[U-Boot] [PATCH v2 1/2] common: Add support for Android DT image

Alex Deymo deymo+ at google.com
Tue May 8 15:32:18 UTC 2018


Le jeu. 19 avr. 2018 à 22:52, Sam Protsenko <semen.protsenko at linaro.org> a
écrit :

> Android documentation recommends new image format for storing DTB/DTBO
> files: [1]. To support that format, two things should be done:
>
> 1. Add dt_table.h file from Android (BSD-3 relicensed version): [2].
>    This header defines structures and constants that we need to work
>    with that DT image format.
>
>    Changes:
>     - re-licensed from Apache to BSD-3
>
I'm not familiar with how you handle these re-licensing so I can't say
anything about that.


>     - removed functions declarations
>
You also removed DT_TABLE_DEFAULT_VERSION but left
DT_TABLE_DEFAULT_PAGE_SIZE, was that intentional?

    - change the coding style to kernel (make checkpatch happy)
>
> 2. Add helper functions for Android DTB/DTBO format. In
>    image-android-dt.* files you can find helper functions to work with
>    Android DT image format, such us routines for:
>     - printing the dump of image structure
>     - getting the address and size of desired dtb/dtbo file
>
> [1] https://source.android.com/devices/architecture/dto/partitions
> [2]
> https://android.googlesource.com/platform/system/libufdt/+/58a7582180f477032cd6c74f8d9afad0038e74c3/utils/src/dt_table.h
>
> Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
> ---
>  common/image-android-dt.c  | 157 +++++++++++++++++++++++++++++++++++++
>  include/dt_table.h         |  46 +++++++++++
>  include/image-android-dt.h |  21 +++++
>  3 files changed, 224 insertions(+)
>  create mode 100644 common/image-android-dt.c
>  create mode 100644 include/dt_table.h
>  create mode 100644 include/image-android-dt.h
>
> diff --git a/common/image-android-dt.c b/common/image-android-dt.c
> new file mode 100644
> index 0000000000..9b7683faab
> --- /dev/null
> +++ b/common/image-android-dt.c
> @@ -0,0 +1,157 @@
> +/*
> + * (C) Copyright 2018 Linaro Ltd.
> + * Sam Protsenko <semen.protsenko at linaro.org>
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#include <image-android-dt.h>
> +#include <dt_table.h>
> +#include <common.h>
> +#include <linux/libfdt.h>
> +#include <mapmem.h>
> +
> +/**
> + * Check if image header is correct.
> + *
> + * @param hdr_addr Start address of DT image
> + * @return true if header is correct or false if header is incorrect
> + */
> +bool android_dt_check_header(ulong hdr_addr)
> +{
> +       const struct dt_table_header *hdr;
> +       u32 magic;
> +
> +       hdr = map_sysmem(hdr_addr, sizeof(*hdr));
> +       magic = fdt32_to_cpu(hdr->magic);
> +       unmap_sysmem(hdr);
> +
> +       return magic == DT_TABLE_MAGIC;
> +}
> +
> +/**
> + * Get the address of FDT (dtb or dtbo) in memory by its index in image.
> + *
> + * @param hdr_addr Start address of DT image
> + * @param index Index of desired FDT in image (starting from 0)
> + * @param[out] addr If not NULL, will contain address to specified FDT
> + * @param[out] size If not NULL, will contain size of specified FDT
> + *
> + * @return true on success or false on error
> + */
> +bool android_dt_get_fdt_by_index(ulong hdr_addr, u32 index, ulong *addr,
> +                                u32 *size)
> +{
> +       const struct dt_table_header *hdr;
> +       const struct dt_table_entry *e;
> +       u32 entry_count, entries_offset, entry_size;
> +       ulong e_addr;
> +       u32 dt_offset, dt_size;
> +
> +       hdr = map_sysmem(hdr_addr, sizeof(*hdr));
> +       entry_count = fdt32_to_cpu(hdr->dt_entry_count);
> +       entries_offset = fdt32_to_cpu(hdr->dt_entries_offset);
> +       entry_size = fdt32_to_cpu(hdr->dt_entry_size);
> +       unmap_sysmem(hdr);
> +
> +       if (index > entry_count) {
> +               printf("Error: index > dt_entry_count (%u > %u)\n", index,
> +                      entry_count);
> +               return false;
> +       }
>
This function assumes the image is valid in several places, but here you
could also check that the relative offset you are going to load falls
within the the fdt32_to_cpu(hdr->total_size).

