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.

include/minix/com.h

@@ -73,6 +73,10 @@
 #define VM_PROC_NR        8     /* memory server */
 #define INIT_PROC_NR	  9    	/* init -- goes multiuser */
 
+/* Root system process and root user process. */
+#define ROOT_SYS_PROC_NR  RS_PROC_NR
+#define ROOT_USR_PROC_NR  INIT_PROC_NR
+
 /* Number of processes contained in the system image. */
 #define NR_BOOT_PROCS 	(NR_TASKS + INIT_PROC_NR + 1)
 
@@ -354,15 +358,15 @@
 #define SYS_ALL_CALLS (NR_SYS_CALLS)
 
 /* Subfunctions for SYS_PRIVCTL */
-#define SYS_PRIV_INIT		1	/* Initialize a privilege structure */
-#define SYS_PRIV_ADD_IO		2	/* Add I/O range (struct io_range) */
-#define SYS_PRIV_ADD_MEM	3	/* Add memory range (struct mem_range)
+#define SYS_PRIV_ALLOW		1	/* Allow process to run */
+#define SYS_PRIV_DISALLOW	2	/* Disallow process to run */
+#define SYS_PRIV_SET_SYS	3	/* Set a system privilege structure */
+#define SYS_PRIV_SET_USER	4	/* Set a user privilege structure */
+#define SYS_PRIV_ADD_IO 	5	/* Add I/O range (struct io_range) */
+#define SYS_PRIV_ADD_MEM	6	/* Add memory range (struct mem_range)
 					 */
-#define SYS_PRIV_ADD_IRQ	4	/* Add IRQ */
-#define SYS_PRIV_USER		5	/* Make a process an oridinary user 
-					 * process.
-					 */
-#define SYS_PRIV_QUERY_MEM	6	/* Verify memory privilege. */
+#define SYS_PRIV_ADD_IRQ	7	/* Add IRQ */
+#define SYS_PRIV_QUERY_MEM	8	/* Verify memory privilege. */
 
 /* Subfunctions for SYS_SETGRANT */
 #define SYS_PARAM_SET_GRANT	1	/* Set address and size of grant table */
@@ -478,11 +482,12 @@
 #   define GET_BIOSBUFFER 14	/* get a buffer for BIOS calls */
 #   define GET_LOADINFO   15	/* get load average information */
 #   define GET_IRQACTIDS  16	/* get the IRQ masks */
-#   define GET_PRIVID	  17	/* get ID of privilege structure */
+#   define GET_PRIV	  17	/* get privilege structure */
 #   define GET_HZ	  18	/* get HZ value */
 #   define GET_WHOAMI	  19	/* get own name and endpoint */
 #   define GET_RANDOMNESS_BIN 20 /* get one randomness bin */
 #   define GET_IDLETSC	  21	/* get cumulative idle time stamp counter */
+#   define GET_AOUTHEADER     22 /* get a.out headers from the boot image */
 #define I_ENDPT      m7_i4	/* calling process */
 #define I_VAL_PTR      m7_p1	/* virtual address at caller */ 
 #define I_VAL_LEN      m7_i1	/* max length of value */

include/minix/const.h

@@ -132,12 +132,14 @@
 #define SERVARNAME		"cttyline"
 
 /* Bits for the system property flags in boot image processes. */
+#define PROC_FULLVM    0x100    /* VM sets and manages full pagetable */
+
+/* Bits for s_flags in the privilege structure. */
 #define PREEMPTIBLE     0x02    /* kernel tasks are not preemptible */
 #define BILLABLE        0x04    /* some processes are not billable */
+#define DYN_PRIV_ID     0x08    /* privilege id assigned dynamically */
  
 #define SYS_PROC        0x10    /* system processes have own priv structure */
 #define CHECK_IO_PORT   0x20    /* check if I/O request is allowed */
 #define CHECK_IRQ       0x40    /* check if IRQ can be used */
 #define CHECK_MEM       0x80    /* check if (VM) mem map request is allowed */
-#define PROC_FULLVM    0x100    /* VM sets and manages full pagetable */
-

include/minix/syslib.h

@@ -101,7 +101,7 @@ _PROTOTYPE(void *alloc_contig, (size_t len, int flags, phys_bytes *phys));
  * retrieve/set a process-virtual timer.
  */
 _PROTOTYPE( int sys_times, (endpoint_t proc_ep, clock_t *user_time,
-	clock_t *sys_time, clock_t *uptime));
+	clock_t *sys_time, clock_t *uptime, time_t *boottime));
 _PROTOTYPE(int sys_setalarm, (clock_t exp_time, int abs_time));
 _PROTOTYPE( int sys_vtimer, (endpoint_t proc_nr, int which, clock_t *newval,
 	clock_t *oldval));
@@ -178,8 +178,9 @@ _PROTOTYPE(int sys_segctl, (int *index, u16_t *seg, vir_bytes *off,
 #define sys_getmonparams(v,vl)	sys_getinfo(GET_MONPARAMS, v,vl, 0,0)
 #define sys_getschedinfo(v1,v2)	sys_getinfo(GET_SCHEDINFO, v1,0, v2,0)
 #define sys_getlocktimings(dst)	sys_getinfo(GET_LOCKTIMING, dst, 0,0,0)
-#define sys_getprivid(nr)	sys_getinfo(GET_PRIVID, 0, 0,0, nr)
+#define sys_getpriv(dst, nr)	sys_getinfo(GET_PRIV, dst, 0,0, nr)
 #define sys_getidletsc(dst)	sys_getinfo(GET_IDLETSC, dst, 0,0,0)
+#define sys_getaoutheader(dst,nr) sys_getinfo(GET_AOUTHEADER, dst, 0,0,nr)
 _PROTOTYPE(int sys_getinfo, (int request, void *val_ptr, int val_len,
 				 void *val_ptr2, int val_len2)		);
 _PROTOTYPE(int sys_whoami, (endpoint_t *ep, char *name, int namelen));