make panic() work for multiboot/elf case

. we cannot use the boot monitor to print the system diag buffer
	. for serial, we do nothing, just reset, everything is already printed
	. for not-serial, we print the current diag buffer using direct video
	  memory access from the kernel

kernel/arch/i386/arch_system.c

@@ -25,6 +25,7 @@
 #include "oxpcie.h"
 #include "kernel/proc.h"
 #include "kernel/debug.h"
+#include "mb_utils.h"
 #include <machine/multiboot.h>
 
 #include "glo.h"
@@ -85,15 +86,14 @@ PUBLIC int cpu_has_tsc;
 
 PUBLIC __dead void arch_shutdown(int how)
 {
-	static char mybuffer[sizeof(params_buffer)];
 	u16_t magic;
 	vm_stop();
 
 	/* Mask all interrupts, including the clock. */
 	outb( INT_CTLMASK, ~0);
 
-#if USE_BOOTPARAM
 	if(minix_panicing) {
+		unsigned char unused_ch;
 		/* We're panicing? Then retrieve and decode currently
 		 * loaded segment selectors.
 		 */
@@ -102,8 +102,22 @@ PUBLIC __dead void arch_shutdown(int how)
 		if(read_ds() != read_ss()) {
 			printseg("ss: ", 0, NULL, read_ss());
 		}
+
+		/* Printing is done synchronously over serial. */
+		if (do_serial_debug)
+			reset();
+
+		/* Print accumulated diagnostics buffer and reset. */
+		mb_cls();
+		mb_print("Minix panic. System diagnostics buffer:\n\n");
+		mb_print(kmess_buf);
+		mb_print("\nSystem has panicked, press any key to reboot");
+		while (!mb_read_char(&unused_ch))
+			;
+		reset();
 	}
 
+#if USE_BOOTPARAM
 	if (how == RBT_DEFAULT) {
 		how = mon_return ? RBT_HALT : RBT_RESET;
 	}
@@ -119,37 +133,7 @@ PUBLIC __dead void arch_shutdown(int how)
 		 */
 		if (how != RBT_MONITOR)
 			arch_set_params("", 1);
-		if(minix_panicing) {
-			int source, dest;
-			const char *lead = "echo \\n*** kernel messages:\\n";
-			const int leadlen = strlen(lead);
-			strcpy(mybuffer, lead);
 
-#define DECSOURCE source = (source - 1 + _KMESS_BUF_SIZE) % _KMESS_BUF_SIZE
-
-			dest = sizeof(mybuffer)-1;
-			mybuffer[dest--] = '\0';
-
-			source = kmess.km_next;
-			DECSOURCE; 
-
-			while(dest >= leadlen) {
-				const char c = kmess.km_buf[source];
-				if(c == '\n') {
-					mybuffer[dest--] = 'n';
-					mybuffer[dest] = '\\';
-				} else if(isprint(c) &&
-					c != '\'' && c != '"' &&
-					c != '\\' && c != ';') {
-					mybuffer[dest] = c;
-				} else	mybuffer[dest] = ' ';
-
-				DECSOURCE;
-				dest--;
-			}
-
-			arch_set_params(mybuffer, strlen(mybuffer)+1);
-		}
 		if (mon_return)
 			arch_monitor();
 
@@ -157,14 +141,7 @@ PUBLIC __dead void arch_shutdown(int how)
 		 * depending on the parameters
 		 */
 		if (how == RBT_MONITOR) {
-			mybuffer[0] = '\0';
-			arch_get_params(mybuffer, sizeof(mybuffer));
-			if (strstr(mybuffer, "boot") ||
-				strstr(mybuffer, "menu") ||	
-				strstr(mybuffer, "reset"))
-				how = RBT_RESET;
-			else
-				how = RBT_HALT;
+			how = RBT_RESET;
 		}
 	}
 
@@ -643,8 +620,6 @@ PUBLIC void arch_ack_profile_clock(void)
 