+
> +       e_addr = hdr_addr + entries_offset + index * entry_size;
> +       e = map_sysmem(e_addr, sizeof(*e));
> +       dt_offset = fdt32_to_cpu(e->dt_offset);
> +       dt_size = fdt32_to_cpu(e->dt_size);
> +       unmap_sysmem(e);
> +
> +       if (addr)
> +               *addr = hdr_addr + dt_offset;
> +       if (size)
> +               *size = dt_size;
> +
> +       return true;
> +}
> +
> +#if !defined(CONFIG_SPL_BUILD)
> +static void android_dt_print_fdt_info(const struct fdt_header *fdt)
> +{
> +       u32 fdt_size;
> +       int root_node_off;
> +       const char *compatible = NULL;
> +
> +       fdt_size = fdt_totalsize(fdt);
> +       root_node_off = fdt_path_offset(fdt, "/");
> +       if (root_node_off < 0) {
> +               printf("Error: Root node not found\n");
> +       } else {
> +               compatible = fdt_getprop(fdt, root_node_off, "compatible",
> +                                        NULL);
> +       }
> +
> +       printf("           (FDT)size = %d\n", fdt_size);
> +       printf("     (FDT)compatible = %s\n",
> +              compatible ? compatible : "(unknown)");
> +}
> +
> +/**
> + * Print information about DT image structure.
> + *
> + * @param hdr_addr Start address of DT image
> + */
> +void android_dt_print_contents(ulong hdr_addr)
> +{
> +       const struct dt_table_header *hdr;
> +       u32 entry_count, entries_offset, entry_size;
> +       u32 i;
> +
> +       hdr = map_sysmem(hdr_addr, sizeof(*hdr));
> +       entry_count = fdt32_to_cpu(hdr->dt_entry_count);
> +       entries_offset = fdt32_to_cpu(hdr->dt_entries_offset);
> +       entry_size = fdt32_to_cpu(hdr->dt_entry_size);
> +
> +       /* Print image header info */
> +       printf("dt_table_header:\n");
> +       printf("               magic = %08x\n", fdt32_to_cpu(hdr->magic));
> +       printf("          total_size = %d\n",
> fdt32_to_cpu(hdr->total_size));
> +       printf("         header_size = %d\n",
> fdt32_to_cpu(hdr->header_size));
> +       printf("       dt_entry_size = %d\n", entry_size);
> +       printf("      dt_entry_count = %d\n", entry_count);
> +       printf("   dt_entries_offset = %d\n", entries_offset);
> +       printf("           page_size = %d\n",
> fdt32_to_cpu(hdr->page_size));
> +       printf("         reserved[0] = %08x\n",
> fdt32_to_cpu(hdr->reserved[0]));
> +
> +       unmap_sysmem(hdr);
> +
> +       /* Print image entries info */
> +       for (i = 0; i < entry_count; ++i) {
> +               const ulong e_addr = hdr_addr + entries_offset + i *
> entry_size;
> +               const struct dt_table_entry *e;
> +               const struct fdt_header *fdt;
> +               u32 dt_offset, dt_size;
> +               u32 j;
> +
> +               e = map_sysmem(e_addr, sizeof(*e));
> +               dt_offset = fdt32_to_cpu(e->dt_offset);
> +               dt_size = fdt32_to_cpu(e->dt_size);
> +
> +               printf("dt_table_entry[%d]:\n", i);
> +               printf("             dt_size = %d\n", dt_size);
> +               printf("           dt_offset = %d\n", dt_offset);
> +               printf("                  id = %08x\n",
> fdt32_to_cpu(e->id));
> +               printf("                 rev = %08x\n",
> fdt32_to_cpu(e->rev));
> +               for (j = 0; j < 4; ++j) {
> +                       printf("           custom[%d] = %08x\n", j,
