1
0
Fork 0
mirror of https://gitlab.com/sortix/sortix.git synced 2023-02-13 20:55:38 -05:00
sortix--sortix/kernel/kernel.cpp
Jonas 'Sortie' Termansen 01a9779fc6 Compile libc with -ffreestanding.
This properly avoids problems where the compiler is unaware that this is the
implementation and assumes it can rely on the implementation. For instance,
it might implement calloc using a call to calloc.

Restructure the code that wrongly assumed __STDC_HOSTED__ meant userspace.
2016-05-15 22:43:29 +02:00

678 lines
21 KiB
C++

/*
* Copyright (c) 2011, 2012, 2013, 2014, 2015 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* kernel.cpp
* The main kernel initialization routine. Configures hardware and starts an
* initial process from the init ramdisk, allowing a full operating system.
*/
#include <sys/types.h>
#include <assert.h>
#include <brand.h>
#include <ctype.h>
#include <elf.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sortix/fcntl.h>
#include <sortix/mman.h>
#include <sortix/stat.h>
#include <sortix/wait.h>
#include <sortix/kernel/copy.h>
#include <sortix/kernel/decl.h>
#include <sortix/kernel/descriptor.h>
#include <sortix/kernel/dtable.h>
#include <sortix/kernel/fcache.h>
#include <sortix/kernel/inode.h>
#include <sortix/kernel/interrupt.h>
#include <sortix/kernel/ioctx.h>
#include <sortix/kernel/keyboard.h>
#include <sortix/kernel/kthread.h>
#include <sortix/kernel/log.h>
#include <sortix/kernel/memorymanagement.h>
#include <sortix/kernel/mtable.h>
#include <sortix/kernel/panic.h>
#include <sortix/kernel/pci.h>
#include <sortix/kernel/process.h>
#include <sortix/kernel/ptable.h>
#include <sortix/kernel/refcount.h>
#include <sortix/kernel/scheduler.h>
#include <sortix/kernel/signal.h>
#include <sortix/kernel/string.h>
#include <sortix/kernel/textbuffer.h>
#include <sortix/kernel/thread.h>
#include <sortix/kernel/time.h>
#include <sortix/kernel/user-timer.h>
#include <sortix/kernel/video.h>
#include <sortix/kernel/vnode.h>
#include <sortix/kernel/worker.h>
#include "com.h"
#include "disk/ahci/ahci.h"
#include "disk/ata/ata.h"
#include "fs/full.h"
#include "fs/kram.h"
#include "fs/null.h"
#include "fs/random.h"
#include "fs/zero.h"
#include "gpu/bga/bga.h"
#include "initrd.h"
#include "kb/default-kblayout.h"
#include "kb/kblayout.h"
#include "kb/ps2.h"
#include "logterminal.h"
#include "mouse/ps2.h"
#include "multiboot.h"
#include "net/fs.h"
#include "poll.h"
#include "uart.h"
#include "vga.h"
#if defined(__i386__) || defined(__x86_64__)
#include "x86-family/cmos.h"
#include "x86-family/float.h"
#include "x86-family/gdt.h"
#include "x86-family/ps2.h"
#endif
// Keep the stack size aligned with $CPU/boot.s
const size_t STACK_SIZE = 64*1024;
extern "C" { __attribute__((aligned(16))) size_t stack[STACK_SIZE / sizeof(size_t)]; }
namespace Sortix {
// Forward declarations.
