set script_dir [file dirname [file normalize [info script]]]
set fpga_dir [file normalize [file join $script_dir ../..]]

proc getenv_default {name default} {
  if {[info exists ::env($name)] && $::env($name) ne ""} {
    return $::env($name)
  }
  return $default
}

proc region_end {offset file} {
  return [expr {$offset + [file size $file]}]
}

set bit_file [file normalize [getenv_default BIT_FILE [file join $fpga_dir out bitstream genesys2_rocket.bit]]]
set app_image [file normalize [getenv_default APP_FLASH_IMAGE [file join $fpga_dir out flash hello_uart.flash.bin]]]
set mcs_file [file normalize [getenv_default FLASH_MCS [file join $fpga_dir out flash genesys2_rocket.mcs]]]
set bin_file [file normalize [getenv_default FLASH_BIN [file join $fpga_dir out flash genesys2_rocket.bin]]]
set flash_size_mb [getenv_default FLASH_SIZE_MB 32]
set flash_interface [getenv_default FLASH_INTERFACE SPIx4]
set bitstream_offset [getenv_default BITSTREAM_OFFSET 0x00000000]
set app_flash_offset [getenv_default APP_FLASH_OFFSET 0x01800000]
set assistance_flash_offset [getenv_default ASSISTANCE_FLASH_OFFSET 0x01f80000]
set assistance_flash_size [getenv_default ASSISTANCE_FLASH_SIZE 0x00080000]

file mkdir [file dirname $mcs_file]
file mkdir [file dirname $bin_file]

if {![file exists $bit_file]} {
  error "Bitstream not found: $bit_file"
}
if {![file exists $app_image]} {
  error "Application flash image not found: $app_image"
}

set flash_size_bytes [expr {$flash_size_mb * 1024 * 1024}]
set bitstream_end [region_end $bitstream_offset $bit_file]
set app_end [region_end $app_flash_offset $app_image]
set assistance_end [expr {$assistance_flash_offset + $assistance_flash_size}]
if {$bitstream_end > $flash_size_bytes} {
  error [format "Bitstream region exceeds flash: end=0x%08x flash_size=0x%08x" $bitstream_end $flash_size_bytes]
}
if {$app_end > $flash_size_bytes} {
  error [format "App region exceeds flash: end=0x%08x flash_size=0x%08x" $app_end $flash_size_bytes]
}
if {$assistance_end > $flash_size_bytes} {
  error [format "GPS assistance reservation exceeds flash: end=0x%08x flash_size=0x%08x" $assistance_end $flash_size_bytes]
}
if {$bitstream_offset < $assistance_end && $assistance_flash_offset < $bitstream_end} {
  error [format "Bitstream overlaps GPS assistance reservation: bit=[0x%08x,0x%08x) assistance=[0x%08x,0x%08x)" \
    $bitstream_offset $bitstream_end $assistance_flash_offset $assistance_end]
}
if {$app_flash_offset < $assistance_end && $assistance_flash_offset < $app_end} {
  error [format "App overlaps GPS assistance reservation: app=[0x%08x,0x%08x) assistance=[0x%08x,0x%08x)" \
    $app_flash_offset $app_end $assistance_flash_offset $assistance_end]
}
if {$bitstream_offset < $app_end && $app_flash_offset < $bitstream_end} {
  error [format "Bitstream/app flash regions overlap: bit=[0x%08x,0x%08x) app=[0x%08x,0x%08x)" \
    $bitstream_offset $bitstream_end $app_flash_offset $app_end]
}

puts "Generating flash MCS:"
puts "  bitstream: $bit_file @ $bitstream_offset"
puts "  app image: $app_image @ $app_flash_offset"
puts "  size/interface: ${flash_size_mb}MiB $flash_interface"
puts [format "  flash size: 0x%08x bytes" $flash_size_bytes]
puts [format "  bitstream end: 0x%08x" $bitstream_end]
puts [format "  app end: 0x%08x" $app_end]
puts [format "  assistance reserved: 0x%08x-0x%08x" $assistance_flash_offset $assistance_end]

write_cfgmem -force -format MCS -size $flash_size_mb -interface $flash_interface \
  -loadbit "up $bitstream_offset $bit_file" \
  -loaddata "up $app_flash_offset $app_image" \
  $mcs_file

write_cfgmem -force -format BIN -size $flash_size_mb -interface $flash_interface \
  -loadbit "up $bitstream_offset $bit_file" \
  -loaddata "up $app_flash_offset $app_image" \
  $bin_file

puts "Wrote $mcs_file"
puts "Wrote $bin_file"