# -*- mode: python; coding: utf-8; -*-

#  Codezero -- a microkernel for embedded systems.
#
#  Copyright © 2009  B Labs Ltd
#
#  This program is free software: you can redistribute it and/or modify it under the terms of the GNU
#  General Public License as published by the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
#  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
#  License for more details.
#
#  You should have received a copy of the GNU General Public License along with this program.  If not, see
#  <http://www.gnu.org/licenses/>.
#
#  Author: Russel Winder

import os.path
import subprocess

Import('environment', 'images', 'libsInOrder')

e = environment.Clone()
e.Append(LINKFLAGS = ['-T' + e['buildDirectory'] + '/loader/linker.lds'])
e.Append(LIBS = libsInOrder)
e.Append(CPPPATH = ['#libs/elf/include', '#' + e['buildDirectory'] + '/loader'])

def convertAddress(address):
    '''Convert the string representation of the address given as parameter to a string representation of the
    address without the top four bits set.  The issue here is that Python has a penchant for adding L to the
    end to create a Python literal.  This is not wanted here.'''
    value = hex(int(address, 16) - 0xf0000000)
    if value[-1] in ['l', 'L']:
        value = value[:-1]
    return value

def ksymToLds(target, source, env):
    symbols = ['break_virtual']
    with open(target[0].path, 'w') as asmFile:
        asmFile.write('''
/*
 * %s autogenerated from %s.
 *
 * This file is included by the loader sources so that any
 * kernel symbol address can be known in advance and stopped
 * at by debuggers before virtual memory is enabled.
 */
''' % (target[0].name, source[0].name))
        for symbol in symbols:
            process = subprocess.Popen('arm-none-eabi-objdump -d ' + source[0].path + ' | grep "<' + symbol + '>"', shell=True, stdout=subprocess.PIPE)
            assert process.wait() == 0
            address, name = process.stdout.read().split()
            assert '<' + symbol + '>:' == name
            asmFile.write( '''
.section .text
.align 4
.global %s
.type %s, function
.equ %s, %s
''' % (symbol, symbol, symbol, convertAddress(address)))


container_assembler_start = \
'''
.align 4
.section .kernel
.incbin "%s"
'''

container_assembler_body = \
'''
.align 4
.section .cont.%d
.incbin "%s"
'''

container_lds_start = \
'''/*
 * Autogenerated linker script that embeds each container image.
 *
 * Copyright (C) 2009 B Labs
 */

SECTIONS
{'''

container_lds_body = \
'''
	.cont.%d : { *(.cont.%d) }'''

container_lds_end = \
'''
}
'''

def generate_container_assembler(source, target, env):
    with open(target[0].path, "w+") as f:
        file_body = container_assembler_start % (str(source[0]))
        img_i = 0
        for img in source[1:]:
             file_body += container_assembler_body % (img_i, img)
             img_i += 1

        f.write(file_body)
        f.close()

def generate_container_lds(source, target, env):
     with open(target[0].path, "w+") as f:
        img_i = 0
        file_body = container_lds_start
        for img in source[1:]:
            file_body += container_lds_body % (img_i, img_i)
            img_i += 1
        file_body += container_lds_end
        f.write(file_body)
        f.close()

startAxfS = Command('start.axf.S', images[0], ksymToLds)

#  In the following, it is crucially important that the order of the sources is as it is -- assumptions are
#  made in the functions doing the processing.

kernelS = Command('containers.S', images, generate_container_assembler)
linkerScript = Command('linker.lds', images, generate_container_lds)

##  TODO:  deal with the situation where there are other .c and .S files in the directory.

objects = e.Object(['arch.c' , 'main.c', kernelS, startAxfS])
Depends(objects, e['configFiles'])
Depends(objects, images)
program = e.Program('final', objects + [e['baremetal_crt0']])
Depends(program, linkerScript)

Return('program')