From 5a2d571f3687910260c45841725f2deb84c8f12e Mon Sep 17 00:00:00 2001
From: Hongxu Jia <hongxu.jia@windriver.com>
Date: Mon, 25 Apr 2022 18:18:00 +0800
Subject: [PATCH] add new option -eltorito-platform

Mkisofs now correctly supports El Torito multi boot entries by introducing
a Boot Dection Header before a list of alternate boot entries.

New option -eltorito-platform allows to set the El Torito platform id
for a boot entry or for a list of boot entries. Supported values for
the parameter are:
-   x86 the standard value vor x86 based PCs
-   PPC the Power PC platform
-   Mac The Apple Mac platform
-   efi EFI based boot for PCs
-   #   an arbitrary numerical value

Upstream-Status: Inappropriate [port from cdrtools]
https://github.com/jobermayr/cdrtools/commit/a50804fd61d75eb689a515dbfca6968ca2296fd7

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
---
 genisoimage/eltorito.c    | 73 +++++++++++++++++++++++++++++++++++++--
 genisoimage/genisoimage.c | 47 +++++++++++++++++++++++++
 genisoimage/genisoimage.h |  8 +++++
 genisoimage/iso9660.h     | 33 ++++++++++++++++--
 4 files changed, 157 insertions(+), 4 deletions(-)

diff --git a/genisoimage/eltorito.c b/genisoimage/eltorito.c
index d52e17e..a804988 100644
--- a/genisoimage/eltorito.c
+++ b/genisoimage/eltorito.c
@@ -56,6 +56,7 @@ static unsigned int bcat_de_flags;
 void	init_boot_catalog(const char *path);
 void	insert_boot_cat(void);
 static	void	get_torito_desc(struct eltorito_boot_descriptor *boot_desc);
+static	void	fill_boot_shdr(struct eltorito_sectionheader_entry *boot_shdr_entry, int arch);
 static	void	fill_boot_desc(struct eltorito_defaultboot_entry *boot_desc_entry,
 										struct eltorito_boot_entry_info *boot_entry);
 void	get_boot_entry(void);
@@ -282,7 +283,14 @@ get_torito_desc(struct eltorito_boot_descriptor *boot_desc)
 	struct directory_entry	*de2;	/* Boot catalog */
 	int			i;
 	int			offset;
+	int			arch = 0;
+	int			nentries = 0;
 	struct eltorito_defaultboot_entry boot_desc_record;
+	struct eltorito_sectionheader_entry boot_shdr_record;
+#ifdef __needed__
+	struct eltorito_section_entry boot_section_record;
+#endif
+	struct eltorito_sectionheader_entry *last_section_header = 0;
 
 	memset(boot_desc, 0, sizeof (*boot_desc));
 	boot_desc->type[0] = 0;
@@ -311,13 +319,22 @@ get_torito_desc(struct eltorito_boot_descriptor *boot_desc)
 	set_731(boot_desc->bootcat_ptr,
 		(unsigned int) get_733(de2->isorec.extent));
 
+	/*
+	 * If the platform id for the first (default) boot entry has not been
+	 * explicitly set, we default to EL_TORITO_ARCH_x86
+	 */
+	if ((first_boot_entry->type & ELTORITO_BOOT_ID) == 0) {
+		first_boot_entry->boot_platform = EL_TORITO_ARCH_x86;
+	}
+	arch = first_boot_entry->boot_platform;
+
 	/*
 	 * we have the boot image, so write boot catalog information
 	 * Next we write out the primary descriptor for the disc
 	 */
 	memset(&valid_desc, 0, sizeof (valid_desc));
 	valid_desc.headerid[0] = 1;
-	valid_desc.arch[0] = EL_TORITO_ARCH_x86;
+	valid_desc.arch[0] = arch;  /* Platform id for the default boot */
 
 	/*
 	 * we'll shove start of publisher id into id field,
@@ -351,8 +368,17 @@ get_torito_desc(struct eltorito_boot_descriptor *boot_desc)
 		current_boot_entry != NULL;
 		current_boot_entry = current_boot_entry->next,
 		offset += sizeof (boot_desc_record)) {
+		int newarch = arch;
 
