Re: [Qemu-devel] [PATCH 4/4] ppc4xx: load Bamboo kernel, initrd, and fdt at fixed addresses

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Wed, Aug 04, 2010 at 05:21:37PM -0700, Hollis Blanchard wrote:
> We can't use the return value of load_uimage() for the kernel because it
> can't account for BSS size, and the PowerPC kernel does not relocate
> blobs before zeroing BSS.
> 
> Instead, we now load at the fixed addresses chosen by u-boot (the normal
> firmware for the board).
> 
> Signed-off-by: Hollis Blanchard <hollis@penguinppc.org>


This looks good to me, thanks Hollis.

Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>


> 
> ---
>  hw/ppc440_bamboo.c |   39 ++++++++++++++++++---------------------
>  1 files changed, 18 insertions(+), 21 deletions(-)
> 
> This fixes a critical bug in PowerPC 440 Bamboo board emulation.
> 
> diff --git a/hw/ppc440_bamboo.c b/hw/ppc440_bamboo.c
> index d471d5d..34ddf45 100644
> --- a/hw/ppc440_bamboo.c
> +++ b/hw/ppc440_bamboo.c
> @@ -27,6 +27,11 @@
>  
>  #define BINARY_DEVICE_TREE_FILE "bamboo.dtb"
>  
> +/* from u-boot */
> +#define KERNEL_ADDR  0x1000000
> +#define FDT_ADDR     0x1800000
> +#define RAMDISK_ADDR 0x1900000
> +
>  static int bamboo_load_device_tree(target_phys_addr_t addr,
>                                       uint32_t ramsize,
>                                       target_phys_addr_t initrd_base,
> @@ -98,10 +103,8 @@ static void bamboo_init(ram_addr_t ram_size,
>      uint64_t elf_lowaddr;
>      target_phys_addr_t entry = 0;
>      target_phys_addr_t loadaddr = 0;
> -    target_long kernel_size = 0;
> -    target_ulong initrd_base = 0;
>      target_long initrd_size = 0;
> -    target_ulong dt_base = 0;
> +    int success;
>      int i;
>  
>      /* Setup CPU. */
> @@ -118,15 +121,15 @@ static void bamboo_init(ram_addr_t ram_size,
>  
>      /* Load kernel. */
>      if (kernel_filename) {
> -        kernel_size = load_uimage(kernel_filename, &entry, &loadaddr, NULL);
> -        if (kernel_size < 0) {
> -            kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry,
> -                                   &elf_lowaddr, NULL, 1, ELF_MACHINE, 0);
> +        success = load_uimage(kernel_filename, &entry, &loadaddr, NULL);
> +        if (success < 0) {
> +            success = load_elf(kernel_filename, NULL, NULL, &elf_entry,
> +                               &elf_lowaddr, NULL, 1, ELF_MACHINE, 0);
>              entry = elf_entry;
>              loadaddr = elf_lowaddr;
>          }
>          /* XXX try again as binary */
> -        if (kernel_size < 0) {
> +        if (success < 0) {
>              fprintf(stderr, "qemu: could not load kernel '%s'\n",
>                      kernel_filename);
>              exit(1);
> @@ -135,26 +138,20 @@ static void bamboo_init(ram_addr_t ram_size,
>  
>      /* Load initrd. */
>      if (initrd_filename) {
> -        initrd_base = kernel_size + loadaddr;
> -        initrd_size = load_image_targphys(initrd_filename, initrd_base,
> -                                          ram_size - initrd_base);
> +        initrd_size = load_image_targphys(initrd_filename, RAMDISK_ADDR,
> +                                          ram_size - RAMDISK_ADDR);
>  
>          if (initrd_size < 0) {
> -            fprintf(stderr, "qemu: could not load initial ram disk '%s'\n",
> -                    initrd_filename);
> +            fprintf(stderr, "qemu: could not load ram disk '%s' at %x\n",
> +                    initrd_filename, RAMDISK_ADDR);
>              exit(1);
>          }
>      }
>  
>      /* If we're loading a kernel directly, we must load the device tree too. */
>      if (kernel_filename) {
> -        if (initrd_base)
> -            dt_base = initrd_base + initrd_size;
> -        else
> -            dt_base = kernel_size + loadaddr;
> -
> -        if (bamboo_load_device_tree(dt_base, ram_size,
> -                        initrd_base, initrd_size, kernel_cmdline) < 0) {
> +        if (bamboo_load_device_tree(FDT_ADDR, ram_size, RAMDISK_ADDR,
> +                                    initrd_size, kernel_cmdline) < 0) {
>              fprintf(stderr, "couldn't load device tree\n");
>              exit(1);
>          }
> @@ -163,7 +160,7 @@ static void bamboo_init(ram_addr_t ram_size,
>  
>          /* Set initial guest state. */
>          env->gpr[1] = (16<<20) - 8;
> -        env->gpr[3] = dt_base;
> +        env->gpr[3] = FDT_ADDR;
>          env->nip = entry;
>          /* XXX we currently depend on KVM to create some initial TLB entries. */
>      }
> -- 
> 1.7.2
> 
>