1menu "ARM architecture" 2 depends on ARM 3 4config SYS_ARCH 5 default "arm" 6 7config ARM64 8 bool 9 10config HAS_VBAR 11 bool 12 13config HAS_THUMB2 14 bool 15 16config CPU_ARM720T 17 bool 18 19config CPU_ARM920T 20 bool 21 22config CPU_ARM926EJS 23 bool 24 25config CPU_ARM946ES 26 bool 27 28config CPU_ARM1136 29 bool 30 31config CPU_ARM1176 32 bool 33 select HAS_VBAR 34 35config CPU_V7 36 bool 37 select HAS_VBAR 38 select HAS_THUMB2 39 40config CPU_V7M 41 bool 42 select HAS_THUMB2 43 44config CPU_PXA 45 bool 46 47config CPU_SA1100 48 bool 49 50config SYS_CPU 51 default "arm720t" if CPU_ARM720T 52 default "arm920t" if CPU_ARM920T 53 default "arm926ejs" if CPU_ARM926EJS 54 default "arm946es" if CPU_ARM946ES 55 default "arm1136" if CPU_ARM1136 56 default "arm1176" if CPU_ARM1176 57 default "armv7" if CPU_V7 58 default "armv7m" if CPU_V7M 59 default "pxa" if CPU_PXA 60 default "sa1100" if CPU_SA1100 61 default "armv8" if ARM64 62 63config SEMIHOSTING 64 bool "support boot from semihosting" 65 help 66 In emulated environments, semihosting is a way for 67 the hosted environment to call out to the emulator to 68 retrieve files from the host machine. 69 70config SYS_L2CACHE_OFF 71 bool "L2cache off" 72 help 73 If SoC does not support L2CACHE or one do not want to enable 74 L2CACHE, choose this option. 75 76choice 77 prompt "Target select" 78 default TARGET_HIKEY 79 80config ARCH_AT91 81 bool "Atmel AT91" 82 83config TARGET_EDB93XX 84 bool "Support edb93xx" 85 select CPU_ARM920T 86 87config TARGET_VCMA9 88 bool "Support VCMA9" 89 select CPU_ARM920T 90 91config TARGET_SMDK2410 92 bool "Support smdk2410" 93 select CPU_ARM920T 94 95config TARGET_ASPENITE 96 bool "Support aspenite" 97 select CPU_ARM926EJS 98 99config TARGET_GPLUGD 100 bool "Support gplugd" 101 select CPU_ARM926EJS 102 103config ARCH_DAVINCI 104 bool "TI DaVinci" 105 select CPU_ARM926EJS 106 help 107 Support for TI's DaVinci platform. 108 109config KIRKWOOD 110 bool "Marvell Kirkwood" 111 select CPU_ARM926EJS 112 113config ARCH_MVEBU 114 bool "Marvell MVEBU family (Armada XP/38x)" 115 select CPU_V7 116 select SUPPORT_SPL 117 select OF_CONTROL 118 select OF_SEPARATE 119 select DM 120 select DM_SERIAL 121 122config TARGET_DEVKIT3250 123 bool "Support devkit3250" 124 select CPU_ARM926EJS 125 select SUPPORT_SPL 126 127config TARGET_WORK_92105 128 bool "Support work_92105" 129 select CPU_ARM926EJS 130 select SUPPORT_SPL 131 132config TARGET_MX25PDK 133 bool "Support mx25pdk" 134 select CPU_ARM926EJS 135 136config TARGET_ZMX25 137 bool "Support zmx25" 138 select CPU_ARM926EJS 139 140config TARGET_APF27 141 bool "Support apf27" 142 select CPU_ARM926EJS 143 select SUPPORT_SPL 144 145config TARGET_APX4DEVKIT 146 bool "Support apx4devkit" 147 select CPU_ARM926EJS 148 select SUPPORT_SPL 149 150config TARGET_XFI3 151 bool "Support xfi3" 152 select CPU_ARM926EJS 153 select SUPPORT_SPL 154 155config TARGET_M28EVK 156 bool "Support m28evk" 157 select CPU_ARM926EJS 158 select SUPPORT_SPL 159 160config TARGET_MX23EVK 161 bool "Support mx23evk" 162 select CPU_ARM926EJS 163 select SUPPORT_SPL 164 165config TARGET_MX28EVK 166 bool "Support mx28evk" 167 select CPU_ARM926EJS 168 select