Unexpected value for the linker script variables - c

Question

I am trying to write my own linker script.
The current version is here:
MEMORY
{
ROM (rx) : ORIGIN = 0x00000000, LENGTH = 0x00004000
RAM (rwx) : ORIGIN = 0x00004000, LENGTH = 0x00004000
}
STACK_SIZE = 0x3000;
BOOT_PC = 0x1000;
/* Section Definitions */
SECTIONS
{
/* Code and constants */
.text :
{
*(.rodata*);
KEEP(*(.vectors .vectors.*));
. = BOOT_PC;
KEEP(*start.o(.text*));
*(.text*);
_etext = . ;
_idata = . ;
} > ROM
/* Unitialized data */
.bss (NOLOAD) :
{
_sbss = . ;
*(.bss*);
*(COMMON);
_ebss = . ;
} > RAM
/* Initialized data */
.data : AT(_idata)
{
_sdata = . ;
*(.data*);
_edata = . ;
} > RAM
/* Stack */
.stack (NOLOAD):
{
. = ALIGN(8);
. = . + STACK_SIZE;
. = ALIGN(8);
_stack = . ;
} > RAM
}
In my C program, I have global variables which are supposed to go in .bss (foo) and .data(init, a1 and a2) sections:
int foo;
int init = 4;
int a1 = 4;
int a2 = 4;
When I use objdump, I have the following result:
elf/noste.elf: file format elf32-littleriscv
SYMBOL TABLE:
00000000 l d .text 00000000 .text
00004000 l d .sbss 00000000 .sbss
00004004 l d .sdata 00000000 .sdata
00004010 l d .stack 00000000 .stack
00000000 l d .comment 00000000 .comment
00000000 l d .riscv.attributes 00000000 .riscv.attributes
00000000 l df *ABS* 00000000 start.o
0000103c l .text 00000000 _end_trigger
00001050 l .text 00000000 _end_loop
00000000 l df *ABS* 00000000 main.c
00000000 l df *ABS* 00000000 reset.c
0000105c g F .text 0000008c reset_handler
00003000 g *ABS* 00000000 STACK_SIZE
000010e8 g .text 00000000 _etext
00004000 g .text 00000000 _sbss
00004008 g O .sdata 00000004 a1
00004004 g .sdata 00000000 _sdata
00004000 g .text 00000000 _ebss
000010e8 g .text 00000000 _idata
00001000 g .text 00000000 _start
0000400c g O .sdata 00000004 init
00001054 g F .text 00000008 main
00004004 g O .sdata 00000004 a2
00004000 g O .sbss 00000004 foo
00004004 g .sdata 00000000 _edata
0000103c g .text 00000000 _end
00007010 g .stack 00000000 _stack
00001000 g *ABS* 00000000 BOOT_PC
As expected, the different C variables are placed in the .sbss and .sdata sections.
However, _ebss and _edata are not incremented and have the same value than _sbss and _sdata.
Instead of _ebss = 00004000 and _edata = 00004004, I expected _ebss = 00004004 and _edata = 00004010.
An idea about my issue here ?
Thanks for the help.