 #endif
 
-#define COLOR_BASE	0xB8000L
-
 /* Saved by mpx386.s into these variables. */
 u32_t params_size, params_offset, mon_ds;
 

kernel/arch/i386/mb_utils.h

@@ -0,0 +1,12 @@
+#ifndef MB_UTILS_H
+#define MB_UTILS_H
+
+#include "kernel/kernel.h"
+
+_PROTOTYPE(void mb_cls, (void));
+_PROTOTYPE(void mb_print, (char*));
+_PROTOTYPE(void mb_print_char, (char));
+_PROTOTYPE(int mb_read_char, (unsigned char*));
+
+
+#endif

kernel/arch/i386/pre_init.c

@@ -16,6 +16,8 @@
 #include "string.h"
 #include "arch_proto.h"
 #include "libexec.h"
+#include "mb_utils.h"
+#include "serial.h"
 #include <machine/multiboot.h>
 
 #if USE_SYSDEBUG
@@ -38,8 +40,6 @@
 #define mb_save_phymem(buf, phy, len) \
 		phys_copy((u32_t)(buf), (phy), (len))
 
-FORWARD _PROTOTYPE(void mb_print, (char *str));
-
 PRIVATE void mb_itoa(u32_t val, char * out) 
 {
 	char ret[ITOA_BUFFER_SIZE];
@@ -117,50 +117,104 @@ PRIVATE char mb_get_char(int line, int col)
 
 /* Give non-zero values to avoid them in BSS */
 PRIVATE int print_line = 1, print_col = 1;
+
+#include <sys/video.h>
 	
-PRIVATE void mb_cls(void) 
+PUBLIC void mb_cls(void)
 {
-#if MULTIBOOT_VERBOSE
 	int i, j;
 	/* Clear screen */
 	for (i = 0; i < MULTIBOOT_CONSOLE_LINES; i++ )
 		for (j = 0; j < MULTIBOOT_CONSOLE_COLS; j++ )
 			mb_put_char(0, i, j);
 	print_line = print_col = 0;
-#endif
+
+	/* Tell video hardware origin is 0. */
+	outb(C_6845+INDEX, VID_ORG);
+	outb(C_6845+DATA, 0);
+	outb(C_6845+INDEX, VID_ORG+1);
+	outb(C_6845+DATA, 0);
 }
 
 PRIVATE void mb_scroll_up(int lines) 
 {
 	int i, j;
-	for (i = 0; i < MULTIBOOT_CONSOLE_LINES - lines; i++ ) {
-		for (j = 0; j < MULTIBOOT_CONSOLE_COLS; j++ )
-			mb_put_char(mb_get_char(i + lines, j), i, j);
+	for (i = 0; i < MULTIBOOT_CONSOLE_LINES; i++ ) {
+		for (j = 0; j < MULTIBOOT_CONSOLE_COLS; j++ ) {
+			char c = 0;
+			if(i < MULTIBOOT_CONSOLE_LINES-lines)
+				c = mb_get_char(i + lines, j);
+			mb_put_char(c, i, j);
+		}
 	}
 	print_line-= lines;
 }
 
