GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/board/armltd/integrator/README

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+
+		U-Boot for ARM Integrator Development Platforms
+
+			Peter Pearse, ARM Ltd.
+			peter.pearse@arm.com
+			     www.arm.com
+
+Manuals available from :-
+http://www.arm.com/products/DevTools/Hardware_Platforms.html
+
+Overview :
+--------
+There are two Integrator variants - Integrator/AP and Integrator/CP.
+Each may be fitted with a variety of core modules (CMs).
+Each CM consists of a ARM processor core and associated hardware e.g
+	FPGA implementing various controllers and/or register
+	SSRAM
+	SDRAM
+	RAM controllers
+	clock generators etc.
+CMs may be fitted with varying amounts of SDRAM using a DIMM socket.
+
+Boot Methods :
+------------
+Integrator platforms can be configured to use U-Boot in at least three ways :-
+a) Run ARM boot monitor, manually run U-Boot image from flash
+b) Run ARM boot monitor, automatically run U-Boot image from flash
+c) Run U-Boot image direct from flash.
+
+In cases a) and b) the ARM boot monitor will have configured the CM and mapped
+writeable memory to 0x00000000 in the Integrator address space.
+U-Boot has to carry out minimal configration before standard code is run.
+
+In case c) it may be necessary for U-Boot to perform CM dependent initialization.
+
+Configuring U-Boot :
+------------------
+	The makefile contains targets for Integrator platforms of both types
+fitted with all current variants of CM.
+
+	There are also targets independent of CM. These may not be suitable for
+boot process c) above. They have been preserved for backward compatibility with
+existing build processes.
+
+Code Hierarchy Applied :
+----------------------
+Code specific to initialization of a particular ARM processor has been placed in
+cpu/arm<>/start.S so that it may be used by other boards.
+
+However, to avoid duplicating code through all processor files, a generic core
+for ARM Integrator CMs has been added
+
+	arch/arm/cpu/arm_intcm
+
+Otherwise. for example,  the standard CM reset via the CM control register would
+need placing in each CM processor file......
+
+Code specific to the initialization of the CM, rather than the cpu, and initialization
+of the Integrator board itself, has been placed in
+
+	board/integrator<>/platform.S
+	board/integrator<>/integrator<>.c
+
+Targets
+=======
+The U-Boot make targets map to the available core modules as below.
+
+Integrator/AP is no longer available from ARM.
+Core modules marked ** are also no longer available.
+
+ap720t_config		** CM720T
+ap920t_config		** CM920T
+ap926ejs_config	Integrator Core Module for ARM926EJ-STM
+ap946es_config		Integrator Core Module for ARM946E-STM
+cp920t_config		** CM920T
+cp926ejs_config	Integrator Core Module for ARM926EJ-STM
+cp946es_config		Integrator Core Module for ARM946E-STM
+cp1136_config		Integrator Core Module ARM1136JF-S  TM
+
+The final groups of targets are for core modules where no explicit cpu
+code has yet been added to U-Boot i.e. they all use the same U-Boot binary
+using the generic "arm_intcm" core:
+
+ap966_config			Integrator Core Module for ARM966E-S TM
+ap922_config			Integrator Core Module for ARM922T TM with ETM
+ap922_XA10_config		Integrator Core Module for ARM922T using Altera Excalibur
+ap7_config			** CM7TDMI
+integratorap_config
+ap_config
+
+
+cp966_config			Integrator Core Module for ARM966E-S TM
+cp922_config			Integrator Core Module for ARM922T TM with ETM
+cp922_XA10_config		Integrator Core Module for ARM922T using Altera Excalibur
+cp1026_config			Integrator Core Module ARM1026EJ-S TM
+integratorcp_config
+cp_config
+
+The Makefile targets call board/integrator<>/split_by_variant.sh
+to configure various defines in include/configs/integrator<>.h
+to indicate the core module & core configuration and ensure that
+board/integrator<>/u-boot.lds loads the cpu object first in the U-Boot image.
+
+*********************************
+Because of this mechanism
+> make clean
+must be run before each change in configuration
+*********************************