static void BootThread(void* user);
static void InitThread(void* user);
static void SystemIdleThread(void* user);
static multiboot_info_t* bootinfo;
static char* init_cmdline;
static char* cmdline_tokenize(char** saved)
{
char* data = *saved;
if ( !data )
return *saved = NULL;
while ( data[0] && isspace((unsigned char) data[0]) )
data++;
if ( !data[0] )
return *saved = NULL;
size_t input = 0;
size_t output = 0;
bool singly = false;
bool doubly = false;
bool escaped = false;
for ( ; data[input]; input++ )
{
char c = data[input];
if ( !escaped && !singly && !doubly && isspace((unsigned char) c) )
break;
if ( !escaped && !doubly && c == '\'' )
{
singly = !singly;
continue;
}
if ( !escaped && !singly && c == '"' )
{
doubly = !doubly;
continue;
}
if ( !singly && !escaped && c == '\\' )
{
escaped = true;
continue;
}
escaped = false;
data[output++] = c;
}
if ( data[input] )
*saved = data + input + 1;
else
*saved = NULL;
data[output] = '\0';
return data;
}
extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo_p)
{
(void) magic;
bootinfo = bootinfo_p;
//
// Stage 1. Initialization of Early Environment.
//
// TODO: Call global constructors using the _init function.
// Detect available physical memory.
Memory::Init(bootinfo);
// Initialize the kernel log.
Log::Init(bootinfo);
// Display the logo.
Log::PrintF("\e[37;41m\e[2J");
Log::Center(BRAND_LOGO);
#if defined(__x86_64__)
// TODO: Remove this hack when qemu 1.4.x and 1.5.0 are obsolete.
// Verify that we are not running under a buggy qemu where the instruction
// movl (%eax), %esi is misinterpreted (amongst others). In this case it
// will try to access the memory at [bx + si]. We'll make sure that eax
// points to a variable on the stack that has another value than at bx + si,
// and if the values compare equal using the buggy instruction, we panic.
uint32_t intended_variable; // rax will point to here.
uint32_t is_buggy_qemu;
asm ("movq $0x1000, %%rbx\n" /* access 32-bit value at 0x1000 */
"movl (%%rbx), %%esi\n"
"subl $1, %%esi\n" /* change the 32-bit value */
"movl %%esi, (%%rax)\n" /* store the new value in intended_variable */
"movq $0x0, %%rsi\n" /* make rsi zero, so bx + si points to 0x1000 */
"movl (%%eax), %%esi\n" /* do the perhaps-buggy memory access */
"movl (%%rax), %%ebx\n" /* do a working memory access */
"movl %%ebx, %0\n" /* load the desired value into is_buggy_qemu */
"subl %%esi, %0\n" /* subtract the possibly incorrect value. */
: "=r"(is_buggy_qemu)
: "a"(&intended_variable)
: "rsi", "rbx");
if ( is_buggy_qemu )
Panic("You are running a buggy version of qemu. The 1.4.x and 1.5.0 "
"releases are known to execute some instructions incorrectly on "
"x86_64 without KVM. You have three options: 1) Enable KVM 2) "
"Use a 32-bit OS 3) Use another version of qemu.");
#endif
char* cmdline = NULL;
if ( bootinfo->flags & MULTIBOOT_INFO_CMDLINE && bootinfo->cmdline )
{
addr_t physical_from = Page::AlignDown(bootinfo->cmdline);
size_t offset = bootinfo->cmdline - physical_from;
size_t desired = 16 * Page::Size();
size_t mapped = offset + desired;
addralloc_t alloc;
if ( !AllocateKernelAddress(&alloc, mapped) )
Panic("Failed to allocate virtual space for command line");
for ( size_t i = 0; i < mapped; i += Page::Size() )
{
if ( !Memory::Map(physical_from + i, alloc.from + i, PROT_KREAD) )
Panic("Failed to memory map command line");
}
char* bootloader_cmdline = (char*) (alloc.from + offset);
size_t cmdline_length = strnlen(bootloader_cmdline, desired);
if ( desired <= cmdline_length )
Panic("Kernel command line is too long");
if ( !(cmdline = strdup(bootloader_cmdline)) )
Panic("Failed to strdup command line");
for ( size_t i = 0; i < mapped; i += Page::Size() )
Memory::Unmap(alloc.from + i);
Memory::Flush();
FreeKernelAddress(&alloc);
}
char* arg_saved = cmdline;
char* arg;
struct kernel_option
{
const char* name;
bool has_parameter;
} options[] =
{
{ "--init", true },
