diff --git a/hw/sun4m.c b/hw/sun4m.c
index 7db00b8222f65f616b2eadb04dfb4fe6e8fffdd6..ad1efb1ebc3eac429b57668b6e5c672a2b0d30da 100644
--- a/hw/sun4m.c
+++ b/hw/sun4m.c
@@ -917,6 +917,9 @@ static void sun4m_hw_init(const struct sun4m_hwdef *hwdef, ram_addr_t RAM_size,
     if (kernel_cmdline) {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, CMDLINE_ADDR);
         pstrcpy_targphys("cmdline", CMDLINE_ADDR, TARGET_PAGE_SIZE, kernel_cmdline);
+        fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA,
+                         (uint8_t*)strdup(kernel_cmdline),
+                         strlen(kernel_cmdline) + 1);
     } else {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, 0);
     }
@@ -1500,6 +1503,9 @@ static void sun4d_hw_init(const struct sun4d_hwdef *hwdef, ram_addr_t RAM_size,
     if (kernel_cmdline) {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, CMDLINE_ADDR);
         pstrcpy_targphys("cmdline", CMDLINE_ADDR, TARGET_PAGE_SIZE, kernel_cmdline);
+        fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA,
+                         (uint8_t*)strdup(kernel_cmdline),
+                         strlen(kernel_cmdline) + 1);
     } else {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, 0);
     }
@@ -1688,6 +1694,9 @@ static void sun4c_hw_init(const struct sun4c_hwdef *hwdef, ram_addr_t RAM_size,
     if (kernel_cmdline) {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, CMDLINE_ADDR);
         pstrcpy_targphys("cmdline", CMDLINE_ADDR, TARGET_PAGE_SIZE, kernel_cmdline);
+        fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA,
+                         (uint8_t*)strdup(kernel_cmdline),
+                         strlen(kernel_cmdline) + 1);
     } else {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, 0);
     }
diff --git a/hw/sun4u.c b/hw/sun4u.c
index a7a227bbec72df7edae30f1c7b5e16b73316300f..5cd67ee8bca10141a44fdc9e4a8d42cdbfcc5bde 100644
--- a/hw/sun4u.c
+++ b/hw/sun4u.c
@@ -652,6 +652,9 @@ static void sun4uv_init(ram_addr_t RAM_size,
     if (kernel_cmdline) {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, CMDLINE_ADDR);
         pstrcpy_targphys("cmdline", CMDLINE_ADDR, TARGET_PAGE_SIZE, kernel_cmdline);
+        fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA,
+                         (uint8_t*)strdup(kernel_cmdline),
+                         strlen(kernel_cmdline) + 1);
     } else {
         fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_CMDLINE, 0);
     }