diff --git a/kernel/arch/earm/pre_init.c b/kernel/arch/earm/pre_init.c
index 646fb4556..a54f1d3e9 100644
--- a/kernel/arch/earm/pre_init.c
+++ b/kernel/arch/earm/pre_init.c
@@ -105,7 +105,6 @@ int overlaps(multiboot_module_t *mod, int n, int cmp_mod)
 #define MB_MODS_BASE  0x82000000
 #define MB_PARAM_MOD  0x88000000
 #define MB_MODS_ALIGN 0x00800000 /* 8 MB */
-#define MB_MODS_SIZE  0x00400000 /* 4 MB */
 #define MB_MMAP_START 0x80000000
 #define MB_MMAP_SIZE  0x10000000 /* 256 MB */
 
@@ -123,7 +122,8 @@ void setup_mbi(multiboot_info_t *mbi)
 	int i;
 	for (i = 0; i < MB_MODS_NR; ++i) {
 	    mb_modlist[i].mod_start = MB_MODS_BASE + i * MB_MODS_ALIGN;
-	    mb_modlist[i].mod_end = mb_modlist[i].mod_start + MB_MODS_SIZE ;
+	    mb_modlist[i].mod_end = mb_modlist[i].mod_start + MB_MODS_ALIGN
+		- ARM_PAGE_SIZE;
 	    mb_modlist[i].cmdline = 0;
 	}
 
diff --git a/lib/libc/arch/arm/sys-minix/ucontext.S b/lib/libc/arch/arm/sys-minix/ucontext.S
index 9fd6c7ed2..23e951026 100644
--- a/lib/libc/arch/arm/sys-minix/ucontext.S
+++ b/lib/libc/arch/arm/sys-minix/ucontext.S
@@ -126,9 +126,6 @@ ENTRY(setcontext)
 	pop {r0, r3}
 
 1:	/* Restore the registers */
-	ldr r1,  [r0, #REG1]		/* Restore r1 */
-	ldr r2,  [r0, #REG2]		/* Restore r2 */
-	ldr r3,  [r0, #REG3]		/* Restore r3 */
 	ldr r4,  [r0, #REG4]		/* Restore r4 */
 	ldr r5,  [r0, #REG5]		/* Restore r5 */
 	ldr r6,  [r0, #REG6]		/* Restore r6 */
@@ -140,10 +137,10 @@ ENTRY(setcontext)
 	ldr fp,  [r0, #FPREG]		/* Restore fp */
 	ldr sp,  [r0, #SPREG]		/* Restore sp */
 	ldr lr,  [r0, #LRREG]		/* Restore lr */
-	mov r4, r0
-	ldr r0,  [r4, #REG0]		/* Restore r0 */
+	mov r3, r0
+	ldr r0,  [r3, #REG0]		/* Restore r0 */
 2:
-	ldr pc,  [r4, #PCREG]		/* Restore pc */
+	ldr pc,  [r3, #PCREG]		/* Restore pc */
 
 
 /* void ctx_start()
diff --git a/servers/vfs/tll.c b/servers/vfs/tll.c
index 93c2ea7fa..c7fa0de1b 100644
--- a/servers/vfs/tll.c
+++ b/servers/vfs/tll.c
@@ -125,11 +125,13 @@ void tll_init(tll_t *tllp)
 
 int tll_islocked(tll_t *tllp)
 {
+  assert(tllp >= (tll_t *) PAGE_SIZE);
   return(tllp->t_current != TLL_NONE);
 }
 
 int tll_locked_by_me(tll_t *tllp)
 {
+  assert(tllp >= (tll_t *) PAGE_SIZE);
   assert(self != NULL);
   return(tllp->t_owner == self && !(tllp->t_status & TLL_PEND));
 }
@@ -139,7 +141,7 @@ int tll_lock(tll_t *tllp, tll_access_t locktype)
 /* Try to lock three-level-lock tll with type locktype */
 
   assert(self != NULL);
-  assert(tllp != NULL);
+  assert(tllp >= (tll_t *) PAGE_SIZE);
   assert(locktype != TLL_NONE);
 
   self->w_next = NULL;