};
size_t options_count = sizeof(options) / sizeof(options[0]);
while ( (arg = cmdline_tokenize(&arg_saved)) )
{
struct kernel_option* option = NULL;
char* parameter = NULL;
for ( size_t i = 0; i < options_count; i++ )
{
struct kernel_option* candidate = &options[i];
if ( candidate->has_parameter )
{
size_t name_length = strlen(candidate->name);
if ( strncmp(arg, candidate->name, name_length) != 0 )
continue;
if ( arg[name_length] == '=' )
parameter = arg + name_length + 1;
else if ( !arg[name_length] )
{
if ( !(parameter = cmdline_tokenize(&arg_saved)) )
{
Log::PrintF("\r\e[J");
Log::PrintF("kernel: fatal: option '%s' requires an argument\n", arg);
HaltKernel();
}
}
else
continue;
}
else if ( strcmp(arg, candidate->name) != 0 )
continue;
option = candidate;
}
if ( !option )
{
Log::PrintF("\r\e[J");
Log::PrintF("kernel: fatal: unrecognized option '%s'\n", arg);
HaltKernel();
}
if ( !strcmp(option->name, "--init") )
init_cmdline = parameter;
}
// Initialize the interrupt handler table and enable interrupts.
Interrupt::Init();
// Initialize the interrupt worker (before scheduling is enabled).
Interrupt::InitWorker();
//
// Stage 2. Transition to Multithreaded Environment
//
// Initialize the clocks.
Time::Init();
// Initialize Unix Signals.
Signal::Init();
// Now that the base system has been loaded, it's time to go threaded. First
// we create an object that represents this process.
Ref<ProcessTable> ptable(new ProcessTable());
if ( !ptable )
Panic("Could not allocate the process table");
Process* system = new Process;
if ( !system )
Panic("Could not allocate the system process");
if ( (system->pid = (system->ptable = ptable)->Allocate(system)) < 0 )
Panic("Could not allocate the system process a pid");
ptable.Reset();
system->addrspace = Memory::GetAddressSpace();
system->group = system;
system->groupprev = NULL;
system->groupnext = NULL;
system->groupfirst = system;
if ( !(system->program_image_path = String::Clone("<kernel process>")) )
Panic("Unable to clone string for system process name");
// We construct this thread manually for bootstrap reasons. We wish to
// create a kernel thread that is the current thread and isn't put into the
// scheduler's set of runnable threads, but rather run whenever there is
// _nothing_ else to run on this CPU.
Thread* idlethread = AllocateThread();
idlethread->process = system;
idlethread->kernelstackpos = (addr_t) stack;
idlethread->kernelstacksize = STACK_SIZE;
idlethread->kernelstackmalloced = false;
system->firstthread = idlethread;
Scheduler::SetIdleThread(idlethread);
// Let's create a regular kernel thread that can decide what happens next.
// Note that we don't do the work here: if all other threads are not running
// and this thread isn't runnable, then there is nothing to run. Therefore
// we must become the system idle thread.
RunKernelThread(BootThread, NULL);
// The time driver will run the scheduler on the next timer interrupt.
Time::Start();
// Become the system idle thread.
SystemIdleThread(NULL);
}
static void SystemIdleThread(void* /*user*/)
{
// Alright, we are now the system idle thread. If there is nothing to do,
// then we are run. Note that we must never do any real work here as the
// idle thread must always be runnable.
while(true);
}
static void BootThread(void* /*user*/)
{
//
// Stage 3. Spawning Kernel Worker Threads.
//
// Hello, threaded world! You can now regard the kernel as a multi-threaded
// process with super-root access to the system. Before we boot the full
// system we need to start some worker threads.
// Spawn worker threads to asyncronously draw the console thread.
TextBuffer* textbuf = Log::device_textbufhandle->Acquire();
if ( textbuf )
{
textbuf->SpawnThreads();
Log::device_textbufhandle->Release(textbuf);
}
// Let's create the interrupt worker thread that executes additional work
// requested by interrupt handlers, where such work isn't safe.