-PRIVATE void mb_print(char *str) 
+PUBLIC void mb_print_char(char c)
 {
-#if MULTIBOOT_VERBOSE
-	while (*str) {
-		if (*str == '\n') {
-			str++;
-			while (print_col < MULTIBOOT_CONSOLE_COLS)
-				mb_put_char(' ', print_line, print_col++);
-			print_line++;
-			print_col = 0;
-			continue;
-		}
-		mb_put_char(*str++, print_line, print_col++);
-		if (print_col >= MULTIBOOT_CONSOLE_COLS) {
-			print_line++;
-			print_col = 0;
-		}
-		while (print_line >= MULTIBOOT_CONSOLE_LINES)
-			mb_scroll_up(1);
+	while (print_line >= MULTIBOOT_CONSOLE_LINES)
+		mb_scroll_up(1);
+
+	if (c == '\n') {
+		while (print_col < MULTIBOOT_CONSOLE_COLS)
+			mb_put_char(' ', print_line, print_col++);
+		print_line++;
+		print_col = 0;
+		return;
 	}
-#endif /* MULTIBOOT_VERBOSE */
+
+	mb_put_char(c, print_line, print_col++);
+
+	if (print_col >= MULTIBOOT_CONSOLE_COLS) {
+		print_line++;
+		print_col = 0;
+	}
+
+	while (print_line >= MULTIBOOT_CONSOLE_LINES)
+		mb_scroll_up(1);
+}
+
+PUBLIC void mb_print(char *str)
+{
+	while (*str) {
+		mb_print_char(*str);
+		str++;
+	}
+}
+
+/* Standard and AT keyboard.  (PS/2 MCA implies AT throughout.) */
+#define KEYBD		0x60	/* I/O port for keyboard data */
+#define KB_STATUS	0x64	/* I/O port for status on AT */
+#define KB_OUT_FULL	0x01	/* status bit set when keypress char pending */
+#define KB_AUX_BYTE	0x20	/* Auxiliary Device Output Buffer Full */
+
+PUBLIC int mb_read_char(unsigned char *ch)
+{
+	unsigned long b, sb;
+#ifdef DEBUG_SERIAL
+	u8_t c, lsr;
+
+	if (do_serial_debug) {
+		lsr= inb(COM1_LSR);
+		if (!(lsr & LSR_DR))
+			return 0;
+		c = inb(COM1_RBR);
+		return 1;
+	}
+#endif /* DEBUG_SERIAL */
+
+	sb = inb(KB_STATUS);
+
+	if (!(sb & KB_OUT_FULL)) {
+		return 0;
+	}
+
+	b = inb(KEYBD);
+
+	if (!(sb & KB_AUX_BYTE))
+		return 1;
+
+	return 0;
 }
 
 PRIVATE void mb_print_hex(u32_t value) 

kernel/glo.h

@@ -22,6 +22,7 @@
 EXTERN struct kinfo kinfo;		/* kernel information for users */
 EXTERN struct machine machine;		/* machine information for users */
 EXTERN struct kmessages kmess;  	/* diagnostic messages in kernel */
+EXTERN char kmess_buf[80*25];		/* printable copy of message buffer */
 EXTERN struct k_randomness krandom;	/* gather kernel random information */
 EXTERN struct loadinfo kloadinfo;	/* status of load average */
 

kernel/utility.c

@@ -23,7 +23,7 @@ PUBLIC void panic(const char *fmt, ...)
   va_list arg;
   /* The system has run aground of a fatal kernel error. Terminate execution. */
   if (minix_panicing == ARE_PANICING) {
-	arch_monitor();
+  	reset();
   }
   minix_panicing = ARE_PANICING;
   if (fmt != NULL) {
@@ -53,6 +53,8 @@ int c;					/* character to append */
  * to the output driver if an END_OF_KMESS is encountered. 
  */
   if (c != END_OF_KMESS) {
+      static int blpos = 0;
+      int maxblpos = sizeof(kmess_buf) - 2;
 #ifdef DEBUG_SERIAL
       if (do_serial_debug) {
 	if(c == '\n')
@@ -61,9 +63,13 @@ int c;					/* character to append */
       }
 #endif
       kmess.km_buf[kmess.km_next] = c;	/* put normal char in buffer */
+      kmess_buf[blpos] = c;
       if (kmess.km_size < sizeof(kmess.km_buf))
           kmess.km_size += 1;		
       kmess.km_next = (kmess.km_next + 1) % _KMESS_BUF_SIZE;
+      if(blpos == maxblpos) {
+      	memmove(kmess_buf, kmess_buf+1, sizeof(kmess_buf)-1);
+      } else blpos++;
   } else {
       int p;
       endpoint_t outprocs[] = OUTPUT_PROCS_ARRAY;