Commit ba21f0cc authored Oct 12, 2015 by Maxim Samoylov Committed by Cornelia Huck Nov 11, 2015

pc-bios/s390-ccw: El Torito s390x boot entry check



Boot entry is considered compatible if boot image is Linux kernel
with matching S390 Linux magic string.

Empty boot images with sector_count == 0 are considered broken.

Signed-off-by: Maxim Samoylov <max7255@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

parent 866cac91

pc-bios/s390-ccw/bootmap.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -450,7 +450,16 @@ static void ipl_scsi(void)

		static bool is_iso_bc_entry_compatible(IsoBcSection *s)
		{
		return true;
		uint8_t magic_sec = (uint8_t )(sec + ISO_SECTOR_SIZE);

		if (s->unused \|\| !s->sector_count) {
		return false;
		}
		read_iso_sector(bswap32(s->load_rba), magic_sec,
		"Failed to read image sector 0");

		/* Checking bytes 8 - 32 for S390 Linux magic */
		return !_memcmp(magic_sec + 8, linux_s390_magic, 24);
		}

		static void load_iso_bc_entry(IsoBcSection *load)

pc-bios/s390-ccw/bootmap.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -495,6 +495,14 @@ typedef struct IsoBcHdr {
		uint8_t id[28];
		} __attribute__((packed)) IsoBcHdr;

		/*
		* Match two CCWs located after PSW and eight filler bytes.
		* From libmagic and arch/s390/kernel/head.S.
		*/
		const uint8_t linux_s390_magic[] = "\x02\x00\x00\x18\x60\x00\x00\x50\x02\x00"
		"\x00\x68\x60\x00\x00\x50\x40\x40\x40\x40"
		"\x40\x40\x40\x40";

		typedef struct IsoBcEntry {
		uint8_t id;
		union {