Thread* interruptworker = RunKernelThread(Interrupt::WorkerThread, NULL);
if ( !interruptworker )
Panic("Could not create interrupt worker");
// Initialize the worker thread data structures.
Worker::Init();
// Create a general purpose worker thread.
Thread* workerthread = RunKernelThread(Worker::Thread, NULL);
if ( !workerthread )
Panic("Unable to create general purpose worker thread");
//
// Stage 4. Initialize the Filesystem
//
// Bring up the filesystem cache.
FileCache::Init();
Ref<DescriptorTable> dtable(new DescriptorTable());
if ( !dtable )
Panic("Unable to allocate descriptor table");
Ref<MountTable> mtable(new MountTable());
if ( !mtable )
Panic("Unable to allocate mount table.");
CurrentProcess()->BootstrapTables(dtable, mtable);
// Let's begin preparing the filesystem.
// TODO: Setup the right device id for the KRAMFS dir?
Ref<Inode> iroot(new KRAMFS::Dir((dev_t) 0, (ino_t) 0, 0, 0, 0755));
if ( !iroot )
Panic("Unable to allocate root inode.");
ioctx_t ctx; SetupKernelIOCtx(&ctx);
Ref<Vnode> vroot(new Vnode(iroot, Ref<Vnode>(NULL), 0, 0));
if ( !vroot )
Panic("Unable to allocate root vnode.");
Ref<Descriptor> droot(new Descriptor(vroot, O_SEARCH));
if ( !droot )
Panic("Unable to allocate root descriptor.");
CurrentProcess()->BootstrapDirectories(droot);
// Initialize the root directory.
if ( iroot->link_raw(&ctx, ".", iroot) != 0 )
Panic("Unable to link /. to /");
if ( iroot->link_raw(&ctx, "..", iroot) != 0 )
Panic("Unable to link /.. to /");
// Extract the initrds.
if ( bootinfo->mods_count == 0 )
Panic("No initrd was loaded");
ExtractModules(bootinfo, droot);
//
// Stage 5. Loading and Initializing Core Drivers.
//
// Initialize the real-time clock.
CMOS::Init();
// Get a descriptor for the /dev directory so we can populate it.
if ( droot->mkdir(&ctx, "dev", 0775) != 0 && errno != EEXIST )
Panic("Unable to create RAM filesystem /dev directory.");
Ref<Descriptor> slashdev = droot->open(&ctx, "dev", O_READ | O_DIRECTORY);
if ( !slashdev )
Panic("Unable to create descriptor for RAM filesystem /dev directory.");
// Initialize the keyboard.
PS2Keyboard* keyboard = new PS2Keyboard();
if ( !keyboard )
Panic("Could not allocate PS2 Keyboard driver");
KeyboardLayoutExecutor* kblayout = new KeyboardLayoutExecutor;
if ( !kblayout )
Panic("Could not allocate keyboard layout executor");
if ( !kblayout->Upload(default_kblayout, sizeof(default_kblayout)) )
Panic("Could not load the default keyboard layout into the executor");
// Initialize the mouse.
PS2Mouse* mouse = new PS2Mouse();
if ( !mouse )
Panic("Could not allocate PS2 Mouse driver");
// Initialize the PS/2 controller.
PS2::Init(keyboard, mouse);
// Register the kernel terminal as /dev/tty.
Ref<Inode> tty(new LogTerminal(slashdev->dev, 0666, 0, 0, keyboard, kblayout));
if ( !tty )
Panic("Could not allocate a kernel terminal");
if ( LinkInodeInDir(&ctx, slashdev, "tty", tty) != 0 )
Panic("Unable to link /dev/tty to kernel terminal.");
// Register the mouse as /dev/mouse.
