here
ld: src/kernel/text.o:(.bss+0x44c): multiple definition of `GRAY'; src/misc/printf.o:(.bss+0x44c): first defined here
ld: src/kernel/text.o:(.bss+0x450): multiple definition of `DARK_GRAY'; src/misc/printf.o:(.bss+0x450): first defined here
ld: src/kernel/text.o:(.bss+0x454): multiple definition of `BG'; src/misc/printf.o:(.bss+0x454): first defined here
ld: src/kernel/text.o:(.bss+0x458): multiple definition of `FG'; src/misc/printf.o:(.bss+0x458): first defined here
ld: src/kernel/text.o:(.bss+0x45c): multiple definition of `fg_color'; src/misc/printf.o:(.bss+0x45c): first defined here
ld: src/kernel/text.o:(.bss+0x460): multiple definition of `bg_color'; src/misc/printf.o:(.bss+0x460): first defined here
ld: src/kernel/text.o:(.bss+0x464): multiple definition of `x_pos_pixel'; src/misc/printf.o:(.bss+0x464): first defined here
ld: src/kernel/text.o:(.bss+0x468): multiple definition of `y_pos_pixel'; src/misc/printf.o:(.bss+0x468): first defined here
ld: src/kernel/text.o:(.bss+0x46c): multiple definition of `border'; src/misc/printf.o:(.bss+0x46c): first defined here
ld: src/kernel/kernel.o:(.bss+0x0): multiple definition of `char_font'; src/misc/printf.o:(.bss+0x0): first defined here
ld: src/kernel/kernel.o:(.bss+0x400): multiple definition of `framebuffer'; src/misc/printf.o:(.bss+0x400): first defined here
ld: src/kernel/kernel.o:(.bss+0x408): multiple definition of `framebuffer_width'; src/misc/printf.o:(.bss+0x408): first defined here
ld: src/kernel/kernel.o:(.bss+0x40c): multiple definition of `framebuffer_height'; src/misc/printf.o:(.bss+0x40c): first defined here
ld: src/kernel/kernel.o:(.bss+0x410): multiple definition of `framebuffer_bpp'; src/misc/printf.o:(.bss+0x410): first defined here
ld: src/kernel/kernel.o:(.bss+0x142c): multiple definition of `RED'; src/misc/printf.o:(.bss+0x414): first defined here
ld: src/kernel/kernel.o:(.bss+0x1430): multiple definition of `DARK_RED'; src/misc/printf.o:(.bss+0x418): first defined here
ld: src/kernel/kernel.o:(.bss+0x1434): multiple definition of `GREEN'; src/misc/printf.o:(.bss+0x41c): first defined here
ld: src/kernel/kernel.o:(.bss+0x1438): multiple definition of `DARK_GREEN'; src/misc/printf.o:(.bss+0x420): first defined here
ld: src/kernel/kernel.o:(.bss+0x143c): multiple definition of `YELLOW'; src/misc/printf.o:(.bss+0x424): first defined here
ld: src/kernel/kernel.o:(.bss+0x1440): multiple definition of `DARK_YELLOW'; src/misc/printf.o:(.bss+0x428): first defined here
ld: src/kernel/kernel.o:(.bss+0x1444): multiple definition of `BLUE'; src/misc/printf.o:(.bss+0x42c): first defined here
ld: src/kernel/kernel.o:(.bss+0x1448): multiple definition of `DARK_BLUE'; src/misc/printf.o:(.bss+0x430): first defined here
ld: src/kernel/kernel.o:(.bss+0x144c): multiple definition of `MAGENTA'; src/misc/printf.o:(.bss+0x434): first defined here
ld: src/kernel/kernel.o:(.bss+0x1450): multiple definition of `DARK_MAGENTA'; src/misc/printf.o:(.bss+0x438): first defined here
ld: src/kernel/kernel.o:(.bss+0x1454): multiple definition of `CYAN'; src/misc/printf.o:(.bss+0x43c): first defined here
ld: src/kernel/kernel.o:(.bss+0x1458): multiple definition of `DARK_CYAN'; src/misc/printf.o:(.bss+0x440): first defined here
ld: src/kernel/kernel.o:(.bss+0x145c): multiple definition of `WHITE'; src/misc/printf.o:(.bss+0x444): first defined here
ld: src/kernel/kernel.o:(.bss+0x1460): multiple definition of `BLACK'; src/misc/printf.o:(.bss+0x448): first defined here
ld: src/kernel/kernel.o:(.bss+0x1464): multiple definition of `GRAY'; src/misc/printf.o:(.bss+0x44c): first defined here
ld: src/kernel/kernel.o:(.bss+0x1468): multiple definition of `DARK_GRAY'; src/misc/printf.o:(.bss+0x450): first defined here
ld: src/kernel/kernel.o:(.bss+0x146c): multiple definition of `BG'; src/misc/printf.o:(.bss+0x454): first defined here
ld: src/kernel/kernel.o:(.bss+0x1470): multiple definition of `FG'; src/misc/printf.o:(.bss+0x458): first defined here
ld: src/kernel/kernel.o:(.bss+0x1474): multiple definition of `fg_color'; src/misc/printf.o:(.bss+0x45c): first defined here
ld: src/kernel/kernel.o:(.bss+0x1478): multiple definition of `bg_color'; src/misc/printf.o:(.bss+0x460): first defined here
ld: src/kernel/kernel.o:(.bss+0x147c): multiple definition of `x_pos_pixel'; src/misc/printf.o:(.bss+0x464): first defined here
ld: src/kernel/kernel.o:(.bss+0x1480): multiple definition of `y_pos_pixel'; src/misc/printf.o:(.bss+0x468): first defined here
ld: src/kernel/kernel.o:(.bss+0x1484): multiple definition of `border'; src/misc/printf.o:(.bss+0x46c): first defined here
ld: src/kernel/syscall.o:(.bss+0x0): multiple definition of `idt'; src/kernel/kernel.o:(.bss+0x420): first defined here
ld: src/kernel/syscall.o:(.bss+0x1000): multiple definition of `idtp'; src/kernel/kernel.o:(.bss+0x1420): first defined here
ld: src/kernel/irq.o:(.bss+0x0): multiple definition of `idt'; src/kernel/kernel.o:(.bss+0x420): first defined here
ld: src/kernel/irq.o:(.bss+0x1000): multiple definition of `idtp'; src/kernel/kernel.o:(.bss+0x1420): first defined here
ld: src/kernel/font.o:(.data+0x0): multiple definition of `char_font'; src/misc/printf.o:(.bss+0x0): first defined here
ld: src/kernel/isr.o:(.bss+0x0): multiple definition of `idt'; src/kernel/kernel.o:(.bss+0x420): first defined here
ld: src/kernel/isr.o:(.bss+0x1000): multiple definition of `idtp'; src/kernel/kernel.o:(.bss+0x1420): first defined here
ld: src/kernel/fb.o:(.bss+0x0): multiple definition of `framebuffer'; src/misc/printf.o:(.bss+0x400): first defined here
ld: src/kernel/fb.o:(.bss+0x8): multiple definition of `framebuffer_width'; src/misc/printf.o:(.bss+0x408): first defined here
ld: src/kernel/fb.o:(.bss+0xc): multiple definition of `framebuffer_height'; src/misc/printf.o:(.bss+0x40c): first defined here
ld: src/kernel/fb.o:(.bss+0x10): multiple definition of `framebuffer_bpp'; src/misc/printf.o:(.bss+0x410): first defined here
ld: src/arch/x86_64/idt.o:(.bss+0x0): multiple definition of `idt'; src/kernel/kernel.o:(.bss+0x420): first defined here
ld: src/arch/x86_64/idt.o:(.bss+0x1000): multiple definition of `idtp'; src/kernel/kernel.o:(.bss+0x1420): first defined here
make: *** [Makefile:65: mandelbrotos.elf] Error 1```

