原因
PL固件可能经常修改，而BOOT.BIN和文件系统、内核实际上基本不会变，在一个平台上可以用同一份。如果每次修改都要重新打包PL 固件到BOOT.BIN，操作起来非常麻烦。所以希望PL 的固件可以直接从指定位置加载。典型的可以从SD卡的FAT32分区加载。
https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841847/Solution+ZynqMP+PL+Programming
The Zynq UltraScale+ MPSoC Programmable Logic (PL) can be programmed either using First Stage Boot-loader(FSBL), U-Boot or through Linux.
这里主要是说U-BOOT的方式以及它存在的问题。
实施
修改platform-top.h，从platform-auto.h中copy 如下字段：
/* Extra U-Boot Env settings */
#define CONFIG_EXTRA_ENV_SETTINGS \
SERIAL_MULTI \
CONSOLE_ARG \
DFU_ALT_INFO_RAM \
DFU_ALT_INFO_MMC \
PSSERIAL0 \
"nc=setenv stdout nc;setenv stdin nc;\0" \
"ethaddr=00:0a:35:00:22:01\0" \
"bootenv=uEnv.txt\0" \
"importbootenv=echo \"Importing environment from SD ...\"; " \
"env import -t ${loadbootenv_addr} $filesize\0" \
"loadbootenv=load mmc $sdbootdev:$partid ${loadbootenv_addr} ${bootenv}\0" \
"sd_uEnvtxt_existence_test=test -e mmc $sdbootdev:$partid /uEnv.txt\0" \
"uenvboot=" \
"if run sd_uEnvtxt_existence_test; then " \
"run loadbootenv; " \
"echo Loaded environment from ${bootenv}; " \
"run importbootenv; " \
"fi; " \
"if test -n $uenvcmd; then " \
"echo Running uenvcmd ...; " \
"run uenvcmd; " \
"fi\0" \
"autoload=no\0" \
"sdbootdev=0\0" \
"clobstart=0x10000000\0" \
"netstart=0x10000000\0" \
"dtbnetstart=0x23fff000\0" \
"loadaddr=0x10000000\0" \
"boot_img=BOOT.BIN\0" \
"load_boot=tftpboot ${clobstart} ${boot_img}\0" \
"update_boot=setenv img boot; setenv psize ${bootsize}; setenv installcmd \"install_boot\"; run load_boot ${installcmd}; setenv img; setenv psize; setenv installcmd\0" \
"install_boot=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${boot_img} ${filesize}\0" \
"install_bootenv=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${bootenv_img} ${filesize}\0" \
"jffs2_img=rootfs.jffs2\0" \
"load_jffs2=tftpboot ${clobstart} ${jffs2_img}\0" \
"update_jffs2=setenv img jffs2; setenv psize ${jffs2size}; setenv installcmd \"install_jffs2\"; run load_jffs2 test_img; setenv img; setenv psize; setenv installcmd\0" \
"sd_update_jffs2=echo Updating jffs2 from SD; mmcinfo && fatload mmc ${sdbootdev}:1 ${clobstart} ${jffs2_img} && run install_jffs2\0" \
"install_jffs2=sf probe 0 && sf erase ${jffs2start} ${jffs2size} && " \
"sf write ${clobstart} ${jffs2start} ${filesize}\0" \
"kernel_img=image.ub\0" \
"load_kernel=tftpboot ${clobstart} ${kernel_img}\0" \
"update_kernel=setenv img kernel; setenv psize ${kernelsize}; setenv installcmd \"install_kernel\"; run load_kernel ${installcmd}; setenv img; setenv psize; setenv installcmd\0" \
"install_kernel=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${kernel_img} ${filesize}\0" \
"cp_kernel2ram=mmcinfo && fatload mmc ${sdbootdev} ${netstart} ${kernel_img}\0" \
"dtb_img=system.dtb\0" \
"load_dtb=tftpboot ${clobstart} ${dtb_img}\0" \
"update_dtb=setenv img dtb; setenv psize ${dtbsize}; setenv installcmd \"install_dtb\"; run load_dtb test_img; setenv img; setenv psize; setenv installcmd\0" \
"sd_update_dtb=echo Updating dtb from SD; mmcinfo && fatload mmc ${sdbootdev}:1 ${clobstart} ${dtb_img} && run install_dtb\0" \
"loadbootenv_addr=0x00100000\0" \
"fault=echo ${img} image size is greater than allocated place - partition ${img} is NOT UPDATED\0" \
"test_crc=if imi ${clobstart}; then run test_img; else echo ${img} Bad CRC - ${img} is NOT UPDATED; fi\0" \
"test_img=setenv var \"if test ${filesize} -gt ${psize}\\; then run fault\\; else run ${installcmd}\\; fi\"; run var; setenv var\0" \
"netboot=tftpboot ${netstart} ${kernel_img} && bootm\0" \
"default_bootcmd=run uenvboot; run cp_kernel2ram && bootm ${netstart}\0" \
""
COPY并增加烧录指令：
#define CONFIG_EXTRA_ENV_SETTINGS \
SERIAL_MULTI \
CONSOLE_ARG \
DFU_ALT_INFO_RAM \
DFU_ALT_INFO_MMC \
PSSERIAL0 \
"nc=setenv stdout nc;setenv stdin nc;\0" \
