add license; reorganize arch

.gitignore

@@ -1,6 +1,6 @@
-all
+kernel
-all.raw
+kernel.raw
-all.raw.gz
+kernel.raw.gz
 uimage
 *.o
 *.cc

Makefile

@@ -1,57 +1,54 @@
-load = 0x80000000
+# Iris: micro-kernel for a capability-based operating system.
+# Makefile: build rules
+# Copyright 2009 Bas Wijnen <wijnen@debian.org>
+#
+# 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/>.
 
-CXXFLAGS = -Wno-unused-parameter -fno-strict-aliasing -fno-builtin -nostdinc -DNUM_THREADS=2 -I/usr/include
+# Define some variables.
-CPPFLAGS = -O5 -Wa,-mips32
+CXXFLAGS = -Wno-unused-parameter -fno-strict-aliasing -fno-builtin -nostdinc $(ARCH_CXXFLAGS)
-CROSS = mipsel-linux-gnu-
+CPPFLAGS = -O5 $(ARCH_CPPFLAGS)
 CC = $(CROSS)gcc
 LD = $(CROSS)ld
 OBJCOPY = $(CROSS)objcopy
-OBJDUMP = $(CROSS)objdump
 STRIP = $(CROSS)strip
 
-kernel_sources = interrupts.cc panic.cc data.cc test.cc alloc.cc arch.cc invoke.cc schedule.cc
+headers = kernel.hh iris.h $(arch_headers)
-boot_sources = init.cc
+kernel_sources = panic.cc data.cc alloc.cc invoke.cc schedule.cc $(arch_kernel_sources)
 BUILT_SOURCES = $(kernel_sources) $(boot_sources)
 
+# Include arch-specific rules.
+include Makefile.arch
+
+# Disable implicit rules.
+%.o: %.S
+%.o: %.cc
+
 PYPP = /usr/bin/pypp
 %.cc: %.ccp
 	$(PYPP) --name $< < $< > $@
-%.hh: %.hhp boot-programs/sos.h
+%.hh: %.hhp
 	$(PYPP) --name $< < $< > $@
 
-# Transform ':' into ';' so vim doesn't think there are errors.
+%.o:%.cc Makefile Makefile.arch $(headers)
-uimage: all.raw Makefile
+	$(CC) $(CPPFLAGS) $(TARGET_FLAGS) $(CXXFLAGS) -c $< -o $@
-	mkimage -A MIPS -O Linux -C none -a $(load) -e 0x$(shell /bin/sh -c '$(OBJDUMP) -t all | grep __start$$ | cut -b-8') -n "Shevek's kernel" -d $< $@ | sed -e 's/:/;/g'
 
-arch.hh: mips.hh
+%: boot-programs/init.o boot-programs/%.o
-	ln -s $< $@ || true
-arch.cc: mips.cc
-	ln -s $< $@ || true
-
-%.o:%.cc Makefile kernel.hh arch.hh boot-programs/sos.h
-	$(CC) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
-
-entry.o: thread0 thread1
-
-%.o:%.S Makefile arch.hh
-	$(CC) $(CPPFLAGS) -DKERNEL_STACK_SIZE=0x2000 -c $< -o $@
-
-%: boot-helper.o boot-programs/%.o
 	$(LD) $^ -o $@
 	$(STRIP) $@
-
+	$(OBJCOPY) -S $(OBJCOPYFLAGS) $@
-# entry.o must be the first file.  boot.o must be the first of the init objects (which can be dumped after loading).
-all: entry.o $(subst .cc,.o,$(kernel_sources)) boot.o $(subst .cc,.o,$(boot_sources))
-	$(LD) --omagic -Ttext $(load) $^ -o $@
-
-junk = mdebug.abi32 reginfo comment pdr
-%.raw: %
-	$(OBJCOPY) -S $(addprefix --remove-section=.,$(junk)) -Obinary $< $@
-
-%.gz: %
-	gzip < $< > $@
 
 clean:
-	rm -f all uimage *.o boot-programs/*.o all.raw.gz arch.hh arch.cc
+	rm -f *.o boot-programs/*.o kernel kernel.raw kernel.raw.gz $(BUILT_SOURCES) $(ARCH_CLEAN_FILES)
 
