initial checkout from wrc

1 files changed, 248 insertions, 0 deletions

diff --git a/util/listblob.c b/util/listblob.c
new file mode 100644
index 0000000..07523a6
--- /dev/null
+++ b/util/listblob.c
@@ -0,0 +1,248 @@
+/**
+** @file	listblob.c
+**
+** @author	Warren R. Carithers
+**
+** Examine a binary blob of ELF files.
+*/
+#define	_DEFAULT_SOURCE
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <ctype.h>
+
+/*
+** Blob file organization
+**
+** The file begins with a four-byte magic number and a four-byte integer
+** indicating the number of ELF files contained in the blob. This is
+** followed by an array of 32-byte file entries, and then the contents
+** of the ELF files in the order they appear in the program file table.
+**
+**		Bytes        Contents
+**		-----        ----------------------------
+**		0 - 3        File magic number ("BLB\0")
+**      4 - 7        Number of ELF files in blob ("n")
+**      8 - n*32+8   Program file table
+**      n*32+9 - ?   ELF file contents
+**
+** Each program file table entry contains the following information:
+**
+** 		name         File name (up to 19 characters long)
+**		offset       Byte offset to the ELF header for this file
+**		size         Size of this ELF file, in bytes
+**		flags        Flags related to this file
+*/
+
+// blob header: 8 bytes
+typedef struct header_s {
+	char magic[4];
+	uint32_t num;
+} header_t;
+
+// The program table entry is 32 bytes long. To accomplish this, the
+// name field is 20 bytes long, which allows file names of 19 characters
+// (followed by a trailing NUL byte).
+//
+// If that field is made longer, it should be incremented in multiples
+// of four to avoid the insertion of padding bytes.
+#define NAMELEN      20
+
+// program descriptor: 32 bytes
+typedef struct prog_s {
+	char name[NAMELEN];  // truncated name (19 chars plus NUL)
+	uint32_t offset;     // offset from the beginning of the blob
+	uint32_t size;       // size of this ELF module
+	uint32_t flags;      // miscellaneous flags
+} prog_t;
+
+// modules must be written as multiples of eight bytes
+#define FL_ROUNDUP     0x00000001
+
+// mask for mod 8 checking
+#define FSIZE_MASK     0x00000007
+
+// program list entry
+typedef struct node_s {
+	prog_t *data;
+	struct node_s *next;
+} node_t;
+
+node_t *progs, *last_prog;   // list pointers
+uint32_t n_progs;            // number of files being copied
+uint32_t offset;             // current file area offset
+bool defs  = false;          // print CPP #defines?
+bool enums = false;          // print C enums?
+
+// header string for the userids.h file
+const char header[] =
+"/**\n"
+"** @file	userids.h\n"
+"**\n"
+"** @author	Warren R. Carithers\n"
+"**\n"
+"** @brief	IDs for user-level programs\n"
+"**\n"
+"** NOTE: this file is automatically generated when the user.img file\n"
+"** is created. Do not edit this manually!\n"
+"*/\n"
+"\n"
+"#ifndef USERIDS_H_\n"
+"#define USERIDS_H_\n"
+"\n"
+"#ifndef ASM_SRC\n"
+"/*\n"
+"** These IDs are used to identify the various user programs.\n"
+"** Each call to exec() will provide one of these as the first\n"
+"** argument.\n"
+"**\n"
+"** This list should be updated if/when the collection of\n"
+"** user processes changes.\n"
+"*/\n"
+"enum users_e {"
+;
+
+// trailer string for the userids.h file
+const char trailer[] =
+"\n\t// sentinel\n\t, N_USERS\n"
+"};\n"
+"#endif  /* !ASM_SRC */\n"
+"\n"
+"#endif"
+;
+
+/**
+** Name:	process
+**
+** Process a program list entry
+**
+** @param num   Program list index
+** @param prog  Pointer to the program list entry
+*/
+void process( uint32_t num, prog_t *prog ) {
+
+	if( defs || enums ) {
+
+		char *slash = strrchr( prog->name, '/' );
+		if( slash == NULL ) {
+			slash = prog->name;
+		} else {
+			++slash;
+		}
+
+		slash[0] = toupper(slash[0]);
+
+		if( defs ) {
+
+			// just printing #define statements
+			printf( "#define %-15s %2d\n", prog->name, num );
+
+		} else {
+
+			// printing a new userids.h file
+			if( num == 0 ) {
+				// first one, so print the file header
+				puts( header );
+				putchar( '\t' );
+			} else {
+				// second or later entry; limit to 8 per line
+				fputs( ((num & 0x7) == 0 ) ?  ",\n\t" : ", ", stdout );
+			}
+			printf( "%s", prog->name );
+		}
+
+	} else {
+
+		// just printing information
+		printf( "Entry %2d:  ", num );
+		printf( "%-s,", prog->name );
+		printf( " offset 0x%x, size 0x%x, flags %08x\n",
+				prog->offset, prog->size, prog->flags );
+	}
+}
+
+void usage( char *name ) {
+	fprintf( stderr, "usage: %s [-d | -e] blob_name\n", name );
+}
+
+int main( int argc, char *argv[] ) {
+
+	if( argc < 2 || argc > 3) {
+		usage( argv[0] );
+		exit( 1 );
+	}
+	
+	int nameix = 1;
+
+	// could use getopt() for this, but this is easy enough
+	if( argc == 3 ) {
+		if( strcmp(argv[1],"-d") == 0 ) {
+			defs = true;
+		} else if( strcmp(argv[1],"-e") == 0 ) {
+			enums = true;
+		} else {
+			usage( argv[0] );
+			exit( 1 );
+		}
+		nameix = 2;
+	}
+
+	char *name = argv[nameix];
+
+	int fd = open( name, O_RDONLY );
+	if( fd < 0 ) {
+		perror( name );
+		exit( 1 );
+	}
+
+	header_t hdr;
+
+	int n = read( fd, &hdr, sizeof(header_t) );
+	if( n != sizeof(header_t) ) {
+		fprintf( stderr, "%s: header read returned only %d bytes\n", name, n );
+		close( fd );
+		exit( 1 );
+	}
+
+	if( strcmp(hdr.magic,"BLB") != 0 ) {
+		fprintf( stderr, "%s: bad magic number\n", name );
+		close( fd );
+		exit( 1 );
+	}
+
+	if( hdr.num < 1 ) {
+		fprintf( stderr, "%s: no programs in blob?\n", name );
+		close( fd );
+		exit( 1 );
+	}
+
+	prog_t progs[hdr.num];
+
+	n = read( fd, progs, hdr.num * sizeof(prog_t) );
+	if( n != (int) (hdr.num * sizeof(prog_t)) ) {
+
+		fprintf( stderr, "%s: prog table only %d bytes, expected %lu\n",
+				name, n, hdr.num * sizeof(prog_t) );
+		close( fd );
+		exit( 1 );
+	}
+
+	for( uint32_t i = 0; i < hdr.num; ++i ) {
+		process( i, &progs[i] );
+	}
+
+	if( enums ) {
+		// print the file trailer
+		puts( trailer );
+	}
+
+	close( fd );
+	return 0;
+
+}