Add PPC4xx-HCU4 and HCU5 boards: READMEs

Signed-off-by: Niklaus Giger <niklaus.giger@netstal.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/board/netstal/hcu5/README.txt b/board/netstal/hcu5/README.txt
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+HCU5 configuration details and startup sequence
+
+(C) Copyright 2007 Netstal Maschinen AG
+    Niklaus Giger (Niklaus.Giger@netstal.com)
+
+TODO:
+-----
+- Fix error: Waiting for PHY auto negotiation to complete..... TIMEOUT !
+     - Does not occur if both EMAC are connected
+- Fix RTS/CTS problem (HW?)
+  CONFIG_SERIAL_MULTI/CONFIG_SERIAL_SOFTWARE_FIFO hangs after
+  Switching to interrupt driven serial input mode
+- Make vxWorks start from u-boot. Possible reasons
+    - Does vxWorks need an entry for the Machine Check interrupt like this
+      tlbentry( 0x40000000, SZ_256M, 0, 1, AC_R|AC_W|AC_X|SA_G|SA_I ) ?
+
+Caveats:
+--------
+Errata CHIP_8: Incorrect Write to DDR SDRAM. (was not applied to sequoia.c)
+see hcu5.c.
+
+
+Memory Bank 0 -- Flash chip
+---------------------------
+
+0xfff00000 - 0xffffffff
+
+The flash chip is really only 512Kbytes, but the high address bit of
+the 1Meg region is ignored, so the flash is replicated through the
+region. Thus, this is consistent with a flash base address 0xfff80000.
+
+The placement at the end is to be consistent with reset behavior,
+where the processor itself initially uses this bus to load the branch
+vector and start running.
+
+On-Chip Memory
+--------------
+
+0xe0010000- 0xe0013fff   CFG_OCM_BASE
+The 440EPx includes a 16K on-chip memory that can be placed however
+software chooses.
+
+Internal Peripherals
+--------------------
+
+0xef600300 - 0xef6008ff
+
+These are scattered various peripherals internal to the PPC440EPX
+chip.
+
+Chip-Select 2: Flash Memory
+---------------------------
+
+Not used
+
+Chip-Select 3: CAN Interface
+----------------------------
+0xc800000: 2 Intel 82527 CAN-Controller
+
+
+Chip-Select 4: IMC-bus standard
+-------------------------------
+
+0xcc00000: Netstal specific IO-Bus
+
+
+Chip-Select 5: IMC-bus fast (inactive)
+--------------------------------------
+
+0xce00000: Netstal specific IO-Bus (fast, but not yet used)
+
+
+Memory Bank 1 -- DDR2
+-------------------------------------
+
+0x00000000 - 0xfffffff   # Default 256 MB
+
+PCI ??
+
+USB ??
+Only USB_STORAGE is enabled to load vxWorks
+from a memory stick.
+
+System-LEDs ??? (Analog zu HCU4 ???)
+
+Startup sequence
+----------------
+
+(cpu/ppc4xx/resetvec.S)
+depending on configs option
+call _start_440 _start_pci oder _start
+
+(cpu/ppc4xx/start.S)
+
+_start_440:
+	initialize register like
+	CCR0
+	debug
+	setup interrupt vectors
+	configure cache regions
+	clear and setup TLB
+	enable internal RAM
+	jump start_ram
+	which in turn will jump to start
+_start:
+	Clear and set up some registers.
+	Debug setup
+	Setup the internal SRAM
+	Setup the stack in internal SRAM
+    setup stack pointer (r1)
+    setup GOT
+	call cpu_init_f	/* run low-level CPU init code	   (from Flash) */
+
+    call cpu_init_f
+    board_init_f: (lib_ppc\board.c)
+	init_sequence defines a list of function to be called
+	    board_early_init_f: (board/netstal/hcu5/hcu5.c)
+		We are using Bootstrap-Option A
+		if CPR0_ICFG_RLI_MASK == 0 then set some registers and reboot
+		Setup the GPIO pins
+		Setup the interrupt controller polarities, triggers, etc.
+		Ethernet, PCI, USB enable
+		setup BOOT FLASH (Chip timing)
+	    init_baudrate,
+	    serial_init
+	    checkcpu
+	    misc_init_f #ifdef
+	    init_func_i2c #ifdef
+	    post_init_f  #ifdef
+	    init_func_ram -> calls init_dram board/netstal/hcu5/sdram.c
+		(EYE function removed!!)
+	    test_dram call
+
+	 * Reserve memory at end of RAM for (top down in that order):
+	 *  - kernel log buffer
+	 *  - protected RAM
+	 *  - LCD framebuffer
+	 *  - monitor code
+	 *  - board info struct
+	Save local variables to board info struct
+	call relocate_code() does not return
+	relocate_code: (cpu/ppc4xx/start.S)
+-------------------------------------------------------
+From now on our copy is in RAM and we will run from there,
+	starting with board_init_r
+-------------------------------------------------------
+    board_init_r: (lib_ppc\board.c)
+	setup bd function pointers
+	trap_init
+	flash_init: (board/netstal/hcu5/flash.c)
+		/* setup for u-boot erase, update */
+	setup bd flash info
+	cpu_init_r: (cpu/ppc4xx/cpu_init.c)
+	    peripheral chip select in using defines like
+	    CFG_EBC_PB0A, CFG_EBC_PB0C from hcu5.h
+	mem_malloc_init
+	malloc_bin_reloc
+	spi_init (r or f)??? (CFG_ENV_IS_IN_EEPROM)
+	env_relocated
+	misc_init_r(bd): (board/netstal/hcu5.c)
+	    ethaddr mit serial number ergänzen
+    Then we will somehow go into the command loop
+
+Most of the HW specific code for the HCU5 may be found in
+include/configs/hcu5.h
+board/netstal/hcu5/*
+cpu/ppc4xx/*
+lib_ppc/*
+include/ppc440.h
+
+Drivers for serial etc are found under drivers/
+
+Don't ask question if you did not look at the README !!
+Most CFG_* and CONFIG_* switches are mentioned/explained there.