u-boot/doc/README.sbc8548
Paul Gortmaker dd9ca98f26 sbc8548: reclaim wasted sector in boot flash
By nature of being based off the MPC8548CDS board, this
board inherited an ENV_SIZE setting of 256k.  But since
it has a smaller flash device (8MB soldered on), it has
a native sector size of 128k, and hence the ENV_SIZE was
causing 2 sectors to be used for the environment.

By removing the unused sector, we can push TEXT_BASE up
closer to the end of address space and reclaim that
sector for any other application.  This also fixes the
mismatch between TEXT_BASE and MONITOR_LEN reported by
Kumar earlier.

Since this board also supports the ability to boot off
the 64MB SODIMM flash, this change is forward looking
with that in mind; i.e. the settings for MONITOR_LEN
and ENV_SIZE will work when the 512k sectors of the
SODIMM flash are used for alternate boot in the future.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-09-30 08:29:47 -05:00

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Intro:
======
The SBC8548 is a stand alone single board computer with a 1GHz
MPC8548 CPU, 8MB boot flash, 64MB user flash and, 256MB DDR2 400MHz
memory. It also has 128MB SDRAM 100MHz LBC memory, with both a PCI-e,
and a PCI-X slot, dual mini-DB9 for UART, and dual RJ-45 for eTSEC
ethernet connections.
U-boot Configuration:
=====================
The following possible u-boot configuration targets are available:
1) sbc8548_config
2) sbc8548_PCI_33_config
3) sbc8548_PCI_66_config
4) sbc8548_PCI_33_PCIE_config
5) sbc8548_PCI_66_PCIE_config
Generally speaking, most people should choose to use #5. Details
of each choice are listed below.
Choice #1 does not enable CONFIG_PCI, and assumes that the PCI slot
will be left empty (M66EN high), and so the board will operate with
a base clock of 66MHz. Note that you need both PCI enabled in u-boot
and linux in order to have functional PCI under linux.
The second enables PCI support and builds for a 33MHz clock rate. Note
that if a 33MHz 32bit card is inserted in the slot, then the whole board
will clock down to a 33MHz base clock instead of the default 66MHz. This
will change the baud clocks and mess up your serial console output if you
were previously running at 66MHz. If you want to use a 33MHz PCI card,
then you should build a U-Boot with a _PCI_33_ config and store this
to flash prior to powering down the board and inserting the 33MHz PCI
card. [The above discussion assumes that the SW2[1-4] has not been changed
to reflect a different CCB:SYSCLK ratio]
The third option builds PCI support in, and leaves the clocking at the
default 66MHz. Options four and five are just repeats of option two
and three, but with PCI-e support enabled as well.
PCI output listing with an intel e1000 PCI-x and a Syskonnect SK-9Exx
is shown below for sbc8548_PCI_66_PCIE_config. (Note that PCI-e with
a 33MHz PCI configuration is currently untested.)
=> pci 0
Scanning PCI devices on bus 0
BusDevFun VendorId DeviceId Device Class Sub-Class
_____________________________________________________________
00.00.00 0x1057 0x0012 Processor 0x20
00.01.00 0x8086 0x1026 Network controller 0x00
=> pci 1
Scanning PCI devices on bus 1
BusDevFun VendorId DeviceId Device Class Sub-Class
_____________________________________________________________
01.00.00 0x1957 0x0012 Processor 0x20
=> pci 2
Scanning PCI devices on bus 2
BusDevFun VendorId DeviceId Device Class Sub-Class
_____________________________________________________________
02.00.00 0x1148 0x9e00 Network controller 0x00
=>
Updating U-boot with U-boot:
