Add console text coloring support (ANSI escape codes)

[BrightCat14]

Add console text coloring support (ANSI escape codes)

Currently, the console output is monochrome. It would be great to add support for colored text output using ANSI escape codes.

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What needs to be done:

• Implement parsing of basic ANSI escape sequences for colors (e.g., \x1b[31m for red).
• Update console output code to handle color changes.
• Support at least these colors: red, green, yellow, blue, magenta, cyan, white, and reset.
• Ensure that color resets properly to default after colored text.
• Write simple test programs demonstrating colored text output.

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Why this task?

• Adds visual appeal and usability to the console.
• Helps users highlight important messages.
• A relatively simple and fun feature to implement — great for beginners and intermediate contributors.

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Who can do this?

• Suitable for beginners interested in low-level text output handling.
• A good way to get familiar with console I/O and escape sequences.

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If you have any questions or need guidance, feel free to ask!

[f4ni]

Hi, I'm interested in working on this

[BrightCat14]

Hi, I'm interested in working on this

Hi @fani1016,

That’s great to hear! Feel free to work on this issue. If you need any guidance or have questions about the implementation (e.g., where to start, how to test), just let me know.

A few tips:

• The console output logic is in src/kernel.c.
• You can test ANSI codes using simple k_printf calls initially.

I’ll assign the issue to you—happy coding! 🎨

[BrightCat14]

Hey @fani1016, any updates on the console color support?

[f4ni]

Hello, thanks for assigning me this issue, I just saw your notification. I'll start working on it

[f4ni]

Hello @BrightCat14 , after adding the support the colors are not as expected in the qemu emulator because it does not support ansi-color-codes as you cans see below:

[BrightCat14]

Hello @BrightCat14 , after adding the support the colors are not as expected in the qemu emulator because it does not support ansi-color-codes as you cans see below:

Hi @fani1016, I think you might have misunderstood my task. Let me try to explain the exact plan in more detail:

Current Architecture

1. All rendering is in kernel.c using VGA text mode (0xB8000)
2. Current color: only WHITE_ON_BLACK (0x0F) in colors.h
3. Output goes through k_putc() and k_printf()

Task Requirements

We need to:

1. Add color constants to colors.h:

// colors.h
#define VGA_BLACK     0x00
#define VGA_RED       0x04
#define VGA_GREEN     0x02
#define VGA_YELLOW    0x0E
// ... other colors ...
#define VGA_WHITE     0x0F

2. Modify k_printf() to:

• Detect ANSI sequences (\x1b[31m)
• Parse color codes
• Convert to VGA attributes
• Pass correct color to k_putc()

Implementation Example

// In k_printf():
while (*fmt) {
    if (*fmt == '\x1b' && fmt[1] == '[') {
        fmt += 2; // Skip ESC[
        uint8_t color = WHITE_ON_BLACK;
        
        // Parse color code (simplified)
        if (*fmt == '3') { // Foreground
            fmt++;
            switch (*fmt++) {
                case '1': color = (color & 0xF0) | VGA_RED; break;
                case '2': color = (color & 0xF0) | VGA_GREEN; break;
                // ... other colors ...
            }
        }
        while (*fmt != 'm') fmt++; // Skip to 'm'
        fmt++; // Skip 'm'
        continue;
    }
    k_putc(*fmt++, color);
}

Key Points

1. We're NOT using terminal ANSI - we parse them and convert to VGA
2. QEMU behavior doesn't matter - we control the VGA buffer directly
3. Start with basic colors (red/green/blue), then expand