Why does a elf file have so many unsused/wasted space - gcc

Question

I've been looking at loading a elf file into the memory, but in the process, I've found out that there is huge chunk of unused space in the file.
This is the elf file i got https://cyao.page/kernel.elf (~2.1Mib) and this is my linker script:
ENTRY(start)
OUTPUT_FORMAT(elf64-x86-64)
SECTIONS {
. = 0xC00000;
phys = .;
.text ALIGN(0x1000): {
code = .;
*(.text)
. = ALIGN(0x1000);
}
.rodata ALIGN(0x1000): {
*(.rodata*)
. = ALIGN(0x1000);
}
.data ALIGN(0x1000): {
data = .;
*(.data)
. = ALIGN(0x1000);
}
.bss ALIGN(0x1000): {
bss = .;
*(.bss)
. = ALIGN(0x1000);
}
end = .; _end = .; __end = .;
/DISCARD/ : {
*(.comment)
*(.note.gnu.build-id)
}
}
When I you look at the p_offset in the program header (in adress 0x40), you will see that the offset is 0x200000, and in all the section tables, all their's offset are bigger then 0x200000
The same goes with x86_64-elf-objdump
cdcontents/!kernel.bin: file format elf64-x86-64
cdcontents/!kernel.bin
architecture: i386:x86-64, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x000000000c000000
Program Header:
LOAD off 0x0000000000200000 vaddr 0x000000000c000000 paddr 0x000000000c000000 align 2**12
filesz 0x0000000000009384 memsz 0x000000000000b000 flags rwx
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 00006000 000000000c000000 000000000c000000 00200000 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .text.startup 00000094 000000000c006000 000000000c006000 00206000 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
2 .data 00001000 000000000c007000 000000000c007000 00207000 2**5
CONTENTS, ALLOC, LOAD, DATA
3 .rodata 00001000 000000000c008000 000000000c008000 00208000 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 .eh_frame 00000384 000000000c009000 000000000c009000 00209000 2**3
CONTENTS, ALLOC, LOAD, READONLY, DATA
5 .bss 00001000 000000000c00a000 000000000c00a000 00209384 2**5
ALLOC
6 .debug_info 000035be 0000000000000000 0000000000000000 00209384 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
7 .debug_abbrev 00000db5 0000000000000000 0000000000000000 0020c942 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
8 .debug_loclists 00006865 0000000000000000 0000000000000000 0020d6f7 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
9 .debug_aranges 000001b0 0000000000000000 0000000000000000 00213f5c 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
10 .debug_rnglists 0000059a 0000000000000000 0000000000000000 0021410c 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
11 .debug_line 00002046 0000000000000000 0000000000000000 002146a6 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
12 .debug_str 000005f3 0000000000000000 0000000000000000 002166ec 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
13 .debug_line_str 0000015c 0000000000000000 0000000000000000 00216cdf 2**0
CONTENTS, READONLY, DEBUGGING, OCTETS
It shouldn't be the alignment since its aligned to 0x1000, not 0x200000.
Now the problem is: What is the space 0x78 (end of the headders) to 0x200000 used for? thats a whole 2 Mib wasted! (yea it's a lot compared to that i only reserved 512 Mib of memory for my kernel)
Here is a reduced version of my makefile:
C_SOURCES = $(wildcard lib/*.c) $(wildcard libc/*.c)
HEADERS = $(wildcard include/*.h) $(wildcard include/kernel/*.h)
OBJ = ${C_SOURCES:.c=.o} lib/idtr.o asmlib/memmove.o asmlib/memcpy.o asmlib/unalignedisfaster.o asmlib/instrset.o \
asmlib/cputype.o asmlib/cachesize64.o
CFLAGS = -O2 -std=gnu11 -g -static -Wall -Wextra -Werror -Wno-unused-function \
-Wno-unused-parameter -nostartfiles -Wno-unused-but-set-variable \
-Wstrict-prototypes -Wpointer-arith -Wcast-align -Wwrite-strings -Wshadow \
-fno-stack-protector -Wundef -nostdlib -fno-builtin -nodefaultlibs \
-fms-extensions -ffreestanding -mcmodel=large -fverbose-asm -nostartfiles \
-mno-red-zone -mno-mmx -mno-sse -mno-sse2 -Iinclude -Wfloat-equal
all: kernel.bin
kernel.bin: lib/kernel_start.o ${OBJ}
x86_64-elf-gcc -o $# $^ -T link.ld -ffreestanding -O2 -nostdlib -lgcc
%.o: %.c
x86_64-elf-gcc ${CFLAGS} -c $< -o $#
%.o: %.asm
nasm $< -f elf64 -o $#
for the full makefile you can look here https://github.com/cheyao/AchieveOS/blob/master/Makefile

Answer 1

Thanks to Michal Petch in their comment, the solution is to add -z max-page-size=0x1000 to the compiler flags