Added errno, strerror and the "%m" printf metacharacter. These will allow

us to return proper PXE status codes, while simultaneously allowing for
more consistent error reporting (complete with verbose error messages as a
build-time option).

src/core/errno.c

@@ -0,0 +1,29 @@
+#include "errno.h"
+#include "vsprintf.h"
+
+/* Global "last error" number */
+int errno;
+
+static struct errortab errortab_start[0] __table_start(errortab);
+static struct errortab errortab_end[0] __table_end(errortab);
+
+/*
+ * Retrieve string representation of error number.
+ *
+ * If error not found in the error table, generate a generic "Error
+ * 0x0000" message.
+ *
+ */
+const char * strerror ( int errno ) {
+	static char *generic_message = "Error 0x0000";
+	struct errortab *errortab;
+
+	for ( errortab = errortab_start ; errortab < errortab_end ;
+	      errortab++ ) {
+		if ( errortab->errno == errno )
+			return errortab->text;
+	}
+
+	sprintf ( generic_message + 8, "%hx", errno );
+	return generic_message;
+}

src/core/vsprintf.c

@@ -2,6 +2,7 @@
 #include "if_ether.h" /* for ETH_ALEN */
 #include "limits.h" /* for CHAR_BIT */
 #include "console.h"
+#include "errno.h"
 #include "vsprintf.h"
 
 #define LONG_SHIFT  ((int)((sizeof(unsigned long)*CHAR_BIT) - 4))
@@ -31,7 +32,8 @@ PRINTF and friends
 **************************************************************************/
 static int vsprintf(char *buf, const char *fmt, va_list args)
 {
-	char *p, *s;
+	const char *p;
+	char *s;
 	s = buf;
 	for ( ; *fmt != '\0'; ++fmt) {
 		if (*fmt != '%') {
@@ -49,8 +51,10 @@ static int vsprintf(char *buf, const char *fmt, va_list args)
 		if (*fmt == 's') {
 			for(p = va_arg(args, char *); *p != '\0'; p++) 
 				buf ? *s++ = *p : putchar(*p);
-		}
-		else {	/* Length of item is bounded */
+		} else if (*fmt == 'm') {
+			for(p = strerror(errno); *p != '\0'; p++)
+				buf ? *s++ = *p : putchar(*p);
+		} else {	/* Length of item is bounded */
 			char tmp[40], *q = tmp;
 			int alt = 0;
 			int shift = INT_SHIFT;
@@ -93,7 +97,7 @@ static int vsprintf(char *buf, const char *fmt, va_list args)
 					*q++ = "0123456789ABCDEF"[(h >> shift) & 0xF] | ncase;
 			}
 			else if (*fmt == 'd') {
-				char *r;
+				char *r, *t;
 				long i;
 				if (shift > INT_SHIFT) {
 					i = va_arg(args, long);
@@ -104,17 +108,17 @@ static int vsprintf(char *buf, const char *fmt, va_list args)
 					*q++ = '-';
 					i = -i;
 				}
-				p = q;		/* save beginning of digits */
+				t = q;		/* save beginning of digits */
 				do {
 					*q++ = '0' + (i % 10);
 					i /= 10;
 				} while (i);
 				/* reverse digits, stop in middle */
 				r = q;		/* don't alter q */
-				while (--r > p) {
+				while (--r > t) {
 					i = *r;
-					*r = *p;
-					*p++ = i;
+					*r = *t;
+					*t++ = i;
 				}
 			}
 			else if (*fmt == '@') {
@@ -129,7 +133,7 @@ static int vsprintf(char *buf, const char *fmt, va_list args)
 				--q;
 			}
 			else if (*fmt == '!') {
-				char *r;
+				const char *r;
 				p = va_arg(args, char *);
 				for (r = p + ETH_ALEN; p < r; ++p)
 					q += sprintf(q, "%hhX:", *p);

