- Split code shared by almost any boot loader into separate files and

  clean up most layering violations:

	sys/boot/i386/common/rbx.h:

		RBX_* defines
		OPT_SET()
		OPT_CHECK()

	sys/boot/common/util.[ch]:

		memcpy()
		memset()
		memcmp()
		bcpy()
		bzero()
		bcmp()
		strcmp()
		strncmp() [new]
		strcpy()
		strcat()
		strchr()
		strlen()
		printf()

	sys/boot/i386/common/cons.[ch]:

		ioctrl
		putc()
		xputc()
		putchar()
		getc()
		xgetc()
		keyhit() [now takes number of seconds as an argument]
		getstr()

	sys/boot/i386/common/drv.[ch]:

		struct dsk
		drvread()
		drvwrite() [new]
		drvsize() [new]

	sys/boot/common/crc32.[ch] [new]

	sys/boot/common/gpt.[ch] [new]

- Teach gptboot and gptzfsboot about new files. I haven't touched the
  rest, but there is still a lot of code duplication to be removed.

- Implement full GPT support. Currently we just read primary header and
  partition table and don't care about checksums, etc. After this change we
  verify checksums of primary header and primary partition table and if
  there is a problem we fall back to backup header and backup partition
  table.

- Clean up most messages to use prefix of boot program, so in case of an
  error we know where the error comes from, eg.:

	gptboot: unable to read primary GPT header

- If we can't boot, print boot prompt only once and not every five
  seconds.

- Honour newly added GPT attributes:

	bootme - this is bootable partition
	bootonce - try to boot from this partition only once
	bootfailed - we failed to boot from this partition

- Change boot order of gptboot to the following:

	1. Try to boot from all the partitions that have both 'bootme'
	   and 'bootonce' attributes one by one.
	2. Try to boot from all the partitions that have only 'bootme'
	   attribute one by one.
	3. If there are no partitions with 'bootme' attribute, boot from
	   the first UFS partition.

- The 'bootonce' functionality is implemented in the following way:

	1. Walk through all the partitions and when 'bootonce'
	   attribute is found without 'bootme' attribute, remove
	   'bootonce' attribute and set 'bootfailed' attribute.
	   'bootonce' attribute alone means that we tried to boot from
	   this partition, but boot failed after leaving gptboot and
	   machine was restarted.
	2. Find partition with both 'bootme' and 'bootonce' attributes.
	3. Remove 'bootme' attribute.
	4. Try to execute /boot/loader or /boot/kernel/kernel from that
	   partition. If succeeded we stop here.
	5. If execution failed, remove 'bootonce' and set 'bootfailed'.
	6. Go to 2.

   If whole boot succeeded there is new /etc/rc.d/gptboot script coming
   that will log all partitions that we failed to boot from (the ones with
   'bootfailed' attribute) and will remove this attribute. It will also
   find partition with 'bootonce' attribute - this is the partition we
   booted from successfully. The script will log success and remove the
   attribute.

   All the GPT updates we do here goes to both primary and backup GPT if
   they are valid. We don't touch headers or partition tables when
   checksum doesn't match.

Reviewed by:	arch (Message-ID: <20100917234542.GE1902@garage.freebsd.pl>)
Obtained from:	Wheel Systems Sp. z o.o. http://www.wheelsystems.com
MFC after:	2 weeks

1 files changed, 108 insertions, 0 deletions

diff --git a/sys/boot/common/crc32.c b/sys/boot/common/crc32.c
new file mode 100644
index 0000000..0325179
--- /dev/null
+++ b/sys/boot/common/crc32.c
@@ -0,0 +1,108 @@
+/*-
+ *  COPYRIGHT (C) 1986 Gary S. Brown.  You may use this program, or
+ *  code or tables extracted from it, as desired without restriction.
+ */
+
+/*
+ *  First, the polynomial itself and its table of feedback terms.  The
+ *  polynomial is
+ *  X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
+ *
+ *  Note that we take it "backwards" and put the highest-order term in
+ *  the lowest-order bit.  The X^32 term is "implied"; the LSB is the
+ *  X^31 term, etc.  The X^0 term (usually shown as "+1") results in
+ *  the MSB being 1
+ *
+ *  Note that the usual hardware shift register implementation, which
+ *  is what we're using (we're merely optimizing it by doing eight-bit
+ *  chunks at a time) shifts bits into the lowest-order term.  In our
+ *  implementation, that means shifting towards the right.  Why do we
+ *  do it this way?  Because the calculated CRC must be transmitted in
+ *  order from highest-order term to lowest-order term.  UARTs transmit
+ *  characters in order from LSB to MSB.  By storing the CRC this way
+ *  we hand it to the UART in the order low-byte to high-byte; the UART
+ *  sends each low-bit to hight-bit; and the result is transmission bit
+ *  by bit from highest- to lowest-order term without requiring any bit