zephyr build overview官方说明文档: https://docs.zephyrproject.org/latest/guides/build/index.html
zephyr 也同样采用了设备树来描述板级信息，实际使用上zephyr并不是像linux那样用dtc编译成dtb然后代码中去解析dtb,从官方文档可以看出，zephyr会把dts最终转变成head file来使用的，其中过程如下:
1. c预处理器处理include dtsi 和define的预处理，这一步与linux kernel的编译同样，生成的*.dts.pre.tmp 文件可以用dtc编译成dtb，在zephyr中并没有使用dtb，所以只用来debug
2. dts/bindings 有设备的yaml后缀文件，yaml文件其实也是一种配置文件类型，类似ini，json配置文件，cmake/dts.cmake 调用scripts/dts/extract_dts_includes.py 脚本处理yaml文件生成dedicatee_unfixed.h，链接文章解释了这个转化过程https://docs.zephyrproject.org/latest/guides/dts/macros.html?highlight=yaml。
本地代码举例
yaml：
properties:
compatible:
constraint: "nxp,s32k-flexcan"
reg:
type: array
description: register base address
generation: define
category: required
interrupts:
type: array
category: required
description: required interrupts
generation: define
interrupt-names:
type: array
category: optional
description: names off the interrupt lines
*dts.pre.tmp：
can0: can0@40024000 {
compatible = "nxp,s32k-flexcan";
reg = <0x40024000 0x1000>;
interrupts = <78 0>, <79 0>, <80 0>, <81 0>, <82 0>;
interrupt-names = "ORed", "Error", "Wake_Up", "ORed_0_15_MB", "ORed_16_31_MB";
clocks = <&s32k_cc 52 0x0>;
label = "CAN_0";
bus-speed = <500000>;
};
*dts_unfixed.h：
/* can0@40024000 */
#define DT_NXP_S32K_FLEXCAN_0 1
#define DT_NXP_S32K_FLEXCAN_40024000_BASE_ADDRESS 0x40024000
#define DT_NXP_S32K_FLEXCAN_40024000_BUS_SPEED 500000
#define DT_NXP_S32K_FLEXCAN_40024000_CLOCK_CONTROLLER "S32K_CC"
#define DT_NXP_S32K_FLEXCAN_40024000_CLOCK_NAME_0 52
#define DT_NXP_S32K_FLEXCAN_40024000_CLOCK_RETAIN_0 0
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_0 78
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_0_PRIORITY 0
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_1 79
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_1_PRIORITY 0
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_2 80
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_2_PRIORITY 0
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_3 81
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_3_PRIORITY 0
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_4 82
#define DT_NXP_S32K_FLEXCAN_40024000_IRQ_4_PRIORITY 0
3.west -v build * samples/hello_world 2>&1 |tee make.log，能看到kconfig的处理过程的log，处理kconfig的脚本在script/kconfig/kconfig.py
Parsing Kconfig tree in west_zephyr/zephyr/Kconfig
Loading west_zephyr/zephyr/boards/arm/xxx/xxx_defconfig as base
Merging west_zephyr/zephyr/samples/hello_world/prj.conf
Configuration written to 'west_zephyr/zephyr/build/zephyr/.config'
这步Merging的顺序是prj.conf在后面，所以prj.conf的CONFIG的值会覆盖defconfig中的值
以samples/helloworld 举例，在prj.conf中定义CONFIG_DEBUG=n,build出来的autoconf.h就没有DEBUG的config配置项，尽管xxx_defconfig中CONFIG_DEBUG=y
4. dts & kconfig headfile的使用
include/arch/arm/arch.h
-->#include <generated_dts_board.h>
-->#include <generated_dts_board_fixups.h>
autoconf.h
Cmakelist.txt 中zephyr_compile_options 中添加编译选项 -imacros $(AUTOCONF_H)，从gcc官网查到这个选项是预处理选项，可以获取到指定文件中的所有定义define，所以不用再include 本文见就可以吃到这些CONFIG
-imacros file
Exactly like -include, except that any output produced by scanning file is thrown away. Macros it defines remain defined. This allows you to acquire all the macros from a header without also processing its declarations.
All files specified by -imacros are processed before all files specified by -include.
未找到答案
1.devicetree_fixups.h fixup是个什么过程
已解决, dts_fixup.h 在soc/arm/xxx目录下，用来对DTS补充一些define，最后会把这些define一起合并到build/zephyr/include/generated/generated_dts_board_fixups.h中