#
# Usage: <script> [device [rootspec]]
#
# Kernel load is attempted from TFS first and then TFTP.
# TFTP server is determined from the DHCP response.
#
# Possible [device [rootspec]] combinations are:
# nfs [server-ip [rootpath]]	(/dev/nfs)
# cf				(/dev/hda1)
# usb				(/dev/sda1)
# sd				(/dev/mmcblk0p1)
# rom [filename]		(/dev/rom0, ie. filesystem in internal flash)
# ram [filename]		(/dev/ram0, ie. mandatory initrd via TFS/TFTP)
#
# The script will always attempt to load an initrd from TFS even if the device
# is not "ram". If the device is "ram", loading via TFTP will also be
# attempted.
#
# See below for default values for kernel name, nfs server, nfs path,
# romfs filename and ramfs (initrd) filename; all can be overridden
# environmentally (command line takes precedence).

# Specify your default device here:
if $ARG1 sne \$ARG1 goto USER_SPEC
set ARG1 "ram"

# USER_SPEC:
# If your DHCP server is not a TFTP server and is not sufficiently
# configurable to nominate an external one, set the following environment
# variable to the IP address of your local TFTP server.
#set TFTPSRVR 192.168.1.100
if $KERNEL sne \$KERNEL goto KERNEL_SET
set KERNEL "zImage"
# KERNEL_SET:
if $INITRD sne \$INITRD goto INITRD_SET
set INITRD "initrd.gz"
# INITRD_SET:
if $ROMFS sne \$ROMFS goto ROMFS_SET
set ROMFS "romfs.img"
# ROMFS_SET:
if $NFSSERVER sne \$NFSSERVER goto NFSSRV_SET
set NFSSERVER "192.168.1.101"
# NFSSRV_SET:
if $NFSPATH sne \$NFSPATH goto NFSPATH_SET
set NFSPATH "/opt/hot-e_root"
# NFSPATH_SET:

set INITRDBASE 0x20800000

gosub PROBE_MEMORY
gosub GET_IPADD
gosub FIND_ROOTFS
gosub LOAD_INITRD
gosub BUILD_ATAGS
gosub LOAD_KERNEL

# Launch the kernel:
# r0 == 0
# r1 == machine ID (0 means "pick one")
# r2 == ATAGS pointer
call $APPRAMBASE 0 577 $ATAGS
exit

# ----------------------------------------------------------------------------

# PROBE_MEMORY:

# Calculate MEMSIZE and MEMBASE
set MEMBASE $APPRAMBASE
# -a = bitwise and
set -a MEMBASE 0xf0000000
# mt -S sets MEMSIZE
mt -S $MEMBASE 0x8000000
return

# ----------------------------------------------------------------------------

# GET_IPADD:

set IPADD ""
set DHCPCLASSID "$PLATFORM"

# Issue the DHCP DISCOVER
#
# Successful dhcp call sets BOOTSRVR, GIPADD, IPADD, NETMASK
# Unfortunately it doesn't make any NFS root path information available to us.
#
# The dhcp call also causes any DHCP-specified bootfile ($BOOTFILE) to be
# loaded into TFS and executed.  This script assumes that no bootfile option
# is present, or that TFTP/TFS loading will not succeed.  If it is/does, this
# script will end here.  Fortunately uMon can be tricked into failing
# downloads of PXE boot loaders and the like by using a comma in the pathname
# (details elsewhere).
#
dhcp

# Wait for completion of the transaction
set WAITCOUNT 15
# DHCP_WAIT:
sleep 1
if $IPADD seq \$IPADD goto DHCP_LOOP
echo "Received DHCP response."
echo "My IP Address is: $IPADD"
# If TFTPSRVR is set, ignore what DHCP gave us and always use this instead.
if $TFTPSRVR seq \$TFTPSRVR return
set BOOTSRVR "$TFTPSRVR"
return

# DHCP_LOOP:
# -d = decrement
set -d WAITCOUNT
if $WAITCOUNT gt 0 goto DHCP_WAIT
echo "No DHCP response received."
return

# ----------------------------------------------------------------------------

# FIND_ROOTFS:

# TRY_NFS:
if $ARG1 sne "nfs" goto TRY_CF
if $ARG2 seq \$ARG2 goto NO_OVERRIDE
set NFSSERVER "$ARG2"
if $ARG3 seq \$ARG3 goto NO_OVERRIDE
set NFSPATH "$ARG3"
# NO_OVERRIDE:
set CORE_ROOTDEV 0x0000
set ROOTFS_SPEC "nfsroot=$NFSSERVER:$NFSPATH,proto=tcp,nolock rw"
return

# TRY_CF:
if $ARG1 sne "cf" goto TRY_USB
set CORE_ROOTDEV 0x0301
set ROOTFS_SPEC "root=/dev/hda1 ro"
return

# TRY_USB:
if $ARG1 sne "usb" goto TRY_MMC
set CORE_ROOTDEV 0x0801
set ROOTFS_SPEC "root=/dev/sda1 ro root_delay=7"
return

