[U-Boot] [RFC 2/3] ARM: WIP: add flat device tree support

Grant Likely grant.likely at secretlab.ca
Tue Aug 10 21:44:41 CEST 2010


On Thu, Aug 5, 2010 at 4:14 PM, John Rigby <john.rigby at linaro.org> wrote:
> Add device tree support for ARM.  Based on other existing
> implementations.

Hi John,

minor comments.

>
> Signed-off-by: John Rigby <john.rigby at linaro.org>
> ---
>  arch/arm/include/asm/config.h |    1 +
>  arch/arm/lib/bootm.c          |  128 ++++++++++++++++++++++++++++++++++++++++-
>  common/cmd_bootm.c            |    5 +-
>  common/image.c                |    7 ++-
>  include/image.h               |    2 +-
>  5 files changed, 138 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
> index b76fd8e..9bca5bc 100644
> --- a/arch/arm/include/asm/config.h
> +++ b/arch/arm/include/asm/config.h
> @@ -23,5 +23,6 @@
>
>  /* Relocation to SDRAM works on all ARM boards */
>  #define CONFIG_RELOC_FIXUP_WORKS
> +#define CONFIG_LMB
>
>  #endif
> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
> index 3101321..e45d974 100644
> --- a/arch/arm/lib/bootm.c
> +++ b/arch/arm/lib/bootm.c
> @@ -27,6 +27,12 @@
>  #include <u-boot/zlib.h>
>  #include <asm/byteorder.h>
>
> +#if defined(CONFIG_OF_LIBFDT)
> +#include <fdt.h>
> +#include <libfdt.h>
> +#include <fdt_support.h>
> +#endif
> +

Can these be included unconditionally?  Will they hurt anything when
CONFIG_OF_LIBFDT is not selected?  (and if they do, maybe the headers
themselves should be fixed to be safe)

>  DECLARE_GLOBAL_DATA_PTR;
>
>  #if defined (CONFIG_SETUP_MEMORY_TAGS) || \
> @@ -50,7 +56,34 @@ static void setup_end_tag (bd_t *bd);
>  static struct tag *params;
>  #endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */
>
> -int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
> +static ulong get_sp(void);
> +#if defined(CONFIG_OF_LIBFDT)
> +static int bootm_linux_fdt(bootm_headers_t *images);
> +#endif
> +
> +void arch_lmb_reserve(struct lmb *lmb)
> +{
> +       ulong sp;
> +
> +       /*
> +        * Booting a (Linux) kernel image
> +        *
> +        * Allocate space for command line and board info - the
> +        * address should be as high as possible within the reach of
> +        * the kernel (see CONFIG_SYS_BOOTMAPSZ settings), but in unused
> +        * memory, which means far enough below the current stack
> +        * pointer.
> +        */
> +       sp = get_sp();
> +       debug("## Current stack ends at 0x%08lx ", sp);
> +
> +       /* adjust sp by 1K to be safe */
> +       sp -= 1024;
> +       lmb_reserve(lmb, sp,
> +                   gd->bd->bi_dram[0].start + gd->bd->bi_dram[0].size - sp);
> +}
> +
> +int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
>  {
>        bd_t    *bd = gd->bd;
>        char    *s;
> @@ -64,6 +97,11 @@ int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *ima
>        if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
>                return 1;
>
> +#ifdef CONFIG_OF_LIBFDT
> +       if (images->ft_len)
> +               return bootm_linux_fdt(images);
> +#endif
> +
>        theKernel = (void (*)(int, int, uint))images->ep;
>
>        s = getenv ("machid");
> @@ -99,7 +137,7 @@ int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *ima
>        if (images->rd_start && images->rd_end)
>                setup_initrd_tag (bd, images->rd_start, images->rd_end);
>  #endif
> -       setup_end_tag (bd);
> +       setup_end_tag(bd);
>  #endif
>
>        /* we assume that the kernel is in place */
> @@ -120,6 +158,84 @@ int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *ima
>        return 1;
>  }
>
> +#if defined(CONFIG_OF_LIBFDT)
> +static int fixup_memory_node(void *blob)
> +{
> +       bd_t    *bd = gd->bd;
> +       int bank;
> +       u64 start[CONFIG_NR_DRAM_BANKS];
> +       u64 size[CONFIG_NR_DRAM_BANKS];
> +
> +       for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
> +               start[bank] = bd->bi_dram[bank].start;
> +               size[bank] = bd->bi_dram[bank].size;
> +       }
> +
> +       return fdt_fixup_memory_banks(blob, start, size, CONFIG_NR_DRAM_BANKS);
> +}
> +
> +static int bootm_linux_fdt(bootm_headers_t *images)
> +{
> +       ulong rd_len;
> +       bd_t *bd = gd->bd;
> +       char *s;
> +       int machid = bd->bi_arch_number;
> +       void (*theKernel)(int zero, int dt_machid, void *dtblob);
> +       ulong bootmap_base = getenv_bootm_low();
> +       ulong of_size = images->ft_len;
> +       char **of_flat_tree = &images->ft_addr;
> +       ulong *initrd_start = &images->initrd_start;
> +       ulong *initrd_end = &images->initrd_end;
> +       struct lmb *lmb = &images->lmb;
> +       int ret;
> +
> +       theKernel = (void (*)(int, int, void *))images->ep;

U-Boot naming convention is lowercase with underscores, just like the kernel.