 .PHONY: clean

Makefile.arch

@@ -0,0 +1 @@
+mips/Makefile.arch

alloc.ccp

@@ -1,4 +1,21 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// alloc.ccp: Allocation of kernel structures.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #include "kernel.hh"
 
 #define PREV(x) (((Object_base **)(x))[-2])

boot-helper.S

@@ -1,28 +0,0 @@
-	.globl __start
-
-__start:
-	bal 1f
-	.word _gp
-1:
-	lw $gp, 0($ra)
-	la $v0, __my_receiver
-	sw $a0, ($v0)
-	la $v0, __my_thread
-	sw $a1, ($v0)
-	la $v0, __my_memory
-	sw $a2, ($v0)
-	la $v0, __my_call
-	sw $a3, ($v0)
-	la $t9, main
-	la $ra, 1f
-	jr $t9
-	nop
-
-1:
-	// Generate an address fault.
-	lw $a0, -4($zero)
-
-	.comm __my_receiver, 4
-	.comm __my_thread, 4
-	.comm __my_memory, 4
-	.comm __my_call, 4

boot-programs/init.S

@@ -0,0 +1,47 @@
+// Iris: micro-kernel for a capability-based operating system.
+// init.S: Startup code for initial Threads.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+	.globl __start
+	.set noreorder
+
+__start:
+	bal 1f
+	.word _gp
+1:
+	lw $gp, 0($ra)
+	la $v0, __my_receiver
+	sw $a0, ($v0)
+	la $v0, __my_thread
+	sw $a1, ($v0)
+	la $v0, __my_memory
+	sw $a2, ($v0)
+	la $v0, __my_call
+	sw $a3, ($v0)
+	la $t9, main
+	la $ra, 1f
+	jr $t9
+	nop
+
+1:
+	// This should not be reached: generate an address fault.
+	b 1b
+	lw $a0, -4($zero)
+
+	.comm __my_receiver, 4
+	.comm __my_thread, 4
+	.comm __my_memory, 4
+	.comm __my_call, 4

boot-programs/thread0.ccp

@@ -1,5 +1,22 @@
 #pypp 0
-#include "sos.h"
+// Iris: micro-kernel for a capability-based operating system.
+// thread0.ccp: Testing userspace thread.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+#include "iris.h"
 
 int main ():
 	while true:

boot-programs/thread1.ccp

@@ -1,5 +1,22 @@
 #pypp 0
-#include "sos.h"
+// Iris: micro-kernel for a capability-based operating system.
+// thread1.ccp: Testing userspace thread.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+#include "iris.h"
 
 int main ():
 	while true:

boot.S

@@ -1,51 +0,0 @@
-	// The kernel stack.
-	.lcomm kernel_stack, KERNEL_STACK_SIZE
-
-	.globl __start
-	.globl thread_start
-	.set noreorder
-
-#define Status 12
-#define Config 16
-
-__start:
-	bal 1f
-	nop
-	.word _gp
-// For some reason the disassembler considers everything
-// after __start non-code until the next label.  So I add a label.
-start_hack_for_disassembler:
-1:	lw $gp, 0($ra)
-
-	la $sp, kernel_stack + KERNEL_STACK_SIZE
-
-	// Disable interrupts during bootstrap.
-	mtc0 $zero, $Status
-
-	// TODO: flush cache and optionally refill it.
-
-	// Set kseg0 cachable.
-	li $k0, 0x3
-	mtc0 $k0, $Config, 0
-
-	// Jump into cached code.
-	la $t9, 1f
-	jr $t9
-	nop
-1:
-
-	// Clear .bss
-	la $a0, _edata
-	la $a1, _end
-1:	sw $zero, 0($a0)
-	bne $a1, $a0, 1b
-	addu $a0, 4
-
-	la $t9, init
-	jr $t9
-	nop
-
-thread_start:
-	.word thread0
-	.word thread1
-	.word thread2

data.ccp

@@ -1,8 +1,27 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// data.ccp: Allocation of kernel structures.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+// All variables are defined in kernel.hhp as "EXTERN", which is normally
+// defined as "extern".  By defining it empty, space is allocated for them.
+// This must happen exactly once in all files linked into the kernel.
 #define EXTERN
 #include "kernel.hh"
 