Ref<Inode> mousedev(new PS2MouseDevice(slashdev->dev, 0666, 0, 0, mouse));
if ( !mousedev )
Panic("Could not allocate a mouse device");
if ( LinkInodeInDir(&ctx, slashdev, "mouse", mousedev) != 0 )
Panic("Unable to link /dev/mouse to mouse.");
// Register the null device as /dev/null.
Ref<Inode> null_device(new Null(slashdev->dev, (ino_t) 0, (uid_t) 0,
(gid_t) 0, (mode_t) 0666));
if ( !null_device )
Panic("Could not allocate a null device");
if ( LinkInodeInDir(&ctx, slashdev, "null", null_device) != 0 )
Panic("Unable to link /dev/null to the null device.");
// Register the zero device as /dev/zero.
Ref<Inode> zero_device(new Zero(slashdev->dev, (ino_t) 0, (uid_t) 0,
(gid_t) 0, (mode_t) 0666));
if ( !zero_device )
Panic("Could not allocate a zero device");
if ( LinkInodeInDir(&ctx, slashdev, "zero", zero_device) != 0 )
Panic("Unable to link /dev/zero to the zero device.");
// Register the full device as /dev/full.
Ref<Inode> full_device(new Full(slashdev->dev, (ino_t) 0, (uid_t) 0,
(gid_t) 0, (mode_t) 0666));
if ( !full_device )
Panic("Could not allocate a full device");
if ( LinkInodeInDir(&ctx, slashdev, "full", full_device) != 0 )
Panic("Unable to link /dev/full to the full device.");
// Register the random device as /dev/random.
Ref<Inode> random_device(new DevRandom(slashdev->dev, (ino_t) 0, (uid_t) 0,
(gid_t) 0, (mode_t) 0666));
if ( !random_device )
Panic("Could not allocate a random device");
if ( LinkInodeInDir(&ctx, slashdev, "random", random_device) != 0 )
Panic("Unable to link /dev/random to the random device.");
if ( LinkInodeInDir(&ctx, slashdev, "urandom", random_device) != 0 )
Panic("Unable to link /dev/urandom to the random device.");
// Initialize the COM ports.
COM::Init("/dev", slashdev);
// Initialize the VGA driver.
VGA::Init("/dev", slashdev);
// Search for PCI devices and load their drivers.
PCI::Init();
// Initialize AHCI devices.
AHCI::Init("/dev", slashdev);
// Initialize ATA devices.
ATA::Init("/dev", slashdev);
// Initialize the BGA driver.
BGA::Init();
// Initialize the filesystem network-
NetFS::Init("/dev", slashdev);
//
// Stage 6. Executing Hosted Environment ("User-Space")
//
// Finally, let's transfer control to a new kernel process that will
// eventually run user-space code known as the operating system.
addr_t initaddrspace = Memory::Fork();
if ( !initaddrspace ) { Panic("Could not create init's address space"); }
Process* init = new Process;
if ( !init )
Panic("Could not allocate init process");
if ( (init->pid = (init->ptable = CurrentProcess()->ptable)->Allocate(init)) < 0 )
Panic("Could not allocate init a pid");
init->group = init;
init->groupprev = NULL;
init->groupnext = NULL;
init->groupfirst = init;
CurrentProcess()->AddChildProcess(init);
// TODO: Why don't we fork from pid=0 and this is done for us?
// TODO: Fork dtable and mtable, don't share them!
init->BootstrapTables(dtable, mtable);
dtable.Reset();
mtable.Reset();
init->BootstrapDirectories(droot);
init->addrspace = initaddrspace;
Scheduler::SetInitProcess(init);
Thread* initthread = RunKernelThread(init, InitThread, NULL);
if ( !initthread )
Panic("Could not create init thread");
// Wait until init init is done and then shut down the computer.
int status;
pid_t pid = CurrentProcess()->Wait(init->pid, &status, 0);
if ( pid != init->pid )
PanicF("Waiting for init to exit returned %ji (errno=%i)", (intmax_t) pid, errno);
status = WEXITSTATUS(status);
switch ( status )
{
case 0:
CPU::ShutDown();
case 1:
CPU::Reboot();
case 2:
Log::Print("kernel: fatal: Halting system due to init fatality\n");
Log::Sync();
HaltKernel();
default:
PanicF("Init returned with unexpected return code %i", status);
}
}
static void InitThread(void* /*user*/)
{
// We are the init process's first thread. Let's load the init program from
// the init ramdisk and transfer execution to it. We will then become a
// regular user-space program with root permissions.