-		if (offset >= SECTOR_SIZE) {
+		if (current_boot_entry->type & ELTORITO_BOOT_ID)
+			newarch = current_boot_entry->boot_platform;
+		else
+			current_boot_entry->boot_platform = arch;
+ 
+		/*
+		 * El Torito has no such limitation but we currently have...
+		 */
+		if (offset >= (SECTOR_SIZE - sizeof (boot_desc_record))) {
 #ifdef	USE_LIBSCHILY
 			comerrno(EX_BAD,
 			"Too many El Torito boot entries\n");
@@ -362,12 +388,53 @@ get_torito_desc(struct eltorito_boot_descriptor *boot_desc)
 			exit(1);
 #endif
 		}
+
+		if (current_boot_entry == first_boot_entry) {
+			;
+			/* EMPTY */
+		} else if ((current_boot_entry == first_boot_entry->next) ||
+			    (arch != newarch) ||
+			    (current_boot_entry->type & ELTORITO_SECTION_HEADER)) {
+			if (last_section_header)
+				set_721(&last_section_header->entry_count, nentries);
+			nentries = 1;
+			last_section_header = (struct eltorito_sectionheader_entry *)
+							(de2->table + offset);
+			fill_boot_shdr(&boot_shdr_record, newarch);
+			memcpy(de2->table + offset, &boot_shdr_record,
+						sizeof (boot_shdr_record));
+			offset += sizeof (boot_desc_record);
+		} else {
+			nentries++; /* Add entry to this section header */
+		}
+		/*
+		 * This works because a section entry has the same essential
+		 * layout as a default entry (and we do not populate the
+		 * selection criteria fields).
+		 */
+
 		fill_boot_desc(&boot_desc_record, current_boot_entry);
 		memcpy(de2->table + offset, &boot_desc_record,
 					sizeof (boot_desc_record));
 	}
+
+	if (last_section_header) {
+		set_721(&last_section_header->entry_count, nentries);
+		last_section_header->header_id[0] = EL_TORITO_SHDR_ID_LAST_SHDR;
+	}
+
 }/* get_torito_desc(... */
 
+static void
+fill_boot_shdr(boot_shdr_entry, arch)
+	struct eltorito_sectionheader_entry *boot_shdr_entry;
+	int                 arch;
+{
+	memset(boot_shdr_entry, 0, sizeof(struct eltorito_sectionheader_entry));
+	boot_shdr_entry->header_id[0] = EL_TORITO_SHDR_ID_SHDR;
+	boot_shdr_entry->platform_id[0] = arch;
+}
+
 static void
 fill_boot_desc(struct eltorito_defaultboot_entry *boot_desc_entry, 
 					struct eltorito_boot_entry_info *boot_entry)
@@ -678,7 +745,9 @@ get_boot_entry()
 	if (!first_boot_entry) {
 		first_boot_entry = current_boot_entry;
 		last_boot_entry = current_boot_entry;
+		current_boot_entry->boot_platform = EL_TORITO_ARCH_x86;
 	} else {
+		current_boot_entry->boot_platform = last_boot_entry->boot_platform;
 		last_boot_entry->next = current_boot_entry;
 		last_boot_entry = current_boot_entry;
 	}
diff --git a/genisoimage/genisoimage.c b/genisoimage/genisoimage.c
index 9089081..84ac3c2 100644
--- a/genisoimage/genisoimage.c
+++ b/genisoimage/genisoimage.c
@@ -271,6 +271,8 @@ struct rcopts {
 	char		**variable;
 };
 
+static int get_boot_platid(char *opt_arg);
+
 struct rcopts rcopt[] = {
 	{"PREP", &preparer},
 	{"PUBL", &publisher},
@@ -404,6 +406,7 @@ struct ld_option {
 
 #define	OPTION_ALLOW_LEADING_DOTS	1070
 #define	OPTION_PUBLISHER		1071
+#define	OPTION_PLATFORM			1072
 
 #ifdef		JIGDO_TEMPLATE
 #define	OPTION_JTT_OUTPUT		1101
@@ -528,6 +531,8 @@ static const struct ld_option ld_options[] =
 	'b', "FILE", "Set El Torito boot image name", ONE_DASH},
 	{{"eltorito-alt-boot", no_argument, NULL, OPTION_ALT_BOOT},
 	'\0', NULL, "Start specifying alternative El Torito boot parameters", ONE_DASH},
+	{{"eltorito-platform", required_argument, NULL, OPTION_PLATFORM},
+	'\0', "ID", "Set El Torito platform id for the next boot entry", ONE_DASH},
 	{{"sparc-boot", required_argument, NULL, 'B'},
 	'B', "FILES", "Set sparc boot image names", ONE_DASH},
 	{{"sunx86-boot", required_argument, NULL, OPTION_SUNX86BOOT},
@@ -1558,6 +1563,9 @@ int main(int argc, char *argv[])
 			 */
 			new_boot_entry();
 			break;
+		case OPTION_PLATFORM:
+			get_boot_platid(optarg);
+			break;
 		case OPTION_BOOTALPHA:
 			use_alphaboot++;
 			/* list of pathnames of boot images */
@@ -3829,3 +3837,42 @@ e_malloc(size_t size)
      memset(pt, 0, size);
 	return (pt);
 }
+
+static int
+get_boot_platid(char *opt_arg)
+{
+	long    val;
+	char    *ptr;
+
+	use_eltorito++;
+	if (streql(opt_arg, "x86")) {
+		val = EL_TORITO_ARCH_x86;
+	} else if (streql(opt_arg, "PPC")) {
+		val = EL_TORITO_ARCH_PPC;
+	} else if (streql(opt_arg, "Mac")) {
+		val = EL_TORITO_ARCH_PPC;
+	} else if (streql(opt_arg, "efi")) {
+		val = EL_TORITO_ARCH_EFI;
+	} else {
+		val = strtol(opt_arg, &ptr, 0);
+		if (*ptr || val < 0 || val >= 0x100) {
+			comerrno(EX_BAD, "Bad boot system ID.\n");
+		}
+	}
+
+	/*
+	 * If there is already a boot entry and the boot file name has been set
+	 * for this boot entry and the new platform id differs from the
+	 * previous value, we start a new boot section.
+	 */
+	if (current_boot_entry &&
+	    current_boot_entry->boot_image != NULL &&
+	    current_boot_entry->boot_platform != val) {
+	    new_boot_entry();
+	}
+	get_boot_entry();
+	current_boot_entry->type |= ELTORITO_BOOT_ID;
+	current_boot_entry->boot_platform = val;
+	return (1);
+}
+
diff --git a/genisoimage/genisoimage.h b/genisoimage/genisoimage.h
index 82c859b..1170d89 100644
--- a/genisoimage/genisoimage.h
+++ b/genisoimage/genisoimage.h
@@ -299,6 +299,14 @@ struct eltorito_boot_entry_info {
 	int		boot_info_table;
 	int		load_size;
 	int		load_addr;
+
+#define	ELTORITO_BOOT_ID    1
+#define	ELTORITO_SECTION_HEADER 2
+	int     type;
+	/*
+	 * Valid if (type & ELTORITO_BOOT_ID) != 0
+	 */
+	int     boot_platform;
 };
 