src/include/errno.h

@@ -0,0 +1,138 @@
+#ifndef ERRNO_H
+#define ERRNO_H
+
+/*
+ * We define error codes that are a superset of those mentioned in the
+ * PXE specification.  Various error string tables may be compiled in
+ * if required; if not compiled in, strerror(errno) will produce the
+ * text "error 0x<errno>".
+ *
+ */
+
+/* PXE error codes are determined by the PXE specification */
+
+/* Generic errors */
+#define	PXENV_STATUS_SUCCESS				0x00
+#define	PXENV_STATUS_FAILURE				0x01
+#define	PXENV_STATUS_BAD_FUNC				0x02
+#define	PXENV_STATUS_UNSUPPORTED			0x03
+#define	PXENV_STATUS_KEEP_UNDI				0x04
+#define	PXENV_STATUS_KEEP_ALL				0x05
+#define	PXENV_STATUS_OUT_OF_RESOURCES			0x06
+
+/* ARP errors (0x10 to 0x1f) */
+#define	PXENV_STATUS_ARP_TIMEOUT			0x11
+
+/* Base-Code state errors */
+#define	PXENV_STATUS_UDP_CLOSED				0x18
+#define	PXENV_STATUS_UDP_OPEN				0x19
+#define	PXENV_STATUS_TFTP_CLOSED			0x1a
+#define	PXENV_STATUS_TFTP_OPEN				0x1b
+
+/* BIOS/system errors (0x20 to 0x2f) */
+#define	PXENV_STATUS_MCOPY_PROBLEM			0x20
+#define	PXENV_STATUS_BIS_INTEGRITY_FAILURE		0x21
+#define	PXENV_STATUS_BIS_VALIDATE_FAILURE		0x22
+#define	PXENV_STATUS_BIS_INIT_FAILURE			0x23
+#define	PXENV_STATUS_BIS_SHUTDOWN_FAILURE		0x24
+#define	PXENV_STATUS_BIS_GBOA_FAILURE			0x25
+#define	PXENV_STATUS_BIS_FREE_FAILURE			0x26
+#define	PXENV_STATUS_BIS_GSI_FAILURE			0x27
+#define	PXENV_STATUS_BIS_BAD_CKSUM			0x28
+
+/* TFTP/MTFTP errors (0x30 to 0x3f) */
+#define	PXENV_STATUS_TFTP_CANNOT_ARP_ADDRESS		0x30
+#define	PXENV_STATUS_TFTP_OPEN_TIMEOUT			0x32
+#define	PXENV_STATUS_TFTP_UNKNOWN_OPCODE		0x33
+#define	PXENV_STATUS_TFTP_READ_TIMEOUT			0x35
+#define	PXENV_STATUS_TFTP_ERROR_OPCODE			0x36
+#define	PXENV_STATUS_TFTP_CANNOT_OPEN_CONNECTION	0x38
+#define	PXENV_STATUS_TFTP_CANNOT_READ_FROM_CONNECTION	0x39
+#define	PXENV_STATUS_TFTP_TOO_MANY_PACKAGES		0x3a
+#define	PXENV_STATUS_TFTP_FILE_NOT_FOUND		0x3b
+#define	PXENV_STATUS_TFTP_ACCESS_VIOLATION		0x3c
+#define	PXENV_STATUS_TFTP_NO_MCAST_ADDRESS		0x3d
+#define	PXENV_STATUS_TFTP_NO_FILESIZE			0x3e
+#define	PXENV_STATUS_TFTP_INVALID_PACKET_SIZE		0x3f
+
+/* Reserved errors 0x40 to 0x4f) */
+
+/* DHCP/BOOTP errors (0x50 to 0x5f) */
+#define	PXENV_STATUS_DHCP_TIMEOUT			0x51
+#define	PXENV_STATUS_DHCP_NO_IP_ADDRESS			0x52
+#define	PXENV_STATUS_DHCP_NO_BOOTFILE_NAME		0x53
+#define	PXENV_STATUS_DHCP_BAD_IP_ADDRESS		0x54
+
+/* Driver errors (0x60 to 0x6f) */
+#define	PXENV_STATUS_UNDI_INVALID_FUNCTION		0x60