SUPPORT_SPL 169 170config TARGET_MX23_OLINUXINO 171 bool "Support mx23_olinuxino" 172 select CPU_ARM926EJS 173 select SUPPORT_SPL 174 175config TARGET_BG0900 176 bool "Support bg0900" 177 select CPU_ARM926EJS 178 select SUPPORT_SPL 179 180config TARGET_SANSA_FUZE_PLUS 181 bool "Support sansa_fuze_plus" 182 select CPU_ARM926EJS 183 select SUPPORT_SPL 184 185config TARGET_SC_SPS_1 186 bool "Support sc_sps_1" 187 select CPU_ARM926EJS 188 select SUPPORT_SPL 189 190config ORION5X 191 bool "Marvell Orion" 192 select CPU_ARM926EJS 193 194config TARGET_SPEAR300 195 bool "Support spear300" 196 select CPU_ARM926EJS 197 198config TARGET_SPEAR310 199 bool "Support spear310" 200 select CPU_ARM926EJS 201 202config TARGET_SPEAR320 203 bool "Support spear320" 204 select CPU_ARM926EJS 205 206config TARGET_SPEAR600 207 bool "Support spear600" 208 select CPU_ARM926EJS 209 210config TARGET_STV0991 211 bool "Support stv0991" 212 select CPU_V7 213 select DM 214 select DM_SERIAL 215 select DM_SPI 216 select DM_SPI_FLASH 217 select SPI_FLASH 218 219config TARGET_X600 220 bool "Support x600" 221 select CPU_ARM926EJS 222 select SUPPORT_SPL 223 224config TARGET_IMX31_PHYCORE 225 bool "Support imx31_phycore" 226 select CPU_ARM1136 227 228config TARGET_MX31ADS 229 bool "Support mx31ads" 230 select CPU_ARM1136 231 232config TARGET_MX31PDK 233 bool "Support mx31pdk" 234 select CPU_ARM1136 235 select SUPPORT_SPL 236 237config TARGET_WOODBURN 238 bool "Support woodburn" 239 select CPU_ARM1136 240 241config TARGET_WOODBURN_SD 242 bool "Support woodburn_sd" 243 select CPU_ARM1136 244 select SUPPORT_SPL 245 246config TARGET_FLEA3 247 bool "Support flea3" 248 select CPU_ARM1136 249 250config TARGET_MX35PDK 251 bool "Support mx35pdk" 252 select CPU_ARM1136 253 254config ARCH_BCM283X 255 bool "Broadcom BCM283X family" 256 select DM 257 select DM_SERIAL 258 select DM_GPIO 259 260config TARGET_VEXPRESS_CA15_TC2 261 bool "Support vexpress_ca15_tc2" 262 select CPU_V7 263 select CPU_V7_HAS_NONSEC 264 select CPU_V7_HAS_VIRT 265 266config TARGET_VEXPRESS_CA5X2 267 bool "Support vexpress_ca5x2" 268 select CPU_V7 269 270config TARGET_VEXPRESS_CA9X4 271 bool "Support vexpress_ca9x4" 272 select CPU_V7 273 274config TARGET_KWB 275 bool "Support kwb" 276 select CPU_V7 277 select SUPPORT_SPL 278 279config TARGET_TSERIES 280 bool "Support tseries" 281 select CPU_V7 282 select SUPPORT_SPL 283 284config TARGET_CM_T335 285 bool "Support cm_t335" 286 select CPU_V7 287 select SUPPORT_SPL 288 select DM 289 select DM_SERIAL 290 select DM_GPIO 291 292config TARGET_PEPPER 293 bool "Support pepper" 294 select CPU_V7 295 select SUPPORT_SPL 296 select DM 297 select DM_SERIAL 298 select DM_GPIO 299 300config TARGET_AM335X_IGEP0033 301 bool "Support am335x_igep0033" 302 select CPU_V7 303 select SUPPORT_SPL 304 select DM 305 select DM_SERIAL 306 select DM_GPIO 307 308config TARGET_PCM051 309 bool "Support pcm051" 310 select CPU_V7 311 select SUPPORT_SPL 312 select DM 313 select DM_SERIAL 314 select DM_GPIO 315 316config TARGET_DRACO 317 bool "Support draco" 318 select CPU_V7 319 select SUPPORT_SPL 320 321config TARGET_THUBAN 322 bool "Support thuban" 323 select CPU_V7 324 select