initial checkout from wrc

1 files changed, 112 insertions, 0 deletions

diff --git a/lib/klibc.c b/lib/klibc.c
new file mode 100644
index 0000000..ded0c78
--- /dev/null
+++ b/lib/klibc.c
@@ -0,0 +1,112 @@
+/*
+** @file klibc.c
+**
+** @author  Warren R. Carithers
+**
+** Additional support functions for the kernel.
+**
+*/
+
+#define KERNEL_SRC
+
+#include <klib.h>
+#include <cio.h>
+#include <procs.h>
+#include <support.h>
+
+/**
+** Name:    put_char_or_code( ch )
+**
+** Description: Prints a character on the console, unless it
+** is a non-printing character, in which case its hex code
+** is printed
+**
+** @param ch    The character to be printed
+*/
+void put_char_or_code( int ch ) {
+
+	if( ch >= ' ' && ch < 0x7f ) {
+		cio_putchar( ch );
+	} else {
+		cio_printf( "\\x%02x", ch );
+	}
+}
+
+/**
+** Name:    backtrace
+**
+** Perform a stack backtrace
+**
+** @param ebp   Initial EBP to use
+** @param args  Number of function argument values to print
+*/
+void backtrace( uint32_t *ebp, uint_t args ) {
+
+	cio_puts( "Trace:  " );
+	if( ebp == NULL ) {
+		cio_puts( "NULL ebp, no trace possible\n" );
+		return;
+	} else {
+		cio_putchar( '\n' );
+	}
+
+	while( ebp != NULL ){
+
+		// get return address and report it and EBP
+		uint32_t ret = ebp[1];
+		cio_printf( " ebp %08x ret %08x args", (uint32_t) ebp, ret );
+
+		// print the requested number of function arguments
+		for( uint_t i = 0; i < args; ++i ) {
+			cio_printf( " [%u] %08x", i+1, ebp[2+i] );
+		}
+		cio_putchar( '\n' );
+
+		// follow the chain
+		ebp = (uint32_t *) *ebp;
+	}
+}
+
+/**
+** kpanic - kernel-level panic routine
+**
+** usage:  kpanic( msg )
+**
+** Prefix routine for panic() - can be expanded to do other things
+** (e.g., printing a stack traceback)
+**
+** @param msg[in]  String containing a relevant message to be printed,
+**				   or NULL
+*/
+void kpanic( const char *msg ) {
+
+	cio_puts( "\n\n***** KERNEL PANIC *****\n\n" );
+
+	if( msg ) {
+		cio_printf( "%s\n", msg );
+	}
+
+	delay( DELAY_5_SEC );   // approximately
+
+	// dump a bunch of potentially useful information
+
+	// dump the contents of the current PCB
+	pcb_dump( "Current", current, true );
+
+	// dump the basic info about what's in the process table
+	ptable_dump_counts();
+
+	// dump information about the queues
+	pcb_queue_dump( "R", ready, true );
+	pcb_queue_dump( "W", waiting, true );
+	pcb_queue_dump( "S", sleeping, true );
+	pcb_queue_dump( "Z", zombie, true );
+	pcb_queue_dump( "I", sioread, true );
+
+	// perform a stack backtrace
+	backtrace( (uint32_t *) r_ebp(), 3 );
+
+	// could dump other stuff here, too
+
+	panic( "KERNEL PANIC" );
+}