+#define	PXENV_STATUS_UNDI_MEDIATEST_FAILED		0x61
+#define	PXENV_STATUS_UNDI_CANNOT_INIT_NIC_FOR_MCAST	0x62
+#define	PXENV_STATUS_UNDI_CANNOT_INITIALIZE_NIC		0x63
+#define	PXENV_STATUS_UNDI_CANNOT_INITIALIZE_PHY		0x64
+#define	PXENV_STATUS_UNDI_CANNOT_READ_CONFIG_DATA	0x65
+#define	PXENV_STATUS_UNDI_CANNOT_READ_INIT_DATA		0x66
+#define	PXENV_STATUS_UNDI_BAD_MAC_ADDRESS		0x67
+#define	PXENV_STATUS_UNDI_BAD_EEPROM_CHECKSUM		0x68
+#define	PXENV_STATUS_UNDI_ERROR_SETTING_ISR		0x69
+#define	PXENV_STATUS_UNDI_INVALID_STATE			0x6a
+#define	PXENV_STATUS_UNDI_TRANSMIT_ERROR		0x6b
+#define	PXENV_STATUS_UNDI_INVALID_PARAMETER		0x6c
+
+/* ROM and NBP bootstrap errors (0x70 to 0x7f) */
+#define	PXENV_STATUS_BSTRAP_PROMPT_MENU			0x74
+#define	PXENV_STATUS_BSTRAP_MCAST_ADDR			0x76
+#define	PXENV_STATUS_BSTRAP_MISSING_LIST		0x77
+#define	PXENV_STATUS_BSTRAP_NO_RESPONSE			0x78
+#define	PXENV_STATUS_BSTRAP_FILE_TOO_BIG		0x79
+
+/* Environment NBP errors (0x80 to 0x8f) */
+
+/* Reserved errors (0x90 to 0x9f) */
+
+/* Miscellaneous errors (0xa0 to 0xaf) */
+#define	PXENV_STATUS_BINL_CANCELED_BY_KEYSTROKE		0xa0
+#define	PXENV_STATUS_BINL_NO_PXE_SERVER			0xa1
+#define	PXENV_STATUS_NOT_AVAILABLE_IN_PMODE		0xa2
+#define	PXENV_STATUS_NOT_AVAILABLE_IN_RMODE		0xa3
+
+/* BUSD errors (0xb0 to 0xbf) */
+#define	PXENV_STATUS_BUSD_DEVICE_NOT_SUPPORTED		0xb0
+
+/* Loader errors (0xc0 to 0xcf) */
+#define	PXENV_STATUS_LOADER_NO_FREE_BASE_MEMORY		0xc0
+#define	PXENV_STATUS_LOADER_NO_BC_ROMID			0xc1
+#define	PXENV_STATUS_LOADER_BAD_BC_ROMID		0xc2
+#define	PXENV_STATUS_LOADER_BAD_BC_RUNTIME_IMAGE	0xc3
+#define	PXENV_STATUS_LOADER_NO_UNDI_ROMID		0xc4
+#define	PXENV_STATUS_LOADER_BAD_UNDI_ROMID		0xc5
+#define	PXENV_STATUS_LOADER_BAD_UNDI_DRIVER_IMAGE	0xc6
+#define	PXENV_STATUS_LOADER_NO_PXE_STRUCT		0xc8
+#define	PXENV_STATUS_LOADER_NO_PXENV_STRUCT		0xc9
+#define	PXENV_STATUS_LOADER_UNDI_START			0xca
+#define	PXENV_STATUS_LOADER_BC_START			0xcb
+
+/*
+ * The range 0xd0 to 0xff is defined as "Vendor errors" by the PXE
+ * spec.  We place all our Etherboot-specific errors in this range.
+ * We also define some generic errors as aliases to the PXE errors.
+ *
+ */
+
+#define ENOMEM	PXENV_STATUS_OUT_OF_RESOURCES
+
+/* Data structures and declarations */
+
+#include "tables.h"
+
+extern int errno;
+
+extern const char * strerror ( int errno );
+
+struct errortab {
+	int errno;
+	const char *text;
+};
+
+#define __errortab __table(errortab,01)
+
+#endif /* ERRNO_H */