SUPPORT_SPL 325 326config TARGET_RASTABAN 327 bool "Support rastaban" 328 select CPU_V7 329 select SUPPORT_SPL 330 331config TARGET_PXM2 332 bool "Support pxm2" 333 select CPU_V7 334 select SUPPORT_SPL 335 336config TARGET_RUT 337 bool "Support rut" 338 select CPU_V7 339 select SUPPORT_SPL 340 341config TARGET_PENGWYN 342 bool "Support pengwyn" 343 select CPU_V7 344 select SUPPORT_SPL 345 select DM 346 select DM_SERIAL 347 select DM_GPIO 348 349config TARGET_AM335X_BALTOS 350 bool "Support am335x_baltos" 351 select CPU_V7 352 select SUPPORT_SPL 353 select DM 354 select DM_SERIAL 355 select DM_GPIO 356 357config TARGET_AM335X_EVM 358 bool "Support am335x_evm" 359 select CPU_V7 360 select SUPPORT_SPL 361 select DM 362 select DM_SERIAL 363 select DM_GPIO 364 365config TARGET_AM335X_SL50 366 bool "Support am335x_sl50" 367 select CPU_V7 368 select SUPPORT_SPL 369 select DM 370 select DM_SERIAL 371 372config TARGET_AM43XX_EVM 373 bool "Support am43xx_evm" 374 select CPU_V7 375 select SUPPORT_SPL 376 377config TARGET_BAV335X 378 bool "Support bav335x" 379 select CPU_V7 380 select SUPPORT_SPL 381 select DM 382 select DM_SERIAL 383 help 384 The BAV335x OEM Network Processor integrates all the functions of an 385 embedded network computer in a small, easy to use SODIMM module which 386 incorporates the popular Texas Instruments Sitara 32bit ARM Coretex-A8 387 processor, with fast DDR3 512MB SDRAM, 4GB of embedded MMC and a Gigabit 388 ethernet with simple connection to external connectors. 389 390 For more information, visit: http://birdland.com/oem 391 392config TARGET_TI814X_EVM 393 bool "Support ti814x_evm" 394 select CPU_V7 395 select SUPPORT_SPL 396 397config TARGET_TI816X_EVM 398 bool "Support ti816x_evm" 399 select CPU_V7 400 select SUPPORT_SPL 401 402config TARGET_BCM28155_AP 403 bool "Support bcm28155_ap" 404 select CPU_V7 405 406config TARGET_BCMCYGNUS 407 bool "Support bcmcygnus" 408 select CPU_V7 409 410config TARGET_BCMNSP 411 bool "Support bcmnsp" 412 select CPU_V7 413 414config ARCH_EXYNOS 415 bool "Samsung EXYNOS" 416 select CPU_V7 417 select DM 418 select DM_SPI_FLASH 419 select DM_SERIAL 420 select DM_SPI 421 select DM_GPIO 422 423config ARCH_S5PC1XX 424 bool "Samsung S5PC1XX" 425 select CPU_V7 426 select DM 427 select DM_SERIAL 428 select DM_GPIO 429 430config ARCH_HIGHBANK 431 bool "Calxeda Highbank" 432 select CPU_V7 433 434config ARCH_INTEGRATOR 435 bool "ARM Ltd. Integrator family" 436 select DM 437 select DM_SERIAL 438 439config ARCH_KEYSTONE 440 bool "TI Keystone" 441 select CPU_V7 442 select SUPPORT_SPL 443 444config ARCH_MX7 445 bool "Freescale MX7" 446 select CPU_V7 447 448config ARCH_MX6 449 bool "Freescale MX6" 450 select CPU_V7 451 452config ARCH_MX5 453 bool "Freescale MX5" 454 select CPU_V7 455 456config TARGET_M53EVK 457 bool "Support m53evk" 458 select CPU_V7 459 select SUPPORT_SPL 460 461config TARGET_MX51EVK 462 bool "Support mx51evk" 463 select CPU_V7 464 465config TARGET_MX53ARD 466 bool "Support mx53ard" 467 select CPU_V7 468 469config TARGET_MX53EVK 470 bool "Support mx53evk" 471 select CPU_V7 472 473config TARGET_MX53LOCO 474 bool "Support mx53loco" 475 select CPU_V7 476 477config TARGET_MX53SMD 