 extern int	goof;
diff --git a/genisoimage/iso9660.h b/genisoimage/iso9660.h
index c74c2a9..61b6fc0 100644
--- a/genisoimage/iso9660.h
+++ b/genisoimage/iso9660.h
@@ -62,6 +62,7 @@ struct iso_volume_descriptor {
 #define	EL_TORITO_ARCH_x86	0
 #define	EL_TORITO_ARCH_PPC	1
 #define	EL_TORITO_ARCH_MAC	2
+#define	EL_TORITO_ARCH_EFI	0xEF
 
 #define	EL_TORITO_BOOTABLE	0x88
 #define	EL_TORITO_NOT_BOOTABLE	0
@@ -159,10 +160,15 @@ struct eltorito_boot_descriptor {
 };
 
 /* Validation entry for El Torito */
+/*
+ * headerid must be 1
+ * id is the manufacturer ID
+ * cksum to make the sum of all shorts in this record 0
+ */
 struct eltorito_validation_entry {
 	char headerid			[ISODCL(1,    1)]; /* 711 */
 	char arch			[ISODCL(2,    2)];
-	char pad1			[ISODCL(3,    4)]; /* 711 */
+	char pad1			[ISODCL(3,    4)]; /* 721 */
 	char id				[ISODCL(5,   28)]; /* CD devel/man*/
 	char cksum			[ISODCL(29,  30)];
 	char key1			[ISODCL(31,  31)];
@@ -173,7 +179,7 @@ struct eltorito_validation_entry {
 struct eltorito_defaultboot_entry {
 	char boot_id			[ISODCL(1,    1)]; /* 711 */
 	char boot_media			[ISODCL(2,    2)];
-	char loadseg			[ISODCL(3,    4)]; /* 711 */
+	char loadseg			[ISODCL(3,    4)]; /* 721 */
 	char sys_type			[ISODCL(5,    5)];
 	char pad1			[ISODCL(6,    6)];
 	char nsect			[ISODCL(7,    8)];
@@ -181,6 +187,29 @@ struct eltorito_defaultboot_entry {
 	char pad2			[ISODCL(13,  32)];
 };
 
+/* El Torito section header entry in boot catalog */
+struct eltorito_sectionheader_entry {
+#define    EL_TORITO_SHDR_ID_SHDR      0x90
+#define    EL_TORITO_SHDR_ID_LAST_SHDR 0x91
+	char header_id          [ISODCL(1,    1)]; /* 711 */
+	char platform_id        [ISODCL(2,    2)];
+	char entry_count        [ISODCL(3,    4)]; /* 721 */
+	char id             [ISODCL(5,   32)];
+};
+
+/* El Torito section entry in boot catalog */
+struct eltorito_section_entry {
+	char boot_id            [ISODCL(1,    1)]; /* 711 */
+	char boot_media         [ISODCL(2,    2)];
+	char loadseg            [ISODCL(3,    4)]; /* 721 */
+	char sys_type           [ISODCL(5,    5)];
+	char pad1           [ISODCL(6,    6)];
+	char nsect          [ISODCL(7,    8)];
+	char bootoff            [ISODCL(9,   12)];
+	char sel_criteria       [ISODCL(13,  13)];
+	char vendor_sel_criteria    [ISODCL(14,  32)];
+};
+
 /*
  * XXX JS: The next two structures have odd lengths!
  * Some compilers (e.g. on Sun3/mc68020) padd the structures to even length.
-- 
2.27.0