diff --git a/src/system/boot/arch/arm/arch_cpu.cpp b/src/system/boot/arch/arm/arch_cpu.cpp
index 5bb64e59ab..fdd6d07297 100644
--- a/src/system/boot/arch/arm/arch_cpu.cpp
+++ b/src/system/boot/arch/arm/arch_cpu.cpp
@@ -123,13 +123,6 @@ arch_cpu_memory_write_barrier(void)
 }
 
 
-extern "C" void
-arch_spin(bigtime_t microseconds)
-{
-	panic("No timing support in bootloader yet!");
-}
-
-
 extern "C" status_t
 boot_arch_cpu_init(void)
 {
@@ -144,3 +137,21 @@ boot_arch_cpu_init(void)
 
 	return B_OK;
 }
+
+
+extern "C" bigtime_t
+system_time()
+{
+	#warning Implement system_time in ARM bootloader!
+	return 0;
+}
+
+
+extern "C" void
+spin(bigtime_t microseconds)
+{
+	#warning Implment spin in ARM bootloader!
+	//bigtime_t time = system_time();
+	//while ((system_time() - time) < microseconds)
+	//	asm volatile ("nop;");
+}
diff --git a/src/system/boot/arch/arm/arch_cpu.h b/src/system/boot/arch/arm/arch_cpu.h
index beebacb359..f904cf2e01 100644
--- a/src/system/boot/arch/arm/arch_cpu.h
+++ b/src/system/boot/arch/arm/arch_cpu.h
@@ -13,7 +13,6 @@
 extern "C" {
 #endif
 
-extern void arch_spin(bigtime_t microseconds);
 extern void arch_cpu_memory_read_barrier(void);
 extern void arch_cpu_memory_write_barrier(void);
 extern status_t boot_arch_cpu_init(void);
diff --git a/src/system/boot/platform/efi/arch/arm/crt0-efi-arm.S b/src/system/boot/platform/efi/arch/arm/crt0-efi-arm.S
index c5bb6d482d..817d8a775b 100644
--- a/src/system/boot/platform/efi/arch/arm/crt0-efi-arm.S
+++ b/src/system/boot/platform/efi/arch/arm/crt0-efi-arm.S
@@ -69,7 +69,7 @@ extra_header_fields:
 	// Everything before the kernel image is considered part of the header
 	.long	_start - ImageBase		// SizeOfHeaders
 	.long	0				// CheckSum
-	.short	EFI_SUBSYSTEM			// Subsystem
+	.short	10				// Subsystem (EFI)
 	.short	0				// DllCharacteristics
 	.long	0				// SizeOfStackReserve
 	.long	0				// SizeOfStackCommit
@@ -122,6 +122,7 @@ section_table:
 	.short	0		// NumberOfLineNumbers  (0 for executables)
 	.long	0xe0500020	// Characteristics (section flags)
 
+	.globl _start
 _start:
 	stmfd		sp!, {r0-r2, lr}
 
diff --git a/src/system/boot/platform/efi/arch/arm64/crt0-efi-arm64.S b/src/system/boot/platform/efi/arch/arm64/crt0-efi-arm64.S
index c300d89bdf..481bdb40e1 100644
--- a/src/system/boot/platform/efi/arch/arm64/crt0-efi-arm64.S
+++ b/src/system/boot/platform/efi/arch/arm64/crt0-efi-arm64.S
@@ -67,7 +67,7 @@ extra_header_fields:
 	// Everything before the kernel image is considered part of the header
 	.long	_start - ImageBase		// SizeOfHeaders
 	.long	0				// CheckSum
-	.short	EFI_SUBSYSTEM			// Subsystem
+	.short	10				// Subsystem (EFI)
 	.short	0				// DllCharacteristics
 	.quad	0				// SizeOfStackReserve
 	.quad	0				// SizeOfStackCommit
@@ -110,6 +110,8 @@ section_table:
 	.long	0xc0000040	// Characteristics (section flags)
 
 	.align		12
+
+	.globl _start
 _start:
 	stp		x29, x30, [sp, #-32]!
 	mov		x29, sp
diff --git a/src/system/boot/platform/u-boot/arch/ppc/arch_cpu.cpp b/src/system/boot/platform/u-boot/arch/ppc/arch_cpu.cpp
index 68c338e8f5..dff416c268 100644
--- a/src/system/boot/platform/u-boot/arch/ppc/arch_cpu.cpp
+++ b/src/system/boot/platform/u-boot/arch/ppc/arch_cpu.cpp
@@ -257,7 +257,7 @@ check_cpu_features()
 
 
 extern "C" void
-arch_spin(bigtime_t microseconds)
+spin(bigtime_t microseconds)
 {
 	for(bigtime_t i=0;i<microseconds;i=i+1)
 	{
diff --git a/src/system/boot/platform/u-boot/cpu.cpp b/src/system/boot/platform/u-boot/cpu.cpp
index 96c4265552..a4e601e20b 100644
--- a/src/system/boot/platform/u-boot/cpu.cpp
+++ b/src/system/boot/platform/u-boot/cpu.cpp
@@ -26,17 +26,6 @@
 #endif
 
 
-extern "C" void
-spin(bigtime_t microseconds)
-{
-	#warning U-Boot:TODO!!
-	// TODO: use API if available
-
-	// fallback to arch-specific code
-	arch_spin(microseconds);
-}
-
-
 extern "C" void
 cpu_init()
 {
diff --git a/src/system/boot/platform/u-boot/cpu.h b/src/system/boot/platform/u-boot/cpu.h
index dd9de74e55..66523a6bec 100644
--- a/src/system/boot/platform/u-boot/cpu.h
+++ b/src/system/boot/platform/u-boot/cpu.h
@@ -13,7 +13,6 @@
 extern "C" {
 #endif
 
-extern void arch_spin(bigtime_t microseconds);
 extern status_t boot_arch_cpu_init(void);
 extern void cpu_init(void);
 
diff --git a/src/system/ldscripts/arm/boot_loader_efi.ld b/src/system/ldscripts/arm/boot_loader_efi.ld
index 6851c1f821..22a734a84a 100644
--- a/src/system/ldscripts/arm/boot_loader_efi.ld
+++ b/src/system/ldscripts/arm/boot_loader_efi.ld
@@ -55,6 +55,8 @@ SECTIONS
   . = ALIGN(4096);
   .dynstr   : { *(.dynstr) }
   . = ALIGN(4096);
+
+  _end = . ;
   .note.gnu.build-id : { *(.note.gnu.build-id) }
   /DISCARD/ :
   {
diff --git a/src/system/ldscripts/riscv64/boot_loader_efi.ld b/src/system/ldscripts/riscv64/boot_loader_efi.ld
index aece030c37..455ba0dff9 100644
--- a/src/system/ldscripts/riscv64/boot_loader_efi.ld
+++ b/src/system/ldscripts/riscv64/boot_loader_efi.ld
@@ -61,6 +61,8 @@ SECTIONS
 	. = ALIGN(4096);
 	.dynstr   : { *(.dynstr) }
 	. = ALIGN(4096);
+
+	_end = . ;
 	.note.gnu.build-id : { *(.note.gnu.build-id) }
 	/DISCARD/ : {
 		*(.rel.reloc)