# TRY_MMC:
if $ARG1 sne "sd" goto TRY_ROMFS
set CORE_ROOTDEV 0xfe01
set ROOTFS_SPEC "root=/dev/mmcblk0p1 ro"
return

# TRY_ROMFS:
if $ARG1 sne "rom" goto TRY_RAMFS
if $ARG2 seq \$ARG2 goto DO_ROMFS
set ROMFS "$ARG2"
# DO_ROMFS:
tfs base $ROMFS ROOTFS_BASE
if $ROOTFS_BASE seq \$ROOTFS_BASE goto NO_ROMFS
echo "Found romfs $ROMFS in TFS."
# ok, we found what looks like a filesystem in TFS,
# do some math to figure out its relative location
set ROOTFS_BASE=$ROOTFS_BASE-$BOOTROMBASE
tfs size $ROOTFS ROOTFS_SIZE
if $ROOTFS_SIZE seq \$ROOTFS_SIZE goto NO_ROMFS
set CORE_ROOTDEV 0x1f00
set ROOTFS_SPEC "mtdparts=flash00:$ROOTFS_SIZE@$ROOTFS_BASE(root)ro"
return
# NO_ROMFS:
echo "Couldn't find romfs $ROMFS in TFS."
exit

# TRY_RAMFS:
if $ARG1 sne "ram" goto USAGE
if $ARG2 seq \$ARG2 goto DO_RAMFS
set INITRD "$ARG2"
# DO_RAMFS:
set CORE_ROOTDEV 0x0100
set ROOTFS_SPEC "root=/dev/ram0 rw"
return

# USAGE:
echo "Unknown device \"$ARG1\"."
echo "Syntax: $ARG0 [[nfs|cf|usb|sd|rom|ram] [rootspec]]"
echo "rootspec: $ARG0 nfs [server-ip root-path]"
echo "rootspec: $ARG0 rom [filename]"
echo "rootspec: $ARG0 ram [filename]"
exit

# ----------------------------------------------------------------------------

# LOAD_INITRD:

tfs size $INITRD INITRD_SIZE
if $INITRD_SIZE seq \$INITRD_SIZE goto TRY_TFTP
echo "Found initrd $INITRD in TFS."
tfs cp $INITRD $INITRDBASE
set ROOTFS_SPEC "$ROOTFS_SPEC initrd=$INITRDBASE,$INITRD_SIZE"
return

# TRY_TFTP:
# Fail quietly and don't try TFTP if an initrd isn't required.
if $ARG1 sne "ram" return
tftp $BOOTSRVR get $INITRD $INITRDBASE
if $TFTPGET sne \$TFTPGET goto GOT_INITRD

# Last chance ...
tftp $BOOTSRVR get "$PLATFORM/$INITRD" $INITRDBASE
if $TFTPGET seq \$TFTPGET goto NO_RAMFS

# GOT_INITRD:
set ROOTFS_SPEC "$ROOTFS_SPEC initrd=$INITRDBASE,$TFTPGET"
return

# NO_RAMFS:
echo "Couldn't find initrd $INITRD in TFS or on $BOOTSRVR."
exit

# ----------------------------------------------------------------------------

# BUILD_ATAGS:

# build the basic ATAGS structure
ldatags -m -i core_pgsize=4096 core_flags=0 core_rootdev=$CORE_ROOTDEV mem32_size=$MEMSIZE mem32_start=$MEMBASE cmdline=

# Kernel IP autoconfiguration parameters
if $IPADD seq \$IPADD goto FB_OPTIONS
ldatags cmdline_append=" ip=$IPADD:$NFSSERVER:$GIPADD:$NETMASK::eth0:off"

# FB_OPTIONS:
# Sane value for framebuffer console
ldatags cmdline_append=" video=sm501fb:crt:1024x768-16@69,panel:off"

# Force serial console?
#ldatags cmdline_append=" console=ttyS0,$CONSOLEBAUD"

# add W1 GPIO Line
ldatags cmdline_append=" at91_w1_gpio_bus=0x45"

# add in the command line
ldatags cmdline_append=" $ROOTFS_SPEC"

# drag in any extra command line options from the environment
if "$CMDLINE_APPEND" seq \$CMDLINE_APPEND goto REPORT_CMDLINE
ldatags cmdline_append=" $CMDLINE_APPEND"

# REPORT_CMDLINE:
# display the ATAGS
ldatags -v cmdline_append=" "

# copy ATAGS to their proper place in memory
# (defined by arm-linux to be just after the zero page)
set ATAGS $APPRAMBASE
set -a ATAGS 0xf0000000
set -o ATAGS 0x100
cm -4 $APPRAMBASE $ATAGS 2048

return

# ----------------------------------------------------------------------------

# LOAD_KERNEL:

# look for a file named $KERNEL in TFS
tfs size $KERNEL KERNEL_SIZE
if $KERNEL_SIZE seq \$KERNEL_SIZE goto NO_KERNEL

echo "Found kernel $KERNEL in TFS."
tfs cp $KERNEL $APPRAMBASE
return

# NO_KERNEL:

# so far, no good; try TFTP server
tftp $BOOTSRVR get $KERNEL $APPRAMBASE
if $TFTPGET sne \$TFTPGET return

# that didn't work; try one other place before giving up
tftp $BOOTSRVR get "$PLATFORM/$KERNEL" $APPRAMBASE
if $TFTPGET sne \$TFTPGET return

echo "Couldn't find kernel $KERNEL in TFS or on $BOOTSRVR."
exit