arm_boot: Change initrd load address to "halfway through RAM"

[qemu.git] / hw / arm_boot.c

diff --git a/hw/arm_boot.c b/hw/arm_boot.c
index 09bf6c5cdc9048b1a992686d83abedb6ba692fae..92e2cab476fe2ca56799c7328077f8c5f558a578 100644 (file)
--- a/hw/arm_boot.c
+++ b/hw/arm_boot.c
@@ -18,7 +18,6 @@
 
 #define KERNEL_ARGS_ADDR 0x100
 #define KERNEL_LOAD_ADDR 0x00010000
-#define INITRD_LOAD_ADDR 0x00d00000
 
 /* The worlds second smallest bootloader.  Set r0-r2, then jump to kernel.  */
 static uint32_t bootloader[] = {
@@ -109,7 +108,7 @@ static void set_kernel_args(const struct arm_boot_info *info)
         /* ATAG_INITRD2 */
         WRITE_WORD(p, 4);
         WRITE_WORD(p, 0x54420005);
-        WRITE_WORD(p, info->loader_start + INITRD_LOAD_ADDR);
+        WRITE_WORD(p, info->initrd_start);
         WRITE_WORD(p, initrd_size);
     }
     if (info->kernel_cmdline && *info->kernel_cmdline) {
@@ -185,10 +184,11 @@ static void set_kernel_args_old(const struct arm_boot_info *info)
     /* pages_in_vram */
     WRITE_WORD(p, 0);
     /* initrd_start */
-    if (initrd_size)
-        WRITE_WORD(p, info->loader_start + INITRD_LOAD_ADDR);
-    else
+    if (initrd_size) {
+        WRITE_WORD(p, info->initrd_start);
+    } else {
         WRITE_WORD(p, 0);
+    }
     /* initrd_size */
     WRITE_WORD(p, initrd_size);
     /* rd_start */
@@ -281,14 +281,13 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
 
     if (binfo->initrd_size) {
         rc = qemu_devtree_setprop_cell(fdt, "/chosen", "linux,initrd-start",
-                binfo->loader_start + INITRD_LOAD_ADDR);
+                binfo->initrd_start);
         if (rc < 0) {
             fprintf(stderr, "couldn't set /chosen/linux,initrd-start\n");
         }
 
         rc = qemu_devtree_setprop_cell(fdt, "/chosen", "linux,initrd-end",
-                    binfo->loader_start + INITRD_LOAD_ADDR +
-                    binfo->initrd_size);
+                    binfo->initrd_start + binfo->initrd_size);
         if (rc < 0) {
             fprintf(stderr, "couldn't set /chosen/linux,initrd-end\n");
         }
@@ -375,6 +374,19 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     big_endian = 0;
 #endif
 
+    /* We want to put the initrd far enough into RAM that when the
+     * kernel is uncompressed it will not clobber the initrd. However
+     * on boards without much RAM we must ensure that we still leave
+     * enough room for a decent sized initrd, and on boards with large
+     * amounts of RAM we must avoid the initrd being so far up in RAM
+     * that it is outside lowmem and inaccessible to the kernel.
+     * So for boards with less  than 256MB of RAM we put the initrd
+     * halfway into RAM, and for boards with 256MB of RAM or more we put
+     * the initrd at 128MB.
+     */
+    info->initrd_start = info->loader_start +
+        MIN(info->ram_size / 2, 128 * 1024 * 1024);
+
     /* Assume that raw images are linux kernels, and ELF images are not.  */
     kernel_size = load_elf(info->kernel_filename, NULL, NULL, &elf_entry,
                            NULL, NULL, big_endian, ELF_MACHINE, 1);
@@ -398,10 +410,9 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     if (is_linux) {
         if (info->initrd_filename) {
             initrd_size = load_image_targphys(info->initrd_filename,
-                                              info->loader_start
-                                              + INITRD_LOAD_ADDR,
-                                              info->ram_size
-                                              - INITRD_LOAD_ADDR);
+                                              info->initrd_start,
+                                              info->ram_size -
+                                              info->initrd_start);
             if (initrd_size < 0) {
                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
                         info->initrd_filename);
@@ -419,9 +430,8 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
          */
         if (info->dtb_filename) {
             /* Place the DTB after the initrd in memory */
-            hwaddr dtb_start = TARGET_PAGE_ALIGN(info->loader_start
-                                                             + INITRD_LOAD_ADDR
-                                                             + initrd_size);
+            hwaddr dtb_start = TARGET_PAGE_ALIGN(info->initrd_start +
+                                                 initrd_size);
             if (load_dtb(dtb_start, info)) {
                 exit(1);
             }