Hi (again 😁)

In device.h I saw this:

// TODO: Make this resizable
#define MAX_DEVICES 256

Couldn't you just change #define to uint64_t (uint64_t max_devices 256) or size_t (size_t max_devices 256) to make it resizable, or am I not understanding this right?

Well, I wanted to help with this project, so I'll start with this. I also don't know if you will actually want to change the code layout or not :).

Separates kernel code, library code and headers from each other, in order to make code a bit cleaner(in my opinion):

• Kernel code: src
• Library code: src/lib
• Headers: src/include

This implementation of strlen(3) scrubs iteratively through memory so I figure putting that in a for statement is clearer to both humans and the compiler.

No need to increment s when you already have the index you need to check in memory (or probably a register). And you have to have that index in memory because that's the return value.

As far as I know this is the idiomatic solution; I've used this when I haven't wanted to include string.h.

We had two issues in the past with people not realizing they need to clone recursively since submodules, so I though it would be a good idea to do that :^)

Commits contain what I've written so far of the math library in math.c, a full template for everything in math.h, limits.h, and graphing code for testing in math_test/*. Note that it is unstable and probably broken in a few places, so maybe it should be a new branch until complete.

I cloned the repository and tried to compile and run the operating system, using the instructions written in the README but got an error message while compiling:

../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:41:(.stab+0x14): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:41:(.stab+0x20): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:41:(.stab+0x2c): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:44:(.stab+0x38): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:45:(.stab+0x44): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:47:(.stab+0x50): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:47:(.stab+0x5c): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:47:(.stab+0x68): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:47:(.stab+0x74): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:51:(.stab+0x80): relocation truncated to fit: R_X86_64_32 against `.text'
../../build/kernel//./sys/interrupts.asm.o:sys/interrupts.asm:54:(.stab+0x8c): additional relocation overflows omitted from the output
make[1]: *** [Makefile:39: ../../build/kernel/mandelbrotos.elf] Error 1
make[1]: Leaving directory '/home/user/dev/MandelbrotOS/src/kernel'
make: *** [Makefile:8: kernel] Error 2

After looking around and git checkouting to older commits I found out that commit #e2d8eedcfb62aee5b12c84466b4f86b40193500e added the -g compilation flag. Removing the flag fixed the problem.

After playing around with the Makefile for a bit I saw that when ASFLAGS gets the -g flag there's a compilation error but when CFLAGS gets it, there isn't.

One solution can be to have two different optimization-flag-variables, one for the assembler and one for C compiler, and another solution can be to remove the -g flag completely.

Considering there are multiple commits following the problematic commit, the problem might be a problem on my side, and could be a local fix in the author's machine. If there is a local fix, it should probably be noted in the README or added as part of the compilation process.