-// This is needed to make gcc happy to compile c++ code without
+// This is needed to make gcc compile c++ code without its standard library.
-// its standard library.
 char __gxx_personality_v0[] = "hack"
 

invoke.ccp

@@ -1,4 +1,21 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// invoke.ccp: Capability invocation and kernel responses.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #include "kernel.hh"
 
 Capability *Memory::find_capability (unsigned code, bool *copy):

iris.h

@@ -1,5 +1,22 @@
-#ifndef __SOS_H
+/* Iris: micro-kernel for a capability-based operating system.
-#define __SOS_H
+ * iris.h: C header file for userspace programs.
+ * Copyright 2009 Bas Wijnen <wijnen@debian.org>
+ *
+ * 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/>.
+ */
+#ifndef __IRIS_H
+#define __IRIS_H
 
 #ifdef __cplusplus
 extern "C" {

kernel.hhp

@@ -1,14 +1,38 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// kernel.hhp: Header for all kernel sources.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #ifndef _KERNEL_HH
 #define _KERNEL_HH
 
+// Include definitions which are shared with user space.
 #define __KERNEL
-#include "boot-programs/sos.h"
+#include "iris.h"
 
+// Normally define all variables in this file as extern.
+// Exactly once (in data.ccp), EXTERN is predefined empty.
+// That results in space being allocated in its object file.
 #ifndef EXTERN
 #define EXTERN extern
 #endif
 
+// Without the standard library, we don't have this definition.
+// I preferred ((void*)0), but C++ has too strict type-checking to
+// make that work.
 #define NULL 0
 
 struct Object_base
@@ -38,6 +62,7 @@ struct Free : public Object <Free>:
 bool Object_base::is_free ():
 	return ((Free *)this)->marker == ~0
 
+// Include architecture-specific parts.
 #include "arch.hh"
 
 struct Thread : public Object <Thread>:
@@ -167,7 +192,7 @@ EXTERN Thread *current
 unsigned raw_zalloc ()
 void raw_pfree (unsigned page)
 
-// Defined in arch.cc
+// Defined by architecture-specific files.
 void Thread_arch_init (Thread *thread)
 void Thread_arch_receive (Thread *thread, unsigned d[4], Capability *c[4])
 void Thread_arch_receive_fail (Thread *thread)

mips/Makefile.arch

@@ -0,0 +1,59 @@
+# Iris: micro-kernel for a capability-based operating system.
+# mips/Makefile.arch: mips-specific parts of the build rules
+# Copyright 2009 Bas Wijnen <wijnen@debian.org>
+#
+# 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/>.
+
+load = 0x80000000
+
+ARCH_CXXFLAGS = -DNUM_THREADS=2
+ARCH_CPPFLAGS = -Imips -Wa,-mips32
+CROSS = mipsel-linux-gnu-
+OBJDUMP = $(CROSS)objdump
+junk = mdebug.abi32 reginfo comment pdr
+OBJCOPYFLAGS = $(addprefix --remove-section=.,$(junk))
+
+arch_kernel_sources = mips/interrupts.cc mips/test.cc mips/arch.cc
+boot_sources = mips/init.cc
+BUILT_SOURCES = $(kernel_sources) $(boot_sources)
+arch_headers = mips/arch.hh
+boot_threads = thread0 thread1
+
+uimage:
+
+mips/entry.o: $(boot_threads)
+mips/init.o: TARGET_FLAGS = -I/usr/include
+$(boot_threads): TARGET_FLAGS = -I.
+
+# Transform ':' into ';' so vim doesn't think there are errors.
+uimage: kernel.raw.gz Makefile mips/Makefile.arch
+	mkimage -A MIPS -O Linux -C gzip -a $(load) -e 0x$(shell /bin/sh -c '$(OBJDUMP) -t kernel | grep __start$$ | cut -b-8') -n "Shevek's kernel" -d $< $@ | sed -e 's/:/;/g'
+
+elf.h: /usr/include/elf.h
+	ln -s $< $@
+
+%.o:%.S Makefile mips/Makefile.arch mips/arch.hh
+	$(CC) $(CPPFLAGS) $(TARGET_FLAGS) -DKERNEL_STACK_SIZE=0x2000 -c $< -o $@
+
+# entry.o must be the first file.  boot.o must be the first of the init objects (which can be freed after loading).
+kernel: mips/entry.o $(subst .cc,.o,$(kernel_sources)) mips/boot.o $(subst .cc,.o,$(boot_sources))
+	$(LD) --omagic -Ttext $(load) $^ -o $@
+
+%.raw: %
+	$(OBJCOPY) -S $(addprefix --remove-section=.,$(junk)) -Obinary $< $@
+
+%.gz: %
+	gzip < $< > $@
+
+ARCH_CLEAN_FILES = uimage kernel kernel.raw kernel.raw.gz elf.h $(boot_threads) mips/*.o

