After initializing a dynamic char array, all signs are equal to zeros [closed]

Question

I'm trying to write the kernel in C, without stdlib and other libraries, all dynamic char arrays written in advance and without using calloc or malloc, here is an example code:

char* d="hello world!!!";
print_char(d[0],-1,-1,RED_ON_WHITE);

int print_char(char c, int col, int row, char attr) {
    unsigned char *vidmem = (unsigned char*) VIDEO_ADDRESS;
    int offset;
    if (col >= 0 && row >= 0) offset = get_offset(col, row);
    else offset = get_cursor_offset();

    vidmem[offset] = c;
    vidmem[offset+1] = attr;
    offset += 2;

    set_cursor_offset(offset);
    return offset;
}

int get_cursor_offset() {
    port_byte_out(REG_SCREEN_CTRL, 14);
    int offset = port_byte_in(REG_SCREEN_DATA) << 8; /* High byte: << 8 */
    port_byte_out(REG_SCREEN_CTRL, 15);
    offset += port_byte_in(REG_SCREEN_DATA);
    return offset * 2; /* Position * size of character cell */
}

void set_cursor_offset(int offset) {
    /* Similar to get_cursor_offset, but instead of reading we write data */
    offset /= 2;
    port_byte_out(REG_SCREEN_CTRL, 14);
    port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset >> 8));
    port_byte_out(REG_SCREEN_CTRL, 15);
    port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset & 0xff));
}

int get_offset(int col, int row) { return 2 * (row * MAX_COLS + col); }
int get_offset_row(int offset) { return offset / (2 * MAX_COLS); }

It does not print anything, but what is generated in a non-dynamic array prints.

Compile on Windows:

gcc -g -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs -c kernel/kernel.c -o kernel/kernel.o -std=c99
gcc -g -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs -c kernel/util.c -o kernel/util.o -std=c99
gcc -g -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs -c drivers/ports.c -o drivers/ports.o -std=c99
gcc -g -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs -c drivers/screen.c -o drivers/screen.o -std=c99
nasm -fbin boot/bootsect.asm -o boot/bootsect.bin
nasm -felf boot/kernel-entry.asm -o boot/kernel-entry.o
ld -mi386pe -o kernel.elf -Ttext 0x1000 boot/kernel-entry.o kernel/kernel.o kernel/util.o drivers/ports.o drivers/screen.o
objcopy -O binary kernel.elf kernel.bin
type boot\\bootsect.bin kernel.bin > os-image.bin
qemu-system-i386 -fda os-image.bin

Answer 1

You have specified -nostartfiles making you responsible for the C runtime environment start-up and initialisation. Part of that initialisation is to implement the static initialisers. Without that:

char* d = "hello world!!!" ;

will do nothing. It is not clear which if any of the object modules you have linked if any contain the start-up code. By convention there would be a crt0.o for that.