1 2 U-Boot for ARM Integrator Development Platforms 3 4 Peter Pearse, ARM Ltd. 5 peter.pearse@arm.com 6 www.arm.com 7 8Manuals available from :- 9http://www.arm.com/products/DevTools/Hardware_Platforms.html 10 11Overview : 12-------- 13There are two Integrator variants - Integrator/AP and Integrator/CP. 14Each may be fitted with a variety of core modules (CMs). 15Each CM consists of a ARM processor core and associated hardware e.g 16 FPGA implementing various controllers and/or register 17 SSRAM 18 SDRAM 19 RAM controllers 20 clock generators etc. 21CMs may be fitted with varying amounts of SDRAM using a DIMM socket. 22 23Boot Methods : 24------------ 25Integrator platforms can be configured to use U-Boot in at least three ways :- 26a) Run ARM boot monitor, manually run U-Boot image from flash 27b) Run ARM boot monitor, automatically run U-Boot image from flash 28c) Run U-Boot image direct from flash. 29 30In cases a) and b) the ARM boot monitor will have configured the CM and mapped 31writeable memory to 0x00000000 in the Integrator address space. 32U-Boot has to carry out minimal configration before standard code is run. 33 34In case c) it may be necessary for U-Boot to perform CM dependent initialization. 35 36Configuring U-Boot : 37------------------ 38 The makefile contains targets for Integrator platforms of both types 39fitted with all current variants of CM. If these targets are to be used with 40boot process c) above then CONFIG_INIT_CRITICAL may need to be defined to ensure 41that the CM is correctly configured. 42 43 There are also targets independent of CM. These may not be suitable for 44boot process c) above. They have been preserved for backward compatibility with 45existing build processes. 46 47Code Hierarchy Applied : 48---------------------- 49Code specific to initialization of a particular ARM processor has been placed in 50cpu/arm<>/start.S so that it may be used by other boards. 51 52However, to avoid duplicating code through all processor files, a generic core 53for ARM Integrator CMs has been added 54 55 cpu/arm_intcm 56 57Otherwise. for example, the standard CM reset via the CM control register would 58need placing in each CM processor file...... 59 60Code specific to the initialization of the CM, rather than the cpu, and initialization 61of the Integrator board itself, has been placed in 62 63 board/integrator<>/platform.S 64 board/integrator<>/integrator<>.c 65 66Targets 67======= 68The U-Boot make targets map to the available core modules as below. 69 70Integrator/AP is no longer available from ARM. 71Core modules marked ** are also no longer available. 72 73ap720t_config ** CM720T 74ap920t_config ** CM920T 75ap926ejs_config Integrator Core Module for ARM926EJ-STM 76ap946es_config Integrator Core Module for ARM946E-STM 77cp920t_config ** CM920T 78cp926ejs_config Integrator Core Module for ARM926EJ-STM 79cp946es_config Integrator Core Module for ARM946E-STM 80cp1136_config Integrator Core Module ARM1136JF-S TM 81 82The final groups of targets are for core modules where no explicit cpu 83code has yet been added to U-Boot i.e. they all use the same U-Boot binary 84using the generic "arm_intcm" core: 85 86ap966_config Integrator Core Module for ARM966E-S TM 87ap922_config Integrator Core Module for ARM922T TM with ETM 88ap922_XA10_config Integrator Core Module for ARM922T using Altera Excalibur 89ap7_config ** CM7TDMI 90integratorap_config 91ap_config 92 93 94cp966_config Integrator Core Module for ARM966E-S TM 95cp922_config Integrator Core Module for ARM922T TM with ETM 96cp922_XA10_config Integrator Core Module for ARM922T using Altera Excalibur 97cp1026_config Integrator Core Module ARM1026EJ-S TM 98integratorcp_config 99cp_config 100 101The Makefile targets call board/integrator<>/split_by_variant.sh 102to configure various defines in include/configs/integrator<>.h 103to indicate the core module & core configuration and ensure that 104board/integrator<>/u-boot.lds loads the cpu object first in the U-Boot image. 105 106********************************* 107Because of this mechanism 108> make clean 109must be run before each change in configuration 110********************************* 111