mips/arch.ccp

@@ -1,6 +1,23 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// mips/arch.ccp: Most mips-specific parts.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #define ARCH
-#include "kernel.hh"
+#include "../kernel.hh"
 
 void Thread_arch_init (Thread *thread):
 	thread->arch.at = 0

mips/arch.hhp

@@ -1,4 +1,21 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// mips/arch.hhp: mips-specific declarations and type definitions.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #ifndef _ARCH_HH
 #define _ARCH_HH
 

mips/boot.S

@@ -0,0 +1,68 @@
+// Iris: micro-kernel for a capability-based operating system.
+// mips/boot.S: Kernel entry point, called by the boot loader.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+	// The kernel stack.
+	.lcomm kernel_stack, KERNEL_STACK_SIZE
+
+	.globl __start
+	.globl thread_start
+	.set noreorder
+
+#define Status 12
+#define Config 16
+
+__start:
+	bal 1f
+	nop
+	.word _gp
+// For some reason the disassembler considers everything
+// after __start non-code until the next label.  So I add a label.
+start_hack_for_disassembler:
+1:	lw $gp, 0($ra)
+
+	la $sp, kernel_stack + KERNEL_STACK_SIZE
+
+	// Disable interrupts during bootstrap.
+	mtc0 $zero, $Status
+
+	// TODO: flush cache and optionally refill it.
+
+	// Set kseg0 cachable.
+	li $k0, 0x3
+	mtc0 $k0, $Config, 0
+
+	// Jump into cached code.
+	la $t9, 1f
+	jr $t9
+	nop
+1:
+
+	// Clear .bss
+	la $a0, _edata
+	la $a1, _end
+1:	sw $zero, 0($a0)
+	bne $a1, $a0, 1b
+	addu $a0, 4
+
+	la $t9, init
+	jr $t9
+	nop
+
+thread_start:
+	.word thread0
+	.word thread1
+	.word thread2

mips/entry.S

@@ -1,3 +1,20 @@
+// Iris: micro-kernel for a capability-based operating system.
+// mips/entry.S: Routines which are entered from user space.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 	// The kernel stack.
 	.lcomm kernel_stack, KERNEL_STACK_SIZE
 

mips/init.ccp

@@ -1,9 +1,26 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// init.ccp: mips-specific boot code.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 // Also declare things which only work during kernel init.
 #define INIT
 #define ARCH
-#include "kernel.hh"
+#include "../kernel.hh"
-#include "elf.h"
+#include <elf.h>
 
 static void init_idle ():
 	// initialize idle task as if it is currently running.

mips/interrupts.ccp

@@ -1,6 +1,23 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// interrupts.ccp: Functions called by mips/entry.S.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #define ARCH
-#include "kernel.hh"
+#include "../kernel.hh"
 
 /// A TLB miss has occurred.  This is the slow version.  It is only used
 /// when k0 or k1 is not 0, or when an error occurs.