478 bool "Support mx53smd" 479 select CPU_V7 480 481config OMAP34XX 482 bool "OMAP34XX SoC" 483 select CPU_V7 484 485config OMAP44XX 486 bool "OMAP44XX SoC" 487 select CPU_V7 488 select SUPPORT_SPL 489 490config OMAP54XX 491 bool "OMAP54XX SoC" 492 select CPU_V7 493 select SUPPORT_SPL 494 495config RMOBILE 496 bool "Renesas ARM SoCs" 497 select CPU_V7 498 499config ARCH_SOCFPGA 500 bool "Altera SOCFPGA family" 501 select CPU_V7 502 select SUPPORT_SPL 503 select OF_CONTROL 504 select SPL_OF_CONTROL 505 select DM 506 select DM_SPI_FLASH 507 select DM_SPI 508 509config TARGET_CM_T43 510 bool "Support cm_t43" 511 select CPU_V7 512 select SUPPORT_SPL 513 514config ARCH_SUNXI 515 bool "Support sunxi (Allwinner) SoCs" 516 select CMD_USB 517 select DM 518 select DM_GPIO 519 select DM_ETH 520 select DM_SERIAL 521 select DM_USB 522 select OF_CONTROL 523 select OF_SEPARATE 524 select SPL_STACK_R if !MACH_SUN9I 525 select SPL_SYS_MALLOC_SIMPLE if !MACH_SUN9I 526 select USB 527 select USB_STORAGE 528 select USB_KEYBOARD 529 530config TARGET_TS4800 531 bool "Support TS4800" 532 select CPU_V7 533 534config TARGET_VF610TWR 535 bool "Support vf610twr" 536 select CPU_V7 537 538config TARGET_COLIBRI_VF 539 bool "Support Colibri VF50/61" 540 select CPU_V7 541 542config TARGET_PCM052 543 bool "Support pcm-052" 544 select CPU_V7 545 546config ARCH_ZYNQ 547 bool "Xilinx Zynq Platform" 548 select CPU_V7 549 select SUPPORT_SPL 550 select OF_CONTROL 551 select SPL_OF_CONTROL 552 select DM 553 select SPL_DM 554 select DM_SPI 555 select DM_SERIAL 556 select DM_SPI_FLASH 557 select SPL_SEPARATE_BSS 558 559config ARCH_ZYNQMP 560 bool "Support Xilinx ZynqMP Platform" 561 select ARM64 562 select DM 563 select OF_CONTROL 564 select DM_SERIAL 565 566config TEGRA 567 bool "NVIDIA Tegra" 568 569config TARGET_VEXPRESS64_AEMV8A 570 bool "Support vexpress_aemv8a" 571 select ARM64 572 573config TARGET_VEXPRESS64_BASE_FVP 574 bool "Support Versatile Express ARMv8a FVP BASE model" 575 select ARM64 576 select SEMIHOSTING 577 578config TARGET_VEXPRESS64_BASE_FVP_DRAM 579 bool "Support Versatile Express ARMv8a FVP BASE model booting from DRAM" 580 select ARM64 581 help 582 This target is derived from TARGET_VEXPRESS64_BASE_FVP and over-rides 583 the default config to allow the user to load the images directly into 584 DRAM using model parameters rather than by using semi-hosting to load 585 the files from the host filesystem. 586 587config TARGET_VEXPRESS64_JUNO 588 bool "Support Versatile Express Juno Development Platform" 589 select ARM64 590 591config TARGET_LS2085A_EMU 592 bool "Support ls2085a_emu" 593 select ARM64 594 select ARMV8_MULTIENTRY 595 596config TARGET_LS2085A_SIMU 597 bool "Support ls2085a_simu" 598 select ARM64 599 select ARMV8_MULTIENTRY 600 601config TARGET_LS2085AQDS 602 bool "Support ls2085aqds" 603 select ARM64 604 select ARMV8_MULTIENTRY 605 select SUPPORT_SPL 606 help 607 Support for Freescale LS2085AQDS platform 608 The LS2085A Development System (QDS) is a high-performance 609 development platform that supports the QorIQ LS2085A 610 Layerscape Architecture processor. 