minix/servers/rs/glo.h

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Rewrite of boot process KERNEL CHANGES: - The kernel only knows about privileges of kernel tasks and the root system process (now RS). - Kernel tasks and the root system process are the only processes that are made schedulable by the kernel at startup. All the other processes in the boot image don't get their privileges set at startup and are inhibited from running by the RTS_NO_PRIV flag. - Removed the assumption on the ordering of processes in the boot image table. System processes can now appear in any order in the boot image table. - Privilege ids can now be assigned both statically or dynamically. The kernel assigns static privilege ids to kernel tasks and the root system process. Each id is directly derived from the process number. - User processes now all share the static privilege id of the root user process (now INIT). - sys_privctl split: we have more calls now to let RS set privileges for system processes. SYS_PRIV_ALLOW / SYS_PRIV_DISALLOW are only used to flip the RTS_NO_PRIV flag and allow / disallow a process from running. SYS_PRIV_SET_SYS / SYS_PRIV_SET_USER are used to set privileges for a system / user process. - boot image table flags split: PROC_FULLVM is the only flag that has been moved out of the privilege flags and is still maintained in the boot image table. All the other privilege flags are out of the kernel now. RS CHANGES: - RS is the only user-space process who gets to run right after in-kernel startup. - RS uses the boot image table from the kernel and three additional boot image info table (priv table, sys table, dev table) to complete the initialization of the system. - RS checks that the entries in the priv table match the entries in the boot image table to make sure that every process in the boot image gets schedulable. - RS only uses static privilege ids to set privileges for system services in the boot image. - RS includes basic memory management support to allocate the boot image buffer dynamically during initialization. The buffer shall contain the executable image of all the system services we would like to restart after a crash. - First step towards decoupling between resource provisioning and resource requirements in RS: RS must know what resources it needs to restart a process and what resources it has currently available. This is useful to tradeoff reliability and resource consumption. When required resources are missing, the process cannot be restarted. In that case, in the future, a system flag will tell RS what to do. For example, if CORE_PROC is set, RS should trigger a system-wide panic because the system can no longer function correctly without a core system process. PM CHANGES: - The process tree built at initialization time is changed to have INIT as root with pid 0, RS child of INIT and all the system services children of RS. This is required to make RS in control of all the system services. - PM no longer registers labels for system services in the boot image. This is now part of RS's initialization process.
2009-12-11 01:08:19 +01:00
/* Global variables used in RS.
*/
#ifndef RS_GLO_H
#define RS_GLO_H
#ifdef _TABLE
#undef EXTERN
#define EXTERN
#endif
/* The boot image priv table. This table has entries for all system
* services in the boot image.
*/
extern struct boot_image_priv boot_image_priv_table[];
/* The boot image sys table. This table has entries for system services in
* the boot image that override default sys properties.
*/
extern struct boot_image_sys boot_image_sys_table[];
/* The boot image dev table. This table has entries for system services in
* the boot image that support dev properties.
*/
extern struct boot_image_dev boot_image_dev_table[];
/* The system process table. This table only has entries for system
* services (servers and drivers), and thus is not directly indexed by
* slot number.
*/
EXTERN struct rproc rproc[NR_SYS_PROCS];
EXTERN struct rproc *rproc_ptr[NR_PROCS]; /* mapping for fast access */
/* Pipe for detection of exec failures. The pipe is close-on-exec, and
* no data will be written to the pipe if the exec succeeds. After an
* exec failure, the slot number is written to the pipe. After each exit,
* a non-blocking read retrieves the slot number from the pipe.
*/
EXTERN int exec_pipe[2];
/* Enable/disable verbose output. */
EXTERN long rs_verbose;
#endif /* RS_GLO_H */