mips/test.ccp

@@ -1,5 +1,22 @@
 #pypp 0
-#include "kernel.hh"
+// Iris: micro-kernel for a capability-based operating system.
+// test.ccp: Telling the user things with LEDs.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
+#include "../kernel.hh"
 
 #define REG32(addr)    *((volatile unsigned int *)(addr))
 

panic.ccp

@@ -1,4 +1,21 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// panic.ccp: Stop running and try to notify the user of the problem.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #include "kernel.hh"
 
 void panic (unsigned n, char const *message):

report/cross-compiler.tex

@@ -1,3 +1,20 @@
+% Iris: micro-kernel for a capability-based operating system.
+% cross-compiler.tex: Cross-compiler building instructions.
+% Copyright 2009 Bas Wijnen <wijnen@debian.org>
+%
+% 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/>.
+
 \documentclass{shevek}
 \begin{document}
 \title{Setting up a cross-compiler}

report/kernel.tex

@@ -1,16 +1,33 @@
+% Iris: micro-kernel for a capability-based operating system.
+% kernel.tex: Description of Iris.
+% Copyright 2009 Bas Wijnen <wijnen@debian.org>
+%
+% 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/>.
+
 \documentclass{shevek}
 \begin{document}
-\title{Overview of my kernel}
+\title{Overview of Iris}
 \author{Bas Wijnen}
 \date{\today}
 \maketitle
 \begin{abstract}
-This document briefly describes the inner workings of my kernel, including the
+This document briefly describes the inner workings of my kernel, Iris,
-reasons for the choices that were made.  It is meant to be understandable (with
+including the reasons for the choices that were made.  It is meant to be
-effort) for people who know nothing of operating systems.  On the other hand,
+understandable (with effort) for people who know nothing of operating systems.
-it should also be readable for people who know about computer architecture, but
+On the other hand, it should also be readable for people who know about
-want to know about this kernel.  It is probably better suited for the latter
+computer architecture, but want to know about this kernel.  It is probably
-category.
+better suited for the latter category.
 \end{abstract}
 
 \tableofcontents
@@ -20,7 +37,7 @@ This section describes what the purpose of an operating system is, and defines
 what I call an ``operating system''\footnote{Different people use very
 different definitions, so this is not as trivial as it sounds.}.  It also goes
 into some detail about microkernels and capabilities.  If you already know, you
-can safely skip this section.  It contains no information about my kernel.
+can safely skip this section.  It contains no information about Iris.
 
 \subsection{The goal of an operating system}
 In the 1980s, a computer could only run one program at a time.  When the
@@ -160,8 +177,8 @@ into the hands of the user (as far as allowed by the system administrator).
 This is a very good thing.
 
 \section{Kernel objects}
-This section describes all the kernel objects, and the operations that can be
+This section describes all kernel objects of Iris, and the operations that can
-performed on them.  One operation is possible on any kernel object (except a
+be performed on them.  One operation is possible on any kernel object (except a
 message and reply and call Capabilities).  This operation is \textit{degrade}.
 It creates a copy of the capability with some rights removed.  This can be
 useful when giving away a capability.
@@ -191,13 +208,13 @@ Receiver's queues.
 \item Get and set the limit, which is checked when allocating pages for this
 Memory or any sub-structure.
 \item Drop a capability.  This can only be done by Threads owned by the Memory,
-because only they can present capabilities owned by it.\footnote{The kernel
+because only they can present capabilities owned by it.\footnote{Iris checks if
-checks if presented capabilities are owned by the Thread's Memory.  If they
+presented capabilities are owned by the Thread's Memory.  If they aren't, no
-aren't, no capability is passed instead.  The destroy operation destroys an
+capability is passed instead.  The destroy operation destroys an object that a
-object that a capability points to.  Drop destroys the capability itself.  If a
+capability points to.  Drop destroys the capability itself.  If a Thread from
-Thread from an other Memory would try to drop a capability, the kernel would
+an other Memory would try to drop a capability, Iris would refuse to send it in
-refuse to send it in the message, or it would not be dropped because it would
+the message, or it would not be dropped because it would be owned by a
-be owned by a different Memory.}
+different Memory.}
 \end{itemize}
 
