From 505a26ad9794776d7b018c81bf993751fba6b06f Mon Sep 17 00:00:00 2001
From: Michal Soltys <soltys@ziu.info>
Date: Sun, 22 Aug 2010 23:31:55 +0200
Subject: [PATCH] chain, options: fixes, additions

- add 'bss=' option
- update usage()
- ommited offsets in 'file=' and 'sect=' default to 0x7c00 now
- cosmetics

Signed-off-by: Michal Soltys <soltys@ziu.info>
---
 com32/chain/chain.c   | 16 ++++------------
 com32/chain/options.c | 40 +++++++++++++++++++++++++++++-----------
 com32/chain/utility.c |  1 +
 3 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/com32/chain/chain.c b/com32/chain/chain.c
index 88424db..7eed880 100644
--- a/com32/chain/chain.c
+++ b/com32/chain/chain.c
@@ -302,11 +302,11 @@ static void hide_unhide(const struct part_iter *_iter)
 
     if (_iter->type != typedos) {
 	error("Option 'hide' is only meaningful for legacy partition scheme.");
-	goto out;
+	goto bail;
     }
     if (!(mbr = disk_read_sectors(&_iter->di, 0, 1))) {
 	error("WARNING: Couldn't read MBR to hide/unhide partitions.\n");
-	goto out;
+	goto bail;
     }
 
     if (_iter->index < 1 || _iter->index > 4)
@@ -330,7 +330,7 @@ static void hide_unhide(const struct part_iter *_iter)
     if (write_back && disk_write_verify_sector(&_iter->di, 0, mbr))
 	error("WARNING: failed to write MBR for option 'hide'\n");
 
-out:
+bail:
     free(mbr);
 }
 
@@ -350,7 +350,6 @@ int find_dp(struct part_iter **_iter)
 	    error("Unable to find requested MBR signature.\n");
 	    goto bail;
 	}
-
     } else if (!strncmp(opt.drivename, "guid", 4)) {
 	if (str_to_guid(opt.drivename + 5, &gpt_guid))
 	    goto bail;
@@ -358,7 +357,6 @@ int find_dp(struct part_iter **_iter)
 	    error("Unable to find requested GPT disk or partition by guid.\n");
 	    goto bail;
 	}
-
     } else if (!strncmp(opt.drivename, "label", 5)) {
 	if (!opt.drivename[6]) {
 	    error("No label specified.\n");
@@ -368,7 +366,6 @@ int find_dp(struct part_iter **_iter)
 	    error("Unable to find requested GPT partition by label.\n");
 	    goto bail;
 	}
-
     } else if ((opt.drivename[0] == 'h' || opt.drivename[0] == 'f') &&
 	       opt.drivename[1] == 'd') {
 	hd = opt.drivename[0] == 'h' ? 0x80 : 0;
@@ -387,19 +384,14 @@ int find_dp(struct part_iter **_iter)
 		   "'boot' and 'fs' are meaningless.\n");
 	    goto bail;
 	}
-#if 0
 	/* offsets match, but in case it changes in the future */
 	if (sdi->c.filesystem == SYSLINUX_FS_ISOLINUX) {
 	    drive = sdi->iso.drive_number;
 	    fs_lba = *sdi->iso.partoffset;
 	} else {
-#endif
 	    drive = sdi->disk.drive_number;
 	    fs_lba = *sdi->disk.partoffset;
-#if 0
 	}
-#endif
-
 	if (disk_get_params(drive, &diskinfo))
 	    goto bail;
 	/* this will start iteration over disk emulation, possibly raw */
@@ -736,7 +728,7 @@ int main(int argc, char *argv[])
     printf("iter dsk: %d\n", iter->di.disk);
     printf("iter idx: %d\n", iter->index);
     printf("iter lba: %llu\n", iter->start_lba);
-    if (hand_area)
+    if (hidx >= 0)
 	printf("hand lba: %u\n", hand_area->start_lba);
 #endif
 
diff --git a/com32/chain/options.c b/com32/chain/options.c
index efb563d..3514124 100644
--- a/com32/chain/options.c
+++ b/com32/chain/options.c
@@ -10,13 +10,13 @@ int soi_s2n(char *ptr, unsigned int *seg,
 		       unsigned int *off,
 		       unsigned int *ip)
 {
-    unsigned int segval = 0, offval = 0, ipval = 0, val;
+    unsigned int segval = 0, offval = 0x7c00, ipval = 0x7c00, val;
     char *p;
 
