device_tree: Add support for reading device tree properties

[qemu.git] / hw / arm_boot.c

diff --git a/hw/arm_boot.c b/hw/arm_boot.c
index d0e643ba11130ae6f23f3f84912584036b6c21c4..af71ed6c362473904258003e14d652dfbd708d25 100644 (file)
--- a/hw/arm_boot.c
+++ b/hw/arm_boot.c
@@ -242,10 +242,12 @@ static int load_dtb(target_phys_addr_t addr, const struct arm_boot_info *binfo)
         fprintf(stderr, "couldn't set /memory/reg\n");
     }
 
-    rc = qemu_devtree_setprop_string(fdt, "/chosen", "bootargs",
-                                      binfo->kernel_cmdline);
-    if (rc < 0) {
-        fprintf(stderr, "couldn't set /chosen/bootargs\n");
+    if (binfo->kernel_cmdline && *binfo->kernel_cmdline) {
+        rc = qemu_devtree_setprop_string(fdt, "/chosen", "bootargs",
+                                          binfo->kernel_cmdline);
+        if (rc < 0) {
+            fprintf(stderr, "couldn't set /chosen/bootargs\n");
+        }
     }
 
     if (binfo->initrd_size) {
@@ -355,7 +357,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     if (kernel_size < 0) {
         entry = info->loader_start + KERNEL_LOAD_ADDR;
         kernel_size = load_image_targphys(info->kernel_filename, entry,
-                                          ram_size - KERNEL_LOAD_ADDR);
+                                          info->ram_size - KERNEL_LOAD_ADDR);
         is_linux = 1;
     }
     if (kernel_size < 0) {
@@ -369,7 +371,8 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
             initrd_size = load_image_targphys(info->initrd_filename,
                                               info->loader_start
                                               + INITRD_LOAD_ADDR,
-                                              ram_size - INITRD_LOAD_ADDR);
+                                              info->ram_size
+                                              - INITRD_LOAD_ADDR);
             if (initrd_size < 0) {
                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
                         info->initrd_filename);
@@ -396,6 +399,12 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
             bootloader[5] = dtb_start;
         } else {
             bootloader[5] = info->loader_start + KERNEL_ARGS_ADDR;
+            if (info->ram_size >= (1ULL << 32)) {
+                fprintf(stderr, "qemu: RAM size must be less than 4GB to boot"
+                        " Linux kernel using ATAGS (try passing a device tree"
+                        " using -dtb)\n");
+                exit(1);
+            }
         }
         bootloader[6] = entry;
         for (n = 0; n < sizeof(bootloader) / 4; n++) {