 \subsection{Receiver}
@@ -249,15 +266,15 @@ flags (whether the process is running or waiting for a message, setting these
 flags is a way to control this for other Threads), the program counter and the
 stack pointer.  This call is also used to get the contents of processor
 registers and possibly other information which is different per Thread.
-\item Let the kernel schedule the next process.  This is not thread-specific.
+\item Let Iris schedule the next process.  This is not thread-specific.
 \item Get the top Memory object.  This is not thread-specific.  Most Threads
 are not allowed to perform this operation.  It is given to the initial Threads.
 They can pass it on to Threads that need it (mostly device drivers).
 \item In the same category, register a Receiver for an interrupt.  Upon
 registration, the interrupt is enabled.  When the interrupt arrives, the
-registered Receiver gets a message from the kernel and the interrupt is
+registered Receiver gets a message from Iris and the interrupt is disabled
-disabled again.  After the Thread has handled the interrupt, it must reregister
+again.  After the Thread has handled the interrupt, it must reregister it in
-it in order to enable it again.
+order to enable it again.
 \item And similarly, allow these priviledged operations (or some of them) in an
 other thread.  This is a property of the caller, because the target thread
 normally doesn't have the permission to do this (otherwise the call would not
@@ -286,8 +303,8 @@ all flags can be set in all cases.
 \end{itemize}
 
 \subsection{Capability}
-A capability object can be invoked to send a message to a receiver or the
+A capability object can be invoked to send a message to a receiver or to Iris
-kernel.  The owner cannot see from the capability where it points.  This is
+itself.  The owner cannot see from the capability where it points.  This is
 important, because the user must be able to substitute the capability for a
 different one, without the program noticing.  In some cases, it is needed to
 say things about capabilities.  For example, a Memory can list the Capabilities

report/making-of.tex

@@ -1,3 +1,19 @@
+% Iris: micro-kernel for a capability-based operating system.
+% making-of.tex: Description of the process of writing Iris.
+% Copyright 2009 Bas Wijnen <wijnen@debian.org>
+%
+% 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/>.
 \documentclass{shevek}
 \begin{document}
 \title{Writing a kernel from scratch}
@@ -5,13 +21,13 @@
 \date{\today}
 \maketitle
 \begin{abstract}
-This is a report of the process of writing a kernel from scratch for
+This is a report of the process of writing a kernel (Iris) from scratch for
 the cheap (€150) Trendtac laptop.  In a following report I shall write about
-the operating system on top of it.  It is written while writing the system, so
+the operating system on top of it.  This document is written while writing the
-that no steps are forgotten.  Choices are explained and problems (and their
+system, so that no steps are forgotten.  Choices are explained and problems
-solutions) are shown.  After reading this, you should have a thorough
+(and their solutions) are shown.  After reading this, you should have a
-understanding of the kernel, and (with significant effort) be able to write a
+thorough understanding of Iris, and (with significant effort) be able to write
-similar kernel yourself.  This document assumes a working Debian system with
+a similar kernel yourself.  This document assumes a working Debian system with
 root access (for installing packages), and some knowledge about computer
 architectures.  (If you lack that knowledge, you can try to read it anyway and
 check other sources when you see something new.)
@@ -67,7 +83,9 @@ mapped (meaning it accesses physical, not virtual, memory)
 except that is is not cached.
 \item kseg2 runs from 0xc0000000 to the top.  It is mapped like user memory,
 differently for each process, and can be cached.  It is intended for
-per-address space kernel structures.  I shall not use it in my kernel.
+per-address space kernel structures.  I shall not use it in Iris.\footnote{I
+thought I wouldn't use kseg2.  However, I needed to use it for kernel entry
+code, as you can read below.}
 \end{itemize}
 U-boot has some standard commands.  It can load the image from the SD card at
 0x80600000.  Even though the Linux image seems to use a different address, I'll
@@ -181,7 +199,7 @@ It explains that memory accesses to the lower 2GB are (almost always) mapped
 through a TLB (translation lookaside buffer).  This is an array of some records
 where virtual to physical address mappings are stored.  In case of a TLB-miss
 (the virtual address cannot be found in the table), an exception is generated
-and the kernel must insert the mapping into the TLB.
+and Iris must insert the mapping into the TLB.
 