     segval = strtoul(ptr, &p, 0);
-    if (*p == ':')
+    if (p[0] == ':' && p[1] && p[1] != ':')
 	offval = strtoul(p+1, &p, 0);
-    if (*p == ':')
+    if (p[0] == ':' && p[1] && p[1] != ':')
 	ipval = strtoul(p+1, NULL, 0);
 
     val = (segval << 4) + offval;
@@ -47,7 +47,10 @@ bail:
 
 void usage(void)
 {
-    static const char *const usage[] = { "\
+    unsigned int i;
+    static const char key[] = "Press any key...\n";
+    static const char *const usage[] = {
+"\
 Usage:\n\
     chain.c32 [options]\n\
     chain.c32 {fd|hd}<disk> [<partition>] [options]\n\
@@ -56,16 +59,18 @@ Usage:\n\
     chain.c32 label{:|=}<label> [<partition>] [options]\n\
     chain.c32 boot{,| }[<partition>] [options]\n\
     chain.c32 fs [options]\n\
-\nOptions ('no' prefix specify defaulti value):\n\
+", "\
+\nOptions ('no' prefix specify default value):\n\
     file=<loader>        Load and execute file\n\
     seg=<s[:o[:i]]>      Load file at <s:o>, jump to <s:i>\n\
     nofilebpb            Treat file in memory as BPB compatible\n\
     sect[=<s[:o[:i]]>]   Load sector at <s:o>, jump to <s:i>\n\
                          - defaults to 0:0x7C00:0x7C00\n\
+                         - ommited o/i values default 0x7C00\n\
     maps                 Map loaded sector into real memory\n\
     nosethid[den]        Set BPB's hidden sectors field\n\
     nosetgeo             Set BPB's sectors per track and heads fields\n\
-    nosetdrv[@<off>]     Set BPB's drive unit field at <o>\n\
+    nosetdrv[@<off>]     Set BPB's drive unit field at <off>\n\
                          - <off> defaults to autodetection\n\
                          - only 0x24 and 0x40 are accepted\n\
     nosetbpb             Enable set{hid,geo,drv}\n\
@@ -90,12 +95,17 @@ Usage:\n\
     grub=<loader>        Load GRUB Legacy stage2\n\
     grubcfg=<filename>   Set alternative config filename for GRUB Legacy\n\
     grldr=<loader>       Load GRUB4DOS grldr\n\
-\nPlease see doc/chain.txt for the detailed documentation.\n"
+    bss=<filename>       Emulate BSS (see doc/chain.txt for differences)\n\
+\nPlease see doc/chain.txt for the detailed documentation.\n\
+"
     };
-    error(usage[0]);
-    error("Press any key...\n");
-    wait_key();
-    error(usage[1]);
+    for (i = 0; i < sizeof(usage)/sizeof(usage[0]); i++) {
+	if (i) {
+	    error(key);
+	    wait_key();
+	}
+	error(usage[i]);
+    }
 }
 
 int parse_args(int argc, char *argv[])
@@ -112,6 +122,14 @@ int parse_args(int argc, char *argv[])
 	} else if (!strncmp(argv[i], "seg=", 4)) {
 	    if (soi_s2n(argv[i] + 4, &opt.fseg, &opt.foff, &opt.fip))
 		goto bail;
+	} else if (!strncmp(argv[i], "bss=", 4)) {
+	    opt.file = argv[i] + 4;
+	    opt.maps = false;
+	    opt.sethid = true;
+	    opt.setgeo = true;
+	    opt.setdrv = true;
+	    opt.drvoff = ~0u;
+	    opt.filebpb = true;
 	} else if (!strncmp(argv[i], "isolinux=", 9)) {
 	    opt.file = argv[i] + 9;
 	    opt.isolinux = true;
diff --git a/com32/chain/utility.c b/com32/chain/utility.c
index 9b978a6..5aa196d 100644
--- a/com32/chain/utility.c
+++ b/com32/chain/utility.c
@@ -112,3 +112,4 @@ uint32_t get_file_lba(const char *filename)
     return lba;
 }
 
+/* vim: set ts=8 sts=4 sw=4 noet: */
-- 
2.7.4