> +                              fdt32_to_cpu(e->custom[j]));
> +               }
> +
> +               unmap_sysmem(e);
> +
> +               /* Print FDT info for this entry */
> +               fdt = map_sysmem(hdr_addr + dt_offset, sizeof(*fdt));
> +               android_dt_print_fdt_info(fdt);
> +               unmap_sysmem(fdt);
> +       }
> +}
> +#endif
> diff --git a/include/dt_table.h b/include/dt_table.h
> new file mode 100644
> index 0000000000..19cbbeab2a
> --- /dev/null
> +++ b/include/dt_table.h
> @@ -0,0 +1,46 @@
> +/*
> + * This is from the Android Project,
> + * Repository: https://android.googlesource.com/platform/system/libufdt
> + * File: utils/src/dt_table.h
> + * Commit: 58a7582180f477032cd6c74f8d9afad0038e74c3
> + * Copyright (C) 2017 The Android Open Source Project
> + *
> + * SPDX-License-Identifier: BSD-3-Clause
> + */
> +
> +#ifndef DT_TABLE_H
> +#define DT_TABLE_H
> +
> +#include <linux/types.h>
> +
> +#define DT_TABLE_MAGIC                 0xd7b7ab1e
> +#define DT_TABLE_DEFAULT_PAGE_SIZE     2048
> +
> +struct dt_table_header {
> +       u32 magic;              /* DT_TABLE_MAGIC */
> +       u32 total_size;         /* includes dt_table_header + all
> dt_table_entry
> +                                * and all dtb/dtbo
> +                                */
> +       u32 header_size;        /* sizeof(dt_table_header) */
> +
> +       u32 dt_entry_size;      /* sizeof(dt_table_entry) */
> +       u32 dt_entry_count;     /* number of dt_table_entry */
> +       u32 dt_entries_offset;  /* offset to the first dt_table_entry
> +                                * from head of dt_table_header.
> +                                * The value will be equal to header_size
> if
> +                                * no padding is appended
> +                                */
> +       u32 page_size;          /* flash page size we assume */
> +       u32 reserved[1];        /* must be zero */
> +};
> +
> +struct dt_table_entry {
> +       u32 dt_size;
> +       u32 dt_offset;          /* offset from head of dt_table_header */
> +
> +       u32 id;                 /* optional, must be zero if unused */
> +       u32 rev;                /* optional, must be zero if unused */
> +       u32 custom[4];          /* optional, must be zero if unused */
> +};
> +
> +#endif
> diff --git a/include/image-android-dt.h b/include/image-android-dt.h
> new file mode 100644
> index 0000000000..08b810d461
> --- /dev/null
> +++ b/include/image-android-dt.h
> @@ -0,0 +1,21 @@
> +/*
> + * (C) Copyright 2018 Linaro Ltd.
> + * Sam Protsenko <semen.protsenko at linaro.org>
> + *
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#ifndef IMAGE_ANDROID_DT_H
> +#define IMAGE_ANDROID_DT_H
> +
> +#include <linux/types.h>
> +
> +bool android_dt_check_header(ulong hdr_addr);
> +bool android_dt_get_fdt_by_index(ulong hdr_addr, u32 index, ulong *addr,
> +                                u32 *size);
> +
> +#if !defined(CONFIG_SPL_BUILD)
> +void android_dt_print_contents(ulong hdr_addr);
> +#endif
> +
> +#endif /* IMAGE_ANDROID_DT_H */
> --
> 2.17.0
>

I haven't test this. Again, you probably want some maintainer to take a
look too.
Reviewed-by: Alex Deymo <deymo at google.com>

Regards,
Alex


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