611 612config TARGET_LS2085ARDB 613 bool "Support ls2085ardb" 614 select ARM64 615 select ARMV8_MULTIENTRY 616 select SUPPORT_SPL 617 help 618 Support for Freescale LS2085ARDB platform. 619 The LS2085A Reference design board (RDB) is a high-performance 620 development platform that supports the QorIQ LS2085A 621 Layerscape Architecture processor. 622 623config TARGET_HIKEY 624 bool "Support HiKey 96boards Consumer Edition Platform" 625 select ARM64 626 select DM 627 select DM_GPIO 628 select DM_SERIAL 629 help 630 Support for HiKey 96boards platform. It features a HI6220 631 SoC, with 8xA53 CPU, mali450 gpu, and 1GB RAM. 632 633config TARGET_LS1021AQDS 634 bool "Support ls1021aqds" 635 select CPU_V7 636 select SUPPORT_SPL 637config TARGET_LS1021ATWR 638 bool "Support ls1021atwr" 639 select CPU_V7 640 select SUPPORT_SPL 641 642config TARGET_LS1043ARDB 643 bool "Support ls1043ardb" 644 select ARM64 645 select ARMV8_MULTIENTRY 646 select SUPPORT_SPL 647 help 648 Support for Freescale LS1043ARDB platform. 649 650config TARGET_H2200 651 bool "Support h2200" 652 select CPU_PXA 653 654config TARGET_COLIBRI_PXA270 655 bool "Support colibri_pxa270" 656 select CPU_PXA 657 658config ARCH_UNIPHIER 659 bool "Socionext UniPhier SoCs" 660 select CPU_V7 661 select SUPPORT_SPL 662 select SPL 663 select OF_CONTROL 664 select SPL_OF_CONTROL 665 select DM 666 select SPL_DM 667 select DM_SERIAL 668 select DM_I2C 669 help 670 Support for UniPhier SoC family developed by Socionext Inc. 671 (formerly, System LSI Business Division of Panasonic Corporation) 672 673config TARGET_STM32F429_DISCOVERY 674 bool "Support STM32F429 Discovery" 675 select CPU_V7M 676 677config ARCH_ROCKCHIP 678 bool "Support Rockchip SoCs" 679 select SUPPORT_SPL 680 select SPL 681 select OF_CONTROL 682 select CPU_V7 683 select DM 684 685endchoice 686 687source "arch/arm/mach-at91/Kconfig" 688 689source "arch/arm/mach-bcm283x/Kconfig" 690 691source "arch/arm/mach-davinci/Kconfig" 692 693source "arch/arm/mach-exynos/Kconfig" 694 695source "arch/arm/mach-highbank/Kconfig" 696 697source "arch/arm/mach-integrator/Kconfig" 698 699source "arch/arm/mach-keystone/Kconfig" 700 701source "arch/arm/mach-kirkwood/Kconfig" 702 703source "arch/arm/mach-mvebu/Kconfig" 704 705source "arch/arm/cpu/armv7/mx7/Kconfig" 706 707source "arch/arm/cpu/armv7/mx6/Kconfig" 708 709source "arch/arm/cpu/armv7/mx5/Kconfig" 710 711source "arch/arm/cpu/armv7/omap3/Kconfig" 712 713source "arch/arm/cpu/armv7/omap4/Kconfig" 714 715source "arch/arm/cpu/armv7/omap5/Kconfig" 716 717source "arch/arm/mach-orion5x/Kconfig" 718 719source "arch/arm/cpu/armv7/rmobile/Kconfig" 720 721source "arch/arm/mach-rockchip/Kconfig" 722 723source "arch/arm/cpu/armv7/s5pc1xx/Kconfig" 724 725source "arch/arm/mach-socfpga/Kconfig" 726 727source "arch/arm/mach-tegra/Kconfig" 728 729source "arch/arm/mach-uniphier/Kconfig" 730 731source "arch/arm/mach-zynq/Kconfig" 732 733source "arch/arm/cpu/armv7/Kconfig" 734 735source "arch/arm/cpu/armv8/zynqmp/Kconfig" 736 737source "arch/arm/cpu/armv8/Kconfig" 738 739source "arch/arm/imx-common/Kconfig" 740 741source "board/BuR/kwb/Kconfig" 742source "board/BuR/tseries/Kconfig" 743source "board/CarMediaLab/flea3/Kconfig" 744source "board/Marvell/aspenite/Kconfig" 