> +
> +       s = getenv("machid");
> +       if (s) {
> +               machid = simple_strtoul(s, NULL, 16);
> +               printf("Using machid 0x%x from environment\n", machid);
> +       }
> +
> +       show_boot_progress(15);
> +
> +       rd_len = images->rd_end - images->rd_start;
> +       ret = boot_ramdisk_high(lmb, images->rd_start, rd_len,
> +                               initrd_start, initrd_end);
> +       if (ret)
> +               return ret;
> +
> +       ret = boot_relocate_fdt(lmb, bootmap_base, of_flat_tree, &of_size);
> +       if (ret)
> +               return ret;
> +
> +       debug("## Transferring control to Linux (at address %08lx) ...\n",
> +              (ulong) theKernel);
> +
> +       fdt_chosen(*of_flat_tree, 1);
> +
> +       fixup_memory_node(*of_flat_tree);
> +
> +       fdt_initrd(*of_flat_tree, *initrd_start, *initrd_end, 1);
> +
> +       /* we assume that the kernel is in place */
> +       printf("\nStarting kernel ...\n\n");
> +
> +#ifdef CONFIG_USB_DEVICE
> +       {
> +               extern void udc_disconnect(void);
> +               udc_disconnect();
> +       }
> +#endif
> +
> +       cleanup_before_linux();
> +
> +       theKernel(0, machid, *of_flat_tree);
> +       /* does not return */
> +
> +       return 1;
> +}
> +#endif
>
>  #if defined (CONFIG_SETUP_MEMORY_TAGS) || \
>     defined (CONFIG_CMDLINE_TAG) || \
> @@ -239,4 +355,12 @@ static void setup_end_tag (bd_t *bd)
>        params->hdr.size = 0;
>  }
>
> +static ulong get_sp(void)
> +{
> +       ulong ret;
> +
> +       asm("mov %0, sp" : "=r"(ret) : );
> +       return ret;
> +}
> +
>  #endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */
> diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
> index 594bccb..c6207cf 100644
> --- a/common/cmd_bootm.c
> +++ b/common/cmd_bootm.c
> @@ -301,7 +301,10 @@ static int bootm_start(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]
>                }
>
>  #if defined(CONFIG_OF_LIBFDT)
> -#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_SPARC)
> +#if defined(CONFIG_PPC) || \
> +    defined(CONFIG_M68K) || \
> +    defined(CONFIG_SPARC) || \
> +    defined(CONFIG_ARM)

There's got to be a better way to do this.  :-)  Are there other
architectures from PPC, M68K and SPARC that have OF_LIBFDT set?

>                /* find flattened device tree */
>                ret = boot_get_fdt (flag, argc, argv, &images,
>                                    &images.ft_addr, &images.ft_len);
> diff --git a/common/image.c b/common/image.c
> index 6d8833e..6da38aa 100644
> --- a/common/image.c
> +++ b/common/image.c
> @@ -985,7 +985,10 @@ int boot_get_ramdisk (int argc, char * const argv[], bootm_headers_t *images,
>        return 0;
>  }
>
> -#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_SPARC)
> +#if defined(CONFIG_PPC) || \
> +    defined(CONFIG_M68K) || \
> +    defined(CONFIG_SPARC) || \
> +    defined(CONFIG_ARM)
>  /**
>  * boot_ramdisk_high - relocate init ramdisk
>  * @lmb: pointer to lmb handle, will be used for memory mgmt
> @@ -1206,9 +1209,11 @@ int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base,
>        if (fdt_blob < (char *)bootmap_base)
>                relocate = 1;
>
> +#ifdef CONFIG_SYS_BOOTMAPSZ
>        if ((fdt_blob + *of_size + CONFIG_SYS_FDT_PAD) >=
>                        ((char *)CONFIG_SYS_BOOTMAPSZ + bootmap_base))
>                relocate = 1;
> +#endif
>
>        /* move flattend device tree if needed */
>        if (relocate) {
> diff --git a/include/image.h b/include/image.h
> index bcc08d1..8f06cdc 100644
> --- a/include/image.h
> +++ b/include/image.h
> @@ -339,7 +339,7 @@ int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base,
>                char **of_flat_tree, ulong *of_size);
>  #endif
>
> -#if defined(CONFIG_PPC) || defined(CONFIG_M68K)
> +#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_ARM)
>  int boot_ramdisk_high (struct lmb *lmb, ulong rd_data, ulong rd_len,
>                  ulong *initrd_start, ulong *initrd_end);
>
> --
> 1.7.0.4
>
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>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.


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