Re: [PATCH 16/17] lib: support libxbc

On 11/26/22 11:59, Safae Ouajih wrote:

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This adds support for libxbc used to support Bootconfig feature. Bootconfig documentation : [1] This was imported from [2], commit [3]

This should be written something like

This was adapted from downstream [2] commit 7af0a0506d4 ("shortlog summary").

[1] https://source.android.com/docs/core/architecture/bootloader/implementing-bo... [2] https://android.googlesource.com/platform/external/u-boot/ [3] `7af0a0506d4de6f5ea147d10fb0664a8af07d326`

Signed-off-by: Safae Ouajih souajih@baylibre.com

include/xbc.h | 1 + lib/Kconfig | 12 +++++ lib/Makefile | 1 + lib/libxbc/Makefile | 1 + lib/libxbc/libxbc.c | 112 ++++++++++++++++++++++++++++++++++++++++++++ lib/libxbc/libxbc.h | 54 +++++++++++++++++++++ 6 files changed, 181 insertions(+) create mode 100644 include/xbc.h create mode 100644 lib/libxbc/Makefile create mode 100644 lib/libxbc/libxbc.c create mode 100644 lib/libxbc/libxbc.h

I understand that you may want to import this "library" directly, but it is really so short that I question the virtue of this. I think it would be better to convert this to U-Boot style.

--Sean

diff --git a/include/xbc.h b/include/xbc.h new file mode 100644 index 000000000000..725e65ff6ad8 --- /dev/null +++ b/include/xbc.h @@ -0,0 +1 @@ +#include <../lib/libxbc/libxbc.h> diff --git a/lib/Kconfig b/lib/Kconfig index 6abe1d0a863b..eca752b7db79 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -417,6 +417,18 @@ config LIBAVB

endmenu

+menu "Android Boot Configuration" +config LIBXBC

•   bool "Android Boot Configuration support"
  

•   depends on ANDROID_BOOT_IMAGE
  

•   default n
  

•   help
  

•     This enables support of Boot Configuration which can be used
  

•     to pass boot configuration parameters to user space. These
  

•     parameters will show up in /proc/bootconfig similar to the kernel
  

•     parameters that show up in /proc/cmdline
  

+endmenu

menu "Hashing Support"

config BLAKE2 diff --git a/lib/Makefile b/lib/Makefile index f2cfd1e42892..b0ad522ac116 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -87,6 +87,7 @@ obj-$(CONFIG_$(SPL_)LZ4) += lz4_wrapper.o obj-$(CONFIG_$(SPL_)LIB_RATIONAL) += rational.o

obj-$(CONFIG_LIBAVB) += libavb/ +obj-$(CONFIG_LIBXBC) += libxbc/

obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += libfdt/ obj-$(CONFIG_$(SPL_TPL_)OF_REAL) += fdtdec_common.o fdtdec.o diff --git a/lib/libxbc/Makefile b/lib/libxbc/Makefile new file mode 100644 index 000000000000..7ac4cde05666 --- /dev/null +++ b/lib/libxbc/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_LIBXBC) += libxbc.o diff --git a/lib/libxbc/libxbc.c b/lib/libxbc/libxbc.c new file mode 100644 index 000000000000..129bffc7c628 --- /dev/null +++ b/lib/libxbc/libxbc.c @@ -0,0 +1,112 @@ +/*

• • Copyright (C) 2021 The Android Open Source Project
• • Licensed under the Apache License, Version 2.0 (the "License");
• • you may not use this file except in compliance with the License.
• • You may obtain a copy of the License at

• •  http://www.apache.org/licenses/LICENSE-2.0
    

• • Unless required by applicable law or agreed to in writing, software
• • distributed under the License is distributed on an "AS IS" BASIS,
• • WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
• • See the License for the specific language governing permissions and
• • limitations under the License.
• */

+#include "libxbc.h" +#define BOOTCONFIG_MAGIC "#BOOTCONFIG\n" +#define BOOTCONFIG_MAGIC_SIZE 12 +#define BOOTCONFIG_SIZE_SIZE 4 +#define BOOTCONFIG_CHECKSUM_SIZE 4 +#define BOOTCONFIG_TRAILER_SIZE BOOTCONFIG_MAGIC_SIZE + \

•                            BOOTCONFIG_SIZE_SIZE + \
  

•                            BOOTCONFIG_CHECKSUM_SIZE
  

+/*

• • Simple checksum for a buffer.
• • @param addr pointer to the start of the buffer.
• • @param size size of the buffer in bytes.
• • @return check sum result.
• */

+static uint32_t checksum(const unsigned char* const buffer, uint32_t size) {

• uint32_t sum = 0;
• for (uint32_t i = 0; i < size; i++) {

•    sum += buffer[i];
  

• }
• return sum;

+}

+/*

• • Check if the bootconfig trailer is present within the bootconfig section.
• • @param bootconfig_end_addr address of the end of the bootconfig section. If

• •    the trailer is present, it will be directly preceding this address.
    

