diff --git a/hw/sharpsl.h b/hw/sharpsl.h
index 184aae6cdb..4d5cee98da 100644
--- a/hw/sharpsl.h
+++ b/hw/sharpsl.h
@@ -18,6 +18,6 @@ void scoop_gpio_out_set(struct scoop_info_s *s, int line,
                 qemu_irq handler);
 
 #define SL_PXA_PARAM_BASE	0xa0000a00
-void sl_bootparam_write(uint32_t ptr);
+void sl_bootparam_write(target_phys_addr_t ptr);
 
 #endif
diff --git a/hw/spitz.c b/hw/spitz.c
index ac844bddf7..6a15c78192 100644
--- a/hw/spitz.c
+++ b/hw/spitz.c
@@ -965,7 +965,7 @@ static void spitz_common_init(ram_addr_t ram_size, int vga_ram_size,
     spitz_binfo.initrd_filename = initrd_filename;
     spitz_binfo.board_id = arm_id;
     arm_load_kernel(cpu->env, &spitz_binfo);
-    sl_bootparam_write(SL_PXA_PARAM_BASE - PXA2XX_SDRAM_BASE);
+    sl_bootparam_write(SL_PXA_PARAM_BASE);
 }
 
 static void spitz_init(ram_addr_t ram_size, int vga_ram_size,
diff --git a/hw/tosa.c b/hw/tosa.c
index 6702b6b99a..55042e3515 100644
--- a/hw/tosa.c
+++ b/hw/tosa.c
@@ -239,7 +239,7 @@ static void tosa_init(ram_addr_t ram_size, int vga_ram_size,
     tosa_binfo.initrd_filename = initrd_filename;
     tosa_binfo.board_id = 0x208;
     arm_load_kernel(cpu->env, &tosa_binfo);
-    sl_bootparam_write(SL_PXA_PARAM_BASE - PXA2XX_SDRAM_BASE);
+    sl_bootparam_write(SL_PXA_PARAM_BASE);
 }
 
 QEMUMachine tosapda_machine = {
diff --git a/hw/zaurus.c b/hw/zaurus.c
index 8b16c47a41..482834fb7b 100644
--- a/hw/zaurus.c
+++ b/hw/zaurus.c
@@ -275,8 +275,8 @@ static struct __attribute__ ((__packed__)) sl_param_info {
     .phadadj		= 0x01,
 };
 
-void sl_bootparam_write(uint32_t ptr)
+void sl_bootparam_write(target_phys_addr_t ptr)
 {
-    memcpy(phys_ram_base + ptr, &zaurus_bootparam,
-                    sizeof(struct sl_param_info));
+    cpu_physical_memory_write(ptr, (void *)&zaurus_bootparam,
+                              sizeof(struct sl_param_info));
 }