diff --git a/include/arch/x86/arch/kernel/boot_sys.h b/include/arch/x86/arch/kernel/boot_sys.h
index 01114968b..e2aba15a2 100644
--- a/include/arch/x86/arch/kernel/boot_sys.h
+++ b/include/arch/x86/arch/kernel/boot_sys.h
@@ -14,6 +14,30 @@
 #include <arch/kernel/multiboot.h>
 #include <arch/kernel/multiboot2.h>
 
+/* type definitions (directly corresponding to abstract specification) */
+typedef struct boot_state {
+    p_region_t   avail_p_reg; /* region of available physical memory on platform */
+    p_region_t   ki_p_reg;    /* region where the kernel image is in */
+    ui_info_t    ui_info;     /* info about userland images */
+    uint32_t     num_ioapic;  /* number of IOAPICs detected */
+    paddr_t      ioapic_paddr[CONFIG_MAX_NUM_IOAPIC];
+    uint32_t     num_drhu; /* number of IOMMUs */
+    paddr_t      drhu_list[MAX_NUM_DRHU]; /* list of physical addresses of the IOMMUs */
+    acpi_rmrr_list_t rmrr_list;
+    acpi_rsdp_t  acpi_rsdp; /* copy of the rsdp */
+    paddr_t      mods_end_paddr; /* physical address where boot modules end */
+    paddr_t      boot_module_start; /* physical address of first boot module */
+    uint32_t     num_cpus;    /* number of detected cpus */
+    uint32_t     mem_lower;   /* lower memory size for boot code of APs to run in real mode */
+    cpu_id_t     cpus[CONFIG_MAX_NUM_NODES];
+    mem_p_regs_t mem_p_regs;  /* physical memory regions */
+    seL4_X86_BootInfo_VBE vbe_info; /* Potential VBE information from multiboot */
+    seL4_X86_BootInfo_mmap_t mb_mmap_info; /* memory map information from multiboot */
+    seL4_X86_BootInfo_fb_t fb_info; /* framebuffer information as set by bootloader */
+} boot_state_t;
+
+extern boot_state_t boot_state;
+
 void boot_sys(
     unsigned long multiboot_magic,
     void *multiboot
diff --git a/src/arch/x86/kernel/boot_sys.c b/src/arch/x86/kernel/boot_sys.c
index f348d437a..5d5358f27 100644
--- a/src/arch/x86/kernel/boot_sys.c
+++ b/src/arch/x86/kernel/boot_sys.c
@@ -53,29 +53,6 @@ extern char _start[1];
 
 #define HIGHMEM_PADDR 0x100000
 
-/* type definitions (directly corresponding to abstract specification) */
-
-typedef struct boot_state {
-    p_region_t   avail_p_reg; /* region of available physical memory on platform */
-    p_region_t   ki_p_reg;    /* region where the kernel image is in */
-    ui_info_t    ui_info;     /* info about userland images */
-    uint32_t     num_ioapic;  /* number of IOAPICs detected */
-    paddr_t      ioapic_paddr[CONFIG_MAX_NUM_IOAPIC];
-    uint32_t     num_drhu; /* number of IOMMUs */
-    paddr_t      drhu_list[MAX_NUM_DRHU]; /* list of physical addresses of the IOMMUs */
-    acpi_rmrr_list_t rmrr_list;
-    acpi_rsdp_t  acpi_rsdp; /* copy of the rsdp */
-    paddr_t      mods_end_paddr; /* physical address where boot modules end */
-    paddr_t      boot_module_start; /* physical address of first boot module */
-    uint32_t     num_cpus;    /* number of detected cpus */
-    uint32_t     mem_lower;   /* lower memory size for boot code of APs to run in real mode */
-    cpu_id_t     cpus[CONFIG_MAX_NUM_NODES];
-    mem_p_regs_t mem_p_regs;  /* physical memory regions */
-    seL4_X86_BootInfo_VBE vbe_info; /* Potential VBE information from multiboot */
-    seL4_X86_BootInfo_mmap_t mb_mmap_info; /* memory map information from multiboot */
-    seL4_X86_BootInfo_fb_t fb_info; /* framebuffer information as set by bootloader */
-} boot_state_t;
-
 BOOT_BSS
 boot_state_t boot_state;