============================
Note that versions of u-boot up to and including 2009.08 had u-boot stored
at 0xfff8_0000 -> 0xffff_ffff (512k). Currently it is being stored from
0xfffa_0000 -> 0xffff_ffff (384k). If you use an old macro/script to
update u-boot with u-boot and it uses the old address, you will render
your board inoperable, and you will require JTAG recovery.
The following steps list how to update with the current address:
tftp u-boot.bin
md 200000 10
protect off all
erase fffa0000 ffffffff
cp.b 200000 fffa0000 60000
md fffa0000 10
protect on all
The "md" steps in the above are just a precautionary step that allow
you to confirm the u-boot version that was downloaded, and then confirm
that it was copied to flash.
Hardware Reference:
===================
The following contains some summary information on hardware settings
that are relevant to u-boot, based on the board manual. For the
most up to date and complete details of the board, please request the
reference manual ERG-00327-001.pdf from www.windriver.com
Boot flash:
intel V28F640Jx, 8192x8 (one device) at 0xff80_0000
Sodimm flash:
intel V28F128Jx, 16384x8 (4 devices) at 0xfb80_0000
Jumpers:
Jumper Name ON OFF
----------------------------------------------------------------
JP12 CS0/CS6 swap see note[*] see note[*]
JP13 SODIMM flash write OK writes disabled
write prot.
JP14 HRESET/TRST joined isolated
JP15 PWR ON when AC pwr use S1 for on/off
JP16 Demo LEDs lit not lit
JP19 PCI mode PCI PCI-X
[*]JP12, when jumpered parallel to the SODIMM, puts the boot flash
onto /CS0 and the SODIMM flash on /CS6 (default). When JP12
is jumpered parallel to the LBC-SDRAM, then /CS0 is for the
SODIMM flash and /CS6 is for the boot flash. Note that in this
alternate setting, you also need to switch SW2.8 to ON. Currently
u-boot doesn't support booting off the SODIMM in this alternate
setting without manually altering BR0/OR0 and BR6/OR6 in the
board config file appropriately.
Switches:
The defaults are marked with a *
Name Desc. ON OFF
------------------------------------------------------------------
S1 Pwr toggle n/a n/a
SW2.1 CFG_SYS_PLL0 1 0*
SW2.2 CFG_SYS_PLL1 1* 0
SW2.3 CFG_SYS_PLL2 1* 0
SW2.4 CFG_SYS_PLL3 1 0*
SW2.5 CFG_CORE_PLL0 1* 0
SW2.6 CFG_CORE_PLL1 1 0*
SW2.7 CFG_CORE_PLL2 1* 0
SW2.8 CFG_ROM_LOC1 1 0*
SW3.1 CFG_HOST_AGT0 1* 0
SW3.2 CFG_HOST_AGT1 1* 0
SW3.3 CFG_HOST_AGT2 1* 0
SW3.4 CFG_IO_PORTS0 1* 0
SW3.5 CFG_IO_PORTS0 1 0*
SW3.6 CFG_IO_PORTS0 1 0*
SerDes CLK(MHz) SW5.1 SW5.2
----------------------------------------------
25 0 0
100* 1 0
125 0 1
200 1 1
SerDes CLK spread SW5.3 SW5.4
----------------------------------------------
+/- 0.25% 0 0
-0.50% 1 0
-0.75% 0 1
No Spread* 1 1
SW4 settings are readable from the EPLD and are currently not used for
any hardware settings (i.e. user configuration switches).
LEDs:
Name Desc. ON OFF
------------------------------------------------------------------
D13 PCI/PCI-X PCI-X PCI
D14 3.3V PWR 3.3V no power
D15 SYSCLK 66MHz 33MHz
Default Memory Map:
start end CS<n> width Desc.
----------------------------------------------------------------------
0000_0000 0fff_ffff MCS0,1 64 DDR2 (256MB)
f000_0000 f7ff_ffff CS3,4 32 LB SDRAM (128MB)
f800_0000 f8b0_1fff CS5 - EPLD
fb80_0000 ff7f_ffff CS6 32 SODIMM flash (64MB)
ff80_0000 ffff_ffff CS0 8 Boot flash (8MB)
The EPLD on CS5 demuxes the following devices at the following offsets:
offset size width device
--------------------------------------------------------
0 1fff 8 7 segment display LED
10_0000 1fff 4 user switches
30_0000 1fff 4 HW Rev. register
b0_0000 1fff 8 8kB EEPROM