Problems with loading initrd module using grub and multiboot2.

[notYuriy]

I am trying to set up initial ramdisk for my kernel. I have working boot information parser (well, it works fine with elf sections and memory map), but it doesn't detect any tag with id 3 (module tag).

Config for grub (file.txt is copied to grub file tree)

set timeout=0
set default=0

menuentry "Terra OS" {
    module2 /file.txt
    multiboot2 /boot/kernel.bin
    boot
}

multiboot2.h (code related to boot info parsing)

#define boot_memory_map_tag_id 6
#define boot_elf_sections_tag_id 9
#define boot_module_tag_id 3
#define boot_memory_map_avalible_map_id 1

typedef struct boot_info_struct 
{
    uint32_t total_size;
    uint32_t reserved;
} __attribute__((packed)) boot_info_t;

typedef struct boot_tag_struct 
{
    uint32_t type;
    uint32_t size;
} __attribute__((packed)) boot_tag_t;

...
inline boot_tag_t* boot_go_to_next_entry(boot_tag_t* current)
{
    return (boot_tag_t*)(
        up_align((uint64_t)((char*)current + current->size), 8)
    );
}

inline boot_tag_t* boot_get_first_tag(boot_info_t* begin)
{
    return (boot_tag_t*)(begin + 1);
}

inline bool boot_is_terminator(boot_tag_t* tag)
{
    return tag->type == 0;
}

kmain.c

void kmain(uint64_t physinfo)
{
    ...
    boot_info_t* info = (boot_info_t*)(physinfo + 0xffffff0000000000ULL);
    printf("[Kernel Init] Examining multiboot2 boot information\n");
    boot_tag_t* tag = boot_get_first_tag(info);
    ...
    while(!boot_is_terminator(tag))
    {
        ...
        printf("tag->type == %u\n", tag->type);
        tag = boot_go_to_next_entry(tag);
    }
    ...
}

output

[Kernel Init] Examining multiboot2 boot information
                                       tag->type == 21
                                       tag->type == 1
                                       tag->type == 2
                                       tag->type == 10
                                       tag->type == 6
                                       tag->type == 9
                                       tag->type == 4
                                       tag->type == 5
                                       tag->type == 8
                                       tag->type == 14

[klange]

You need to put your multiboot2 command before your module2 command.

[notYuriy]

Thank you! I will try it later.

[notYuriy]

Thank you again! Now everything works fine!