745source "board/Marvell/db-88f6820-gp/Kconfig" 746source "board/Marvell/db-mv784mp-gp/Kconfig" 747source "board/Marvell/gplugd/Kconfig" 748source "board/armadeus/apf27/Kconfig" 749source "board/armltd/vexpress/Kconfig" 750source "board/armltd/vexpress64/Kconfig" 751source "board/bluegiga/apx4devkit/Kconfig" 752source "board/broadcom/bcm28155_ap/Kconfig" 753source "board/broadcom/bcmcygnus/Kconfig" 754source "board/broadcom/bcmnsp/Kconfig" 755source "board/cirrus/edb93xx/Kconfig" 756source "board/compulab/cm_t335/Kconfig" 757source "board/compulab/cm_t43/Kconfig" 758source "board/creative/xfi3/Kconfig" 759source "board/denx/m28evk/Kconfig" 760source "board/denx/m53evk/Kconfig" 761source "board/freescale/ls2085a/Kconfig" 762source "board/freescale/ls2085aqds/Kconfig" 763source "board/freescale/ls2085ardb/Kconfig" 764source "board/freescale/ls1021aqds/Kconfig" 765source "board/freescale/ls1021atwr/Kconfig" 766source "board/freescale/ls1043ardb/Kconfig" 767source "board/freescale/mx23evk/Kconfig" 768source "board/freescale/mx25pdk/Kconfig" 769source "board/freescale/mx28evk/Kconfig" 770source "board/freescale/mx31ads/Kconfig" 771source "board/freescale/mx31pdk/Kconfig" 772source "board/freescale/mx35pdk/Kconfig" 773source "board/freescale/mx51evk/Kconfig" 774source "board/freescale/mx53ard/Kconfig" 775source "board/freescale/mx53evk/Kconfig" 776source "board/freescale/mx53loco/Kconfig" 777source "board/freescale/mx53smd/Kconfig" 778source "board/freescale/vf610twr/Kconfig" 779source "board/gumstix/pepper/Kconfig" 780source "board/h2200/Kconfig" 781source "board/hisilicon/hikey/Kconfig" 782source "board/imx31_phycore/Kconfig" 783source "board/isee/igep0033/Kconfig" 784source "board/maxbcm/Kconfig" 785source "board/mpl/vcma9/Kconfig" 786source "board/olimex/mx23_olinuxino/Kconfig" 787source "board/phytec/pcm051/Kconfig" 788source "board/phytec/pcm052/Kconfig" 789source "board/ppcag/bg0900/Kconfig" 790source "board/samsung/smdk2410/Kconfig" 791source "board/sandisk/sansa_fuze_plus/Kconfig" 792source "board/schulercontrol/sc_sps_1/Kconfig" 793source "board/siemens/draco/Kconfig" 794source "board/siemens/pxm2/Kconfig" 795source "board/siemens/rut/Kconfig" 796source "board/silica/pengwyn/Kconfig" 797source "board/spear/spear300/Kconfig" 798source "board/spear/spear310/Kconfig" 799source "board/spear/spear320/Kconfig" 800source "board/spear/spear600/Kconfig" 801source "board/spear/x600/Kconfig" 802source "board/st/stm32f429-discovery/Kconfig" 803source "board/st/stv0991/Kconfig" 804source "board/sunxi/Kconfig" 805source "board/syteco/zmx25/Kconfig" 806source "board/tcl/sl50/Kconfig" 807source "board/ti/am335x/Kconfig" 808source "board/ti/am43xx/Kconfig" 809source "board/birdland/bav335x/Kconfig" 810source "board/ti/ti814x/Kconfig" 811source "board/ti/ti816x/Kconfig" 812source "board/timll/devkit3250/Kconfig" 813source "board/toradex/colibri_pxa270/Kconfig" 814source "board/toradex/colibri_vf/Kconfig" 815source "board/technologic/ts4800/Kconfig" 816source "board/vscom/baltos/Kconfig" 817source "board/woodburn/Kconfig" 818source "board/work-microwave/work_92105/Kconfig" 819 820source "arch/arm/Kconfig.debug" 821 822endmenu 823