Process* process = CurrentProcess();
ioctx_t ctx; SetupKernelIOCtx(&ctx);
Ref<Descriptor> root = CurrentProcess()->GetRoot();
Ref<DescriptorTable> dtable = process->GetDTable();
Ref<Descriptor> tty_stdin = root->open(&ctx, "/dev/tty", O_READ);
if ( !tty_stdin || dtable->Allocate(tty_stdin, 0) != 0 )
Panic("Could not prepare stdin for initialization process");
Ref<Descriptor> tty_stdout = root->open(&ctx, "/dev/tty", O_WRITE);
if ( !tty_stdout || dtable->Allocate(tty_stdout, 0) != 1 )
Panic("Could not prepare stdout for initialization process");
Ref<Descriptor> tty_stderr = root->open(&ctx, "/dev/tty", O_WRITE);
if ( !tty_stderr || dtable->Allocate(tty_stderr, 0) != 2 )
Panic("Could not prepare stderr for initialization process");
dtable.Reset();
static char default_init_cmdline[] = "/sbin/init";
if ( !init_cmdline )
init_cmdline = default_init_cmdline;
char* init_cmdline_dup = strdup(init_cmdline);
if ( !init_cmdline_dup )
PanicF("strdup: %m");
size_t init_cmdline_tokens = 0;
char* saved = init_cmdline_dup;
char* arg;
while ( (arg = cmdline_tokenize(&saved)) )
init_cmdline_tokens++;
free(init_cmdline_dup);
if ( INT_MAX - 1 < init_cmdline_tokens )
Panic("Too many tokens in init command line");
int argc = init_cmdline_tokens;
char** argv = new char*[argc + 1];
if ( !argv )
PanicF("operator new: %m");
saved = init_cmdline;
for ( int i = 0; i <= argc; i++ )
argv[i] = cmdline_tokenize(&saved);
if ( argc == 0 )
Panic("No init specified");
const char* initpath = argv[0];
Ref<Descriptor> init = root->open(&ctx, initpath, O_EXEC | O_READ);
if ( !init )
PanicF("Could not open %s in early kernel RAM filesystem:\n%s",
initpath, strerror(errno));
struct stat st;
if ( init->stat(&ctx, &st) )
PanicF("Could not stat '%s' in initrd.", initpath);
assert(0 <= st.st_size);
if ( (uintmax_t) SIZE_MAX < (uintmax_t) st.st_size )
PanicF("%s is bigger than SIZE_MAX.", initpath);
size_t programsize = st.st_size;
uint8_t* program = new uint8_t[programsize];
if ( !program )
PanicF("Unable to allocate 0x%zx bytes needed for %s.", programsize, initpath);
size_t sofar = 0;
while ( sofar < programsize )
{
ssize_t numbytes = init->read(&ctx, program+sofar, programsize-sofar);
if ( !numbytes )
PanicF("Premature EOF when reading %s.", initpath);
if ( numbytes < 0 )
PanicF("IO error when reading %s.", initpath);
sofar += numbytes;
}
init.Reset();
Log::PrintF("\r\e[m\e[J");
int envc = 0;
const char* envp[] = { NULL };
struct thread_registers regs;
assert((((uintptr_t) &regs) & (alignof(regs)-1)) == 0);
if ( process->Execute(initpath, program, programsize, argc, argv, envc,
envp, &regs) )
PanicF("Unable to execute %s.", initpath);
delete[] program;
delete[] argv;
// Now become the init process and the operation system shall run.
LoadRegisters(&regs);
}
} // namespace Sortix