x86: linker: define z_mapped_* symbols

We will use this to map the kernel instead of all RAM.
The end of the kernel is always page-aligned, regardless
of CONFIG_SRAM_REGION_PERMISSIONS as it must be mapped.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

include/arch/x86/ia32/linker.ld

@@ -51,14 +51,20 @@
 	#define RAMABLE_REGION RAM
 #endif
 
+#ifdef CONFIG_MMU
+	#define MMU_PAGE_ALIGN		. = ALIGN(CONFIG_MMU_PAGE_SIZE);
+#else
+	#define MMU_PAGE_ALIGN
+#endif
+
 /* Used to align areas with separate memory permission characteristics
  * so that the page permissions can be set in the MMU. Without this,
  * the kernel is just one blob with the same RWX permissions on all RAM
  */
 #ifdef CONFIG_SRAM_REGION_PERMISSIONS
-	#define MMU_PAGE_ALIGN	. = ALIGN(CONFIG_MMU_PAGE_SIZE);
+	#define MMU_PAGE_ALIGN_PERM	MMU_PAGE_ALIGN
 #else
-	#define MMU_PAGE_ALIGN
+	#define MMU_PAGE_ALIGN_PERM
 #endif
 
 ENTRY(CONFIG_KERNEL_ENTRY)
@@ -90,6 +96,9 @@ SECTIONS
 	SECTION_PROLOGUE(_TEXT_SECTION_NAME,,)
 	{
 	_image_text_start = .;
+#ifndef CONFIG_XIP
+	z_mapped_start = .;
+#endif
 
 /* Located in generated directory. This file is populated by calling
  * zephyr_linker_sources(ROM_START ...). This typically contains the vector
@@ -112,7 +121,7 @@ SECTIONS
 
 #include <linker/kobject-text.ld>
 
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 	} GROUP_LINK_IN(ROMABLE_REGION)
 
 	_image_text_end = .;
@@ -156,7 +165,7 @@ SECTIONS
 
 #include <linker/cplusplus-rom.ld>
 
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 	/* ROM ends here, position counter will now be in RAM areas */
 #ifdef CONFIG_XIP
 	_image_rom_end = .;
@@ -177,6 +186,10 @@ SECTIONS
 	/* RAMABLE_REGION */
 	GROUP_START(RAMABLE_REGION)
 
+#ifdef CONFIG_XIP
+	MMU_PAGE_ALIGN
+	z_mapped_start = .;
+#endif
 /* Located in generated directory. This file is populated by the
  * zephyr_linker_sources() Cmake function.
  */
@@ -184,8 +197,8 @@ SECTIONS
 
 #ifdef CONFIG_USERSPACE
 	/* APP SHARED MEMORY REGION */
-#define SMEM_PARTITION_ALIGN(size) MMU_PAGE_ALIGN
+#define SMEM_PARTITION_ALIGN(size) MMU_PAGE_ALIGN_PERM
-#define APP_SHARED_ALIGN  MMU_PAGE_ALIGN
+#define APP_SHARED_ALIGN  MMU_PAGE_ALIGN_PERM
 
 #include <app_smem.ld>
 
@@ -198,7 +211,7 @@ SECTIONS
 
 	SECTION_PROLOGUE(_BSS_SECTION_NAME, (NOLOAD),)
 	{
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 #if !defined(CONFIG_USERSPACE)
 	_image_ram_start = .;
 #endif
@@ -227,7 +240,7 @@ SECTIONS
 
 #include <linker/common-noinit.ld>
 
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 
 	SECTION_DATA_PROLOGUE(_DATA_SECTION_NAME,,)
 	{
@@ -261,7 +274,7 @@ SECTIONS
 #include <snippets-rwdata.ld>
 
 #ifdef CONFIG_X86_KPTI
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 	z_shared_kernel_page_start = .;
 	/* Special page containing supervisor data that is still mapped in
 	 * user mode page tables. IDT, GDT, TSSes, trampoline stack, and
@@ -302,7 +315,7 @@ SECTIONS
 
 #ifdef CONFIG_X86_KPTI
 	z_trampoline_stack_start = .;
-	MMU_PAGE_ALIGN
+	MMU_PAGE_ALIGN_PERM
 	z_trampoline_stack_end = .;
 	z_shared_kernel_page_end = .;
 
@@ -334,6 +347,8 @@ SECTIONS
 	_image_ram_end = .;
 	_image_ram_all = (KERNEL_BASE_ADDR + KERNEL_RAM_SIZE) - _image_ram_start;
 
+	z_mapped_end = .;
+	z_mapped_size = z_mapped_end - z_mapped_start;
 	_end = .; /* end of image */
 
 	GROUP_END(RAMABLE_REGION)

include/arch/x86/intel64/linker.ld

@@ -70,7 +70,7 @@ SECTIONS
 	       "shared kernel area is not one memory page");
 #endif /* CONFIG_X86_KPTI */
 
-	MMU_PAGE_ALIGN
+	. = ALIGN(CONFIG_MMU_PAGE_SIZE);
 	_lodata_end = .;
 	} > LOCORE
 
@@ -87,6 +87,7 @@ SECTIONS
 	{
 	_image_rom_start = .;
 	_image_text_start = .;
+	z_mapped_start = .;
 	*(.text)
 	*(.text.*)
 
@@ -179,14 +180,17 @@ SECTIONS
 
 /* Must be last in RAM */
 #include <linker/kobject.ld>
-
+	. = ALIGN(CONFIG_MMU_PAGE_SIZE);
 	_image_ram_end = .;
+	z_mapped_end = .;
 	_end = .;
 
 	/* All unused memory also owned by the kernel for heaps */
 	__kernel_ram_end = KERNEL_BASE_ADDR + KERNEL_RAM_SIZE;
 	__kernel_ram_size = __kernel_ram_end - __kernel_ram_start;
 
+	z_mapped_size = z_mapped_end - z_mapped_start;
+
 #include <linker/debug-sections.ld>
 
 	/DISCARD/ :