arm: linker.ld: move bss section to ram end

fix bss section be copy to binary.

When compiling with non-xip.
All sections will be placed in the ram.
If NOBITS section isn't placed at the end of ram,
objcopy will placed these section to binary file.

The modify only for no-userspace.
In userspace the section will be adjust,
kobject_data size increase,
the bss be shifted, the content of kobject_data
will no mactch to kernel obj of bss.

Signed-off-by: Frank Li <lgl88911@163.com>

Author: lgl88911

include/arch/arm/aarch32/cortex_m/scripts/linker.ld

@@ -296,7 +296,6 @@ SECTIONS
 
 	_app_smem_size = _app_smem_end - _app_smem_start;
 	_app_smem_rom_start = LOADADDR(_APP_SMEM_SECTION_NAME);
-#endif  /* CONFIG_USERSPACE */
 
     SECTION_DATA_PROLOGUE(_BSS_SECTION_NAME,(NOLOAD),)
 	{
@@ -344,6 +343,8 @@ SECTIONS
 
         } GROUP_LINK_IN(RAMABLE_REGION)
 
+#endif  /* CONFIG_USERSPACE */
+
     SECTION_DATA_PROLOGUE(_DATA_SECTION_NAME,,)
 	{
 	__data_ram_start = .;
@@ -381,6 +382,53 @@ SECTIONS
 
     __data_ram_end = .;
 
+#ifndef CONFIG_USERSPACE
+   SECTION_DATA_PROLOGUE(_BSS_SECTION_NAME,(NOLOAD),)
+	{
+        /*
+         * For performance, BSS section is assumed to be 4 byte aligned and
+         * a multiple of 4 bytes
+         */
+        . = ALIGN(4);
+	__bss_start = .;
+	__kernel_ram_start = .;
+
+	*(.bss)
+	*(".bss.*")
+	*(COMMON)
+	*(".kernel_bss.*")
+
+#ifdef CONFIG_CODE_DATA_RELOCATION
+#include <linker_sram_bss_relocate.ld>
+#endif
+
+        /*
+         * As memory is cleared in words only, it is simpler to ensure the BSS
+         * section ends on a 4 byte boundary. This wastes a maximum of 3 bytes.
+		 */
+	__bss_end = ALIGN(4);
+	} GROUP_DATA_LINK_IN(RAMABLE_REGION, RAMABLE_REGION)
+
+    SECTION_PROLOGUE(_NOINIT_SECTION_NAME,(NOLOAD),)
+        {
+        /*
+         * This section is used for non-initialized objects that
+         * will not be cleared during the boot process.
+         */
+        *(.noinit)
+        *(".noinit.*")
+	*(".kernel_noinit.*")
+
+/* Located in generated directory. This file is populated by the
+ * zephyr_linker_sources() Cmake function.
+ */
+#include <snippets-noinit.ld>
+#ifdef CONFIG_SOC_NOINIT_LD
+#include <soc-noinit.ld>
+#endif
+
+        } GROUP_LINK_IN(RAMABLE_REGION)
+#endif /* CONFIG_USERSPACE */
 
     /* Define linker symbols */