minix/kernel/table.c
Tomas Hruby 728f0f0c49 Removal of the system task
* Userspace change to use the new kernel calls

	- _taskcall(SYSTASK...) changed to _kernel_call(...)

	- int 32 reused for the kernel calls

	- _do_kernel_call() to make the trap to kernel

	- kernel_call() to make the actuall kernel call from C using
	  _do_kernel_call()

	- unlike ipc call the kernel call always succeeds as kernel is
	  always available, however, kernel may return an error

* Kernel side implementation of kernel calls

	- the SYSTEm task does not run, only the proc table entry is
	  preserved

	- every data_copy(SYSTEM is no data_copy(KERNEL

	- "locking" is an empty operation now as everything runs in
	  kernel

	- sys_task() is replaced by kernel_call() which copies the
	  message into kernel, dispatches the call to its handler and
	  finishes by either copying the results back to userspace (if
	  need be) or by suspending the process because of VM

	- suspended processes are later made runnable once the memory
	  issue is resolved, picked up by the scheduler and only at
	  this time the call is resumed (in fact restarted) which does
	  not need to copy the message from userspace as the message
	  is already saved in the process structure.

	- no ned for the vmrestart queue, the scheduler will restart
	  the system calls

	- no special case in do_vmctl(), all requests remove the
	  RTS_VMREQUEST flag
2010-02-09 15:20:09 +00:00

91 lines
4.0 KiB
C

/* The object file of "table.c" contains most kernel data. Variables that
* are declared in the *.h files appear with EXTERN in front of them, as in
*
* EXTERN int x;
*
* Normally EXTERN is defined as extern, so when they are included in another
* file, no storage is allocated. If EXTERN were not present, but just say,
*
* int x;
*
* then including this file in several source files would cause 'x' to be
* declared several times. While some linkers accept this, others do not,
* so they are declared extern when included normally. However, it must be
* declared for real somewhere. That is done here, by redefining EXTERN as
* the null string, so that inclusion of all *.h files in table.c actually
* generates storage for them.
*
* Various variables could not be declared EXTERN, but are declared PUBLIC
* or PRIVATE. The reason for this is that extern variables cannot have a
* default initialization. If such variables are shared, they must also be
* declared in one of the *.h files without the initialization. Examples
* include 'boot_image' (this file) and 'idt' and 'gdt' (protect.c).
*
* Changes:
* Nov 22, 2009 rewrite of privilege management (Cristiano Giuffrida)
* Aug 02, 2005 set privileges and minimal boot image (Jorrit N. Herder)
* Oct 17, 2004 updated above and tasktab comments (Jorrit N. Herder)
* May 01, 2004 changed struct for system image (Jorrit N. Herder)
*/
#define _TABLE
#include "kernel.h"
#include "proc.h"
#include "ipc.h"
#include <minix/com.h>
/* Define stack sizes for the kernel tasks included in the system image. */
#define NO_STACK 0
#define SMALL_STACK (1024 * sizeof(char *))
#define IDL_S SMALL_STACK /* 3 intr, 3 temps, 4 db for Intel */
#define HRD_S NO_STACK /* dummy task, uses kernel stack */
#define TSK_S SMALL_STACK /* system and clock task */
/* Stack space for all the task stacks. Declared as (char *) to align it. */
#define TOT_STACK_SPACE (IDL_S + HRD_S + (2 * TSK_S))
PUBLIC char *t_stack[TOT_STACK_SPACE / sizeof(char *)];
/* Define boot process flags. */
#define BVM_F (PROC_FULLVM) /* boot processes with VM */
/* The system image table lists all programs that are part of the boot image.
* The order of the entries here MUST agree with the order of the programs
* in the boot image and all kernel tasks must come first.
*
* Each entry provides the process number, flags, quantum size, scheduling
* queue, and a name for the process table. The initial program counter and
* stack size is also provided for kernel tasks.
*
* Note: the quantum size must be positive in all cases!
*/
PUBLIC struct boot_image image[] = {
/* process nr, pc, flags, qs, queue, stack, name */
{IDLE, NULL, 0, 0, 0, IDL_S, "idle" },
{CLOCK,clock_task, 0, 8, TASK_Q, TSK_S, "clock" },
{SYSTEM, NULL, 0, 0, 0, IDL_S, "system"},
{HARDWARE, 0, 0, 8, TASK_Q, HRD_S, "kernel"},
{PM_PROC_NR, 0, 0, 32, 4, 0, "pm" },
{FS_PROC_NR, 0, 0, 32, 5, 0, "vfs" },
{RS_PROC_NR, 0, 0, 4, 4, 0, "rs" },
{MEM_PROC_NR, 0, BVM_F, 4, 3, 0, "memory"},
{LOG_PROC_NR, 0, BVM_F, 4, 2, 0, "log" },
{TTY_PROC_NR, 0, BVM_F, 4, 1, 0, "tty" },
{DS_PROC_NR, 0, BVM_F, 4, 4, 0, "ds" },
{MFS_PROC_NR, 0, BVM_F, 32, 5, 0, "mfs" },
{VM_PROC_NR, 0, 0, 32, 2, 0, "vm" },
{PFS_PROC_NR, 0, BVM_F, 32, 5, 0, "pfs" },
{INIT_PROC_NR, 0, BVM_F, 8, USER_Q, 0, "init" },
};
/* Verify the size of the system image table at compile time. Also verify that
* the first chunk of the ipc mask has enough bits to accommodate the processes
* in the image.
* If a problem is detected, the size of the 'dummy' array will be negative,
* causing a compile time error. Note that no space is actually allocated
* because 'dummy' is declared extern.
*/
extern int dummy[(NR_BOOT_PROCS==sizeof(image)/
sizeof(struct boot_image))?1:-1];
extern int dummy[(BITCHUNK_BITS > NR_BOOT_PROCS - 1) ? 1 : -1];