 This is very flexible, because I get to decide how I write the kernel.  I shall
 use something similar to the hardware implementation of the IBM PC: a page
@@ -197,16 +215,16 @@ what is more expensive.  I'll initially go for the cpu time wasting approach.
 
 \section{Kernel entry}
 Now that I have an idea of how a process looks in memory, I need to implement
-kernel entry and exit.  A process is preempted or makes a request, then the
+kernel entry and exit.  A process is preempted or makes a request, then Iris
-kernel responds, and then a process (possibly the same) is started again.
+responds, and then a process (possibly the same) is started again.
 
 The main problem of kernel entry is to save all registers in the kernel
 structure which is associated with the thread.  In case of the MIPS processor,
 there is a simple solution: there are two registers, k0 and k1, which cannot be
 used by the thread.  So they can be set before starting the thread, and will
-still have their values when the kernel is entered again.  By pointing one of
+still have their values when the kernel is entered again.\footnote{This is not
-them to the place to save the data, it becomes easy to perform the save and
+true, see below.}  By pointing one of them to the place to save the data, it
-restore.
+becomes easy to perform the save and restore.
 
 As with the bootstrap process, this must be done in assembly.  In this case
 this is because the user stack must not be used, and a C function will use the
@@ -221,12 +239,12 @@ easiest way.
 Now I've reached the point where I need to create some memory structures.  To
 do that, I first need to decide how to organize the memory.  There's one very
 simple rule in my system: everyone must pay for what they use.  For memory,
-this means that a process brings its own memory where the kernel can write
+this means that a process brings its own memory where Iris can write things
-things about it.  The kernel does not need its own allocation system, because
+about it.  Iris does not need her own allocation system, because she always
-it always works for some process.  If the process doesn't provide the memory,
+works for some process.  If the process doesn't provide the memory, the
-the operation will fail.\footnote{There are some functions with \textit{alloc}
+operation will fail.\footnote{There are some functions with \textit{alloc} in
-in their name.  However, they allocate pieces of memory which is owned by the
+their name.  However, they allocate pieces of memory which is owned by the
-calling process.  The kernel never allocates anything for itself, except during
+calling process.  Iris never allocates anything for herself, except during
 boot.}
 
 Memory will be organized hierarchically.  It belongs to a container, which I
@@ -235,11 +253,11 @@ Memory, its parent.  This is true for all but one, which is the top level
 Memory.  The top level Memory owns all memory in the system.  Some of it
 directly, most of it through other Memories.
 
-The kernel will have a list of unclaimed pages.  For optimization, it actually
+Iris will have a list of unclaimed pages.  For optimization, she actually
-has two lists: one with pages containing only zeroes, one with pages containing
+has two lists: one with pages containing only zeroes, and one with pages
-junk.  When idle, the junk pages can be filled with zeroes.
+containing junk.  When idle, the junk pages can be filled with zeroes.
 
-Because the kernel starts at address 0, building up the list of pages is very
+Because Iris starts at address 0, building up the list of pages is very
 easy: starting from the first page above the top of the kernel, everything is
 free space.  Initially, all pages are added to the junk list.
 
@@ -251,7 +269,7 @@ task, and then jumping to it.
 
 There are two options for the idle task, again with their own drawbacks.  The
 idle task can run in kernel mode.  This is easy, it doesn't need any paging
-machinery then.  However, this means that the kernel must read-modify-write the
+machinery then.  However, this means that Iris must read-modify-write the
 Status register of coprocessor 0, which contains the operating mode, on every
 context switch.  That's quite an expensive operation for such a critical path.
 
