[Qemu-devel] [rfc 3/3] arm : make initrd load address dynamic

[Daniel Lezcano <daniel.lezcano@free.fr>]

Instead of hardcoding a default value for initrd, let's compute
dynamically from the kernel load address and its size.
We go one page after the end of the kernel.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
---
 hw/arm-misc.h |    1 +
 hw/arm_boot.c |   19 ++++++++-----------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/hw/arm-misc.h b/hw/arm-misc.h
index 010acb4..e72f87e 100644
--- a/hw/arm-misc.h
+++ b/hw/arm-misc.h
@@ -34,6 +34,7 @@ struct arm_boot_info {
     int (*atag_board)(struct arm_boot_info *info, void *p);
     /* Used internally by arm_boot.c */
     int is_linux;
+    target_phys_addr_t initrd_load_addr;
     target_phys_addr_t initrd_size;
     target_phys_addr_t entry;
 };
diff --git a/hw/arm_boot.c b/hw/arm_boot.c
index 16a33af..638ef62 100644
--- a/hw/arm_boot.c
+++ b/hw/arm_boot.c
@@ -15,7 +15,6 @@
 
 #define KERNEL_ARGS_ADDR 0x100
 #define KERNEL_LOAD_ADDR 0x00010000
-#define INITRD_LOAD_ADDR 0x00800000
 
 /* The worlds second smallest bootloader.  Set r0-r2, then jump to kernel.  */
 static uint32_t bootloader[] = {
@@ -71,7 +70,7 @@ static void set_kernel_args(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->loader_start + info->initrd_load_addr);
         WRITE_WORD(p, initrd_size);
     }
     if (info->kernel_cmdline && *info->kernel_cmdline) {
@@ -147,7 +146,7 @@ static void set_kernel_args_old(struct arm_boot_info *info)
     WRITE_WORD(p, 0);
     /* initrd_start */
     if (initrd_size)
-        WRITE_WORD(p, info->loader_start + INITRD_LOAD_ADDR);
+        WRITE_WORD(p, info->loader_start + info->initrd_load_addr);
     else
         WRITE_WORD(p, 0);
     /* initrd_size */
@@ -201,6 +200,7 @@ void arm_load_kernel(CPUState *env, struct arm_boot_info *info)
     int is_linux = 0;
     uint64_t elf_entry;
     target_phys_addr_t entry;
+    target_phys_addr_t initrd_load_addr = 0x0;
     int big_endian;
 
     /* Load the kernel.  */
@@ -242,16 +242,13 @@ void arm_load_kernel(CPUState *env, struct arm_boot_info *info)
     if (is_linux) {
         if (info->initrd_filename) {
 
-            if (KERNEL_LOAD_ADDR + kernel_size >= INITRD_LOAD_ADDR) {
-		    fprintf(stderr, "qemu: kernel is too big: %d Bytes\n",
-			    kernel_size);
-		    exit(1);
-	    }
-
+	    initrd_load_addr = KERNEL_LOAD_ADDR + kernel_size +
+		    TARGET_PAGE_SIZE;
+	    initrd_load_addr = TARGET_PAGE_ALIGN(initrd_load_addr);
             initrd_size = load_image_targphys(info->initrd_filename,
                                               info->loader_start
-                                              + INITRD_LOAD_ADDR,
-                                              ram_size - INITRD_LOAD_ADDR);
+                                              + initrd_load_addr,
+                                              ram_size - initrd_load_addr);
             if (initrd_size < 0) {
                 fprintf(stderr, "qemu: could not load initrd '%s'\n",
                         info->initrd_filename);
-- 
1.7.0.4