Revert "x86: reserve the first megabyte"

This reverts commit 51e3c9efa5.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

arch/x86/core/x86_mmu.c

@@ -17,7 +17,6 @@
 #include <x86_mmu.h>
 #include <init.h>
 #include <kernel_internal.h>
-#include <mmu.h>
 #include <drivers/interrupt_controller/loapic.h>
 
 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
@@ -1776,22 +1775,3 @@ void z_x86_current_stack_perms(void)
 #endif
 }
 #endif /* CONFIG_USERSPACE */
-
-#ifdef CONFIG_ARCH_HAS_RESERVED_PAGE_FRAMES
-/* Selected on PC-like targets at the SOC level.
- *
- * Best is to do some E820 or similar enumeration to specifically identify
- * all page frames which are reserved by the hardware or firmware.
- *
- * For now, just reserve everything in the first megabyte of physical memory.
- */
-void arch_reserved_pages_update(void)
-{
-	for (uintptr_t pos = 0; pos < (1024 * 1024);
-	     pos += CONFIG_MMU_PAGE_SIZE) {
-		struct z_page_frame *pf = z_phys_to_page_frame(pos);
-
-		pf->flags |= Z_PAGE_FRAME_RESERVED;
-	}
-}
-#endif /* CONFIG_ARCH_HAS_RESERVED_PAGE_FRAMES */

soc/x86/apollo_lake/Kconfig.soc

@@ -10,4 +10,3 @@ config SOC_APOLLO_LAKE
 	select PCIE_MSI
 	select DYNAMIC_INTERRUPTS
 	select X86_MMU
-	select ARCH_HAS_RESERVED_PAGE_FRAMES

soc/x86/atom/Kconfig.soc

@@ -6,4 +6,3 @@ config SOC_ATOM
 	select CPU_ATOM
 	select X86_MMU
 	select ARCH_HAS_USERSPACE
-	select ARCH_HAS_RESERVED_PAGE_FRAMES

soc/x86/ia32/Kconfig.soc

@@ -4,4 +4,3 @@ config SOC_IA32
 	bool "Generic IA32 SoC"
 	select X86
 	select CPU_MINUTEIA
-	select ARCH_HAS_RESERVED_PAGE_FRAMES if SRAM_BASE_ADDRESS = 0