Started building the kernel memory manager in userspace

sandbox/vm/Makefile

@@ -0,0 +1,2 @@
+include ../sandbox-config.mk
+include ../sandbox-template.mk

sandbox/vm/main.c

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+#include <stdio.h>
+#include <sys/mman.h>
+#include "vm.h"
+
+/* amount of memory to allocate for system RAM in megabytes */
+#define SIMULATED_MEMORY_MB 16
+
+#define MEMPTR(offset) ((void *)((uintptr_t)system_memory) + (offset))
+
+int main(int argc, const char **argv)
+{
+	printf("Hello, world!\n");
+
+	void *system_memory = mmap(
+			NULL,
+			SIMULATED_MEMORY_MB * 0x100000,
+			PROT_READ | PROT_WRITE,
+			MAP_PRIVATE | MAP_ANONYMOUS,
+			-1, 0);
+
+	if (system_memory == MAP_FAILED) {
+		perror("mmap");
+		fprintf(stderr, "cannot allocated simulated system RAM buffer\n");
+		return -1;
+	}
+
+	munmap(system_memory, SIMULATED_MEMORY_MB * 0x100000);
+	return 0;
+}

sandbox/vm/vm.h

@@ -0,0 +1,51 @@
+#ifndef SOCKS_VM_H_
+#define SOCKS_VM_H_
+
+#include <socks/types.h>
+
+/*******************************************
+ * Beginning of machine-specific definitions
+ *******************************************/
+typedef enum vm_zone_id {
+	VM_ZONE_DMA		= 0x01u,
+	VM_ZONE_NORMAL		= 0x02u,
+	VM_ZONE_HIGHMEM		= 0x03u,
+} vm_zone_id_t;
+/*******************************************
+ * End of machine-specific definitions.
+ *******************************************/
+
+typedef enum vm_memory_region_status {
+	VM_REGION_FREE		= 0x01u,
+	VM_REGION_RESERVED	= 0x02u,
+} vm_memory_region_status_t;
+
+typedef struct vm_zone_descriptor {
+	vm_zone_id_t zd_id;
+	phys_addr_t zd_base;
+	phys_addr_t zd_limit;
+} vm_zone_descriptor_t;
+
+typedef struct vm_zone {
+	unsigned z_reserved[32];
+} vm_zone_t;
+
+typedef struct vm_region {
+	vm_memory_region_status_t r_status;
+	phys_addr_t r_base;
+	phys_addr_t r_limit;
+} vm_region_t;
+
+typedef enum vm_page_flags {
+	VM_PAGE_RESERVED = 0x01u,
+} vm_page_flags_t;
+
+typedef struct vm_page {
+	uint32_t p_flags; /* vm_page_flags_t bitfield */
+} __attribute__((packed)) vm_page_t;
+
+extern void vm_bootstrap(void);
+
+extern void vm_page_init(vm_page_t *pg);
+
+#endif