@@ -286,16 +304,17 @@ first switch off all interrupts by writing 0 to the Status register of CP0.
 This also reminded me that I need to flush the cache, so that I can be sure
 everything is correct.  For that reason, I need to start at 0xa0000000, not
 0x80000000, so that the startup code is not cached.  It should be fine to load
-the kernel at 0x80000000, but jump in at the non-cached location anyway, if I
+Iris at 0x80000000, but jump in at the non-cached location anyway, if I
 make sure the initial code, which clears the cache, can handle it.  After that,
 I jump to the cached region, and everything should be fine.  However, at this
-moment I first link the kernel at the non-cached address, so I don't need to
+moment I first link Iris at the non-cached address, so I don't need to
-worry about it.
+worry about it.\footnote{Actually, it seems that the cache is working fine, and
+I'm using the cached address.  They are used for kernel entry in any case.}
 
 Finally, I read in the books that k0 and k1 are in fact normal general purpose
 registers.  So while they are by convention used for kernel purposes, and
-compilers will likely not touch them, the kernel can't actually rely on them
+compilers will likely not touch them, Iris can't actually rely on them not
-not being changed by user code.  So I'll need to use a different approach for
+being changed by user code.  So I'll need to use a different approach for
 saving the processor state.  The solution is trivial: use k1 as before, but
 first load it from a fixed memory location.  To be able to store k1 itself, a
 page must be mapped in kseg3 (wired into the tlb), which can then be accessed
@@ -350,15 +369,15 @@ So now I need to accept calls from programs and handle them.  For this, I need
 to decide what such a call looks like.  It will need to send a capability to
 invoke, and a number of capabilities and numbers as arguments.  I chose to send
 four capabilities (so five in total) and also four numbers.  The way to send
-these is by setting registers before making a system call.  Similarly, when the
+these is by setting registers before making a system call.  Similarly, when
-kernel returns a message, it sets the registers before returing to the program.
+Iris returns a message, she sets the registers before returing to the program.
 
 I wrote one file with assembly for receiving interrupts and exceptions
 (including system calls) and one file with functions called from this assembly
 to do most of the work.  For syscall, I call an arch-specific\footnote{I split
 off all arch-specific parts into a limited number of files.  While I am
-currently writing the kernel only for the Trendtac, I'm trying to make it easy
+currently writing Iris only for the Trendtac, I'm trying to make it easy to
-to port it to other machines later.} invoke function, which reads the message,
+port her to other machines later.} invoke function, which reads the message,
 puts it in variables, and calls the real invoke function.
 
 The real invoke function analyzes the called capability: if it is in page 0
@@ -449,9 +468,9 @@ but can be reused.
 Another nice optimization is \textit{copy on write}: a page is shared
 read-only, and when a page-fault happens, the kernel will copy the contents, so
 that the other owner(s) don't see the changes.  For the moment, I don't
-implemnt this.  I'm not sure if I want it in the kernel at all.  It can well be
+implemnt this.  I'm not sure if I want it in Iris at all.  It can well be
-implemented using an exception handler in user space, and is not used enough to
+implemented using an exception handler in user space, and may not be used
-spend kernel space on, I think.  But I can change my mind on that later.
+enough to spend kernel space on.  But I can change my mind on that later.
 
 \section{Memory listing}
 The last thing to do for now is allowing a memory to be listed.  That is,
@@ -459,4 +478,14 @@ having a suitably priviledged capability to a Memory should allow a program to
 see what's in it.  In particular, what objects it holds, and where pages are
 mapped.  Probably also what messages are in a receiver's queue.
 
+\section{A name for the kernel}
+However, at this point I am publishing the existence of the kernel, and so I
+need to give it a name.  I like Greek mythology, so I decided to make it a
+Greek god.  Because the kernel is mostly doing communication between programs,
+while the programs do the real work on the system, I thought of Hermes, the
+messenger of the gods.  However, I don't really like his name, and I want a
+logo which is furrier than a winged boot or staff.  So I chose Iris, who is
+also a messenger of gods, but she has a rainbow symbol.  This is much nicer for
+creating a logo.
+
 \end{document}

schedule.ccp

@@ -1,4 +1,21 @@
 #pypp 0
+// Iris: micro-kernel for a capability-based operating system.
+// schedule.ccp: Thread scheduling.
+// Copyright 2009 Bas Wijnen <wijnen@debian.org>
+//
+// 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/>.
+
 #include "kernel.hh"
 
 void Thread::run ():