• • @return true if the trailer is present, false if not.
• */

+static bool isTrailerPresent(uint64_t bootconfig_end_addr) {

• return !strncmp((char*)(bootconfig_end_addr - BOOTCONFIG_MAGIC_SIZE),

•                BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_SIZE);
  

+}

+/*

• • Add a string of boot config parameters to memory appended by the trailer.
• */

+int32_t addBootConfigParameters(char* params, uint32_t params_size,

• uint64_t bootconfig_start_addr, uint32_t bootconfig_size) {
• if (!params || !bootconfig_start_addr) {

•    return -1;
  

• }
• if (params_size == 0) {

•    return 0;
  

• }
• int32_t applied_bytes = 0;
• int32_t new_size = 0;
• uint64_t end = bootconfig_start_addr + bootconfig_size;
• if (isTrailerPresent(end)) {

•  end -= BOOTCONFIG_TRAILER_SIZE;
  

•  applied_bytes -= BOOTCONFIG_TRAILER_SIZE;
  

•  memcpy(&new_size, (void *)end, BOOTCONFIG_SIZE_SIZE);
  

• } else {

•  new_size = bootconfig_size;
  

• }
• // params
• memcpy((void*)end, params, params_size);
• applied_bytes += params_size;
• applied_bytes += addBootConfigTrailer(bootconfig_start_addr,

•    bootconfig_size + applied_bytes);
  

• return applied_bytes;

+}

+/*

• • Add boot config trailer.
• */

+int32_t addBootConfigTrailer(uint64_t bootconfig_start_addr,

•                        uint32_t bootconfig_size) {
  

• if (!bootconfig_start_addr) {

•    return -1;
  

• }
• if (bootconfig_size == 0) {

•    return 0;
  

• }
• uint64_t end = bootconfig_start_addr + bootconfig_size;
• if (isTrailerPresent(end)) {

•    return 0;
  

• }
• // size
• memcpy((void *)(end), &bootconfig_size, BOOTCONFIG_SIZE_SIZE);
• // checksum
• uint32_t sum = checksum((unsigned char*)bootconfig_start_addr, bootconfig_size);
• memcpy((void *)(end + BOOTCONFIG_SIZE_SIZE), &sum, BOOTCONFIG_CHECKSUM_SIZE);
• // magic
• memcpy((void *)(end + BOOTCONFIG_SIZE_SIZE + BOOTCONFIG_CHECKSUM_SIZE),

•       BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_SIZE);
  

• return BOOTCONFIG_TRAILER_SIZE;

+} diff --git a/lib/libxbc/libxbc.h b/lib/libxbc/libxbc.h new file mode 100644 index 000000000000..0b6ba4960905 --- /dev/null +++ b/lib/libxbc/libxbc.h @@ -0,0 +1,54 @@ +/*

• • Copyright (C) 2021 The Android Open Source Project
• • Licensed under the Apache License, Version 2.0 (the "License");
• • you may not use this file except in compliance with the License.
• • You may obtain a copy of the License at

• •  http://www.apache.org/licenses/LICENSE-2.0
    

• • Unless required by applicable law or agreed to in writing, software
• • distributed under the License is distributed on an "AS IS" BASIS,
• • WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
• • See the License for the specific language governing permissions and
• • limitations under the License.
• */

+#ifndef LIBXBC_H_ +#define LIBXBC_H_

+#include <common.h> +/*

• • Add a string of boot config parameters to memory appended by the trailer.
• • This memory needs to be immediately following the end of the ramdisks.
• • The new boot config trailer will be written to the end of the entire
• • parameter section(previous + new). The trailer contains a 4 byte size of the
• • parameters, followed by a 4 byte checksum of the parameters, followed by a 12
• • byte magic string.
• • @param params pointer to string of boot config parameters
• • @param params_size size of params string in bytes
• • @param bootconfig_start_addr address that the boot config section is starting

• •    at in memory.
    

• • @param bootconfig_size size of the current bootconfig section in bytes.
• • @return number of bytes added to the boot config section. -1 for error.
• */

+int addBootConfigParameters(char *params, uint32_t params_size,

•                        uint64_t bootconfig_start_addr,
  

•                        uint32_t bootconfig_size);
  

+/*

• • Add the boot config trailer to the end of the boot config parameter section.
• • This can be used after the vendor bootconfig section has been placed into
• • memory if there are no additional parameters that need to be added.
• • The new boot config trailer will be written to the end of the entire
• • parameter section at (bootconfig_start_addr + bootconfig_size).
• • The trailer contains a 4 byte size of the parameters, followed by a 4 byte
• • checksum of the parameters, followed by a 12 byte magic string.
• • @param bootconfig_start_addr address that the boot config section is starting

• •    at in memory.
    

• • @param bootconfig_size size of the current bootconfig section in bytes.
• • @return number of bytes added to the boot config section. -1 for error.
• */

+int addBootConfigTrailer(uint64_t bootconfig_start_addr,

•                     uint32_t bootconfig_size);
  

+#endif /* LIBXBC_H_ */

2.25.1