"ethaddr=00:0a:35:00:22:01\0" \
"bootenv=uEnv.txt\0" \
"importbootenv=echo \"Importing environment from SD ...\"; " \
"env import -t ${loadbootenv_addr} $filesize\0" \
"loadbootenv=load mmc $sdbootdev:$partid ${loadbootenv_addr} ${bootenv}\0" \
"sd_uEnvtxt_existence_test=test -e mmc $sdbootdev:$partid /uEnv.txt\0" \
"uenvboot=" \
"if run sd_uEnvtxt_existence_test; then " \
"run loadbootenv; " \
"echo Loaded environment from ${bootenv}; " \
"run importbootenv; " \
"fi; " \
"if test -n $uenvcmd; then " \
"echo Running uenvcmd ...; " \
"run uenvcmd; " \
"fi\0" \
"autoload=no\0" \
"sdbootdev=0\0" \
"clobstart=0x10000000\0" \
"netstart=0x10000000\0" \
"dtbnetstart=0x23fff000\0" \
"loadaddr=0x10000000\0" \
"bitstream_image=system.bit.bin\0" \
"mmc_loadbit_fat=echo Loading bistream from media to RAM..; && mmcinfo && fatload mmc ${sdbootdev} ${loadaddr} ${bitstream_image} && fpga load 0 ${loadaddr} ${filesize}\0" \
"boot_img=BOOT.BIN\0" \
"load_boot=tftpboot ${clobstart} ${boot_img}\0" \
"update_boot=setenv img boot; setenv psize ${bootsize}; setenv installcmd \"install_boot\"; run load_boot ${installcmd}; setenv img; setenv psize; setenv installcmd\0" \
"install_boot=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${boot_img} ${filesize}\0" \
"install_bootenv=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${bootenv_img} ${filesize}\0" \
"jffs2_img=rootfs.jffs2\0" \
"load_jffs2=tftpboot ${clobstart} ${jffs2_img}\0" \
"update_jffs2=setenv img jffs2; setenv psize ${jffs2size}; setenv installcmd \"install_jffs2\"; run load_jffs2 test_img; setenv img; setenv psize; setenv installcmd\0" \
"sd_update_jffs2=echo Updating jffs2 from SD; mmcinfo && fatload mmc ${sdbootdev}:1 ${clobstart} ${jffs2_img} && run install_jffs2\0" \
"install_jffs2=sf probe 0 && sf erase ${jffs2start} ${jffs2size} && " \
"sf write ${clobstart} ${jffs2start} ${filesize}\0" \
"kernel_img=image.ub\0" \
"load_kernel=tftpboot ${clobstart} ${kernel_img}\0" \
"update_kernel=setenv img kernel; setenv psize ${kernelsize}; setenv installcmd \"install_kernel\"; run load_kernel ${installcmd}; setenv img; setenv psize; setenv installcmd\0" \
"install_kernel=mmcinfo && fatwrite mmc ${sdbootdev} ${clobstart} ${kernel_img} ${filesize}\0" \
"cp_kernel2ram=mmcinfo && run mmc_loadbit_fat && fatload mmc ${sdbootdev} ${netstart} ${kernel_img}\0" \
"dtb_img=system.dtb\0" \
"load_dtb=tftpboot ${clobstart} ${dtb_img}\0" \
"update_dtb=setenv img dtb; setenv psize ${dtbsize}; setenv installcmd \"install_dtb\"; run load_dtb test_img; setenv img; setenv psize; setenv installcmd\0" \
"sd_update_dtb=echo Updating dtb from SD; mmcinfo && fatload mmc ${sdbootdev}:1 ${clobstart} ${dtb_img} && run install_dtb\0" \
"loadbootenv_addr=0x00100000\0" \
"fault=echo ${img} image size is greater than allocated place - partition ${img} is NOT UPDATED\0" \
"test_crc=if imi ${clobstart}; then run test_img; else echo ${img} Bad CRC - ${img} is NOT UPDATED; fi\0" \
"test_img=setenv var \"if test ${filesize} -gt ${psize}\\; then run fault\\; else run ${installcmd}\\; fi\"; run var; setenv var\0" \
"netboot=tftpboot ${netstart} ${kernel_img} && bootm\0" \
"default_bootcmd=run uenvboot; run cp_kernel2ram && bootm ${netstart}\0" \
""
其中主要增加 mmc_loadbit_fat 指令，指定u-boot 从指定位置加载指定的bit 文件。
这里bit文件实际上是bin 格式，这是因为bin 文件包含了头文件信息，这样ZYNQ才能完成PL编程。
BIT转BIN
cd [get_property DIRECTORY [current_project]]/[current_project].runs/impl_1
write_cfgmem -format bin -interface spix1 -loadbit "up 0x0 [get_property top [current_fileset]].bit" -file [get_property DIRECTORY [current_project]]/system.bit.bin -force
BIN文件放在BOOT.BIN和IMAGE.UB同目录
问题
如果你的PL 固件使用了PS的复位信号作为系统复位，这种方式可能会导致复位不完全导致逻辑故障。所以使用该方式要保证你的逻辑复位正常，这通常应该通过修改设计结局。
比如 我的CXP HOST采集和存储逻辑，当使用上述方式编程PL的时候会工作不正常，数据存储异常，但是直接打包到BOOT.BIN 通过FSBL加载则工作正常，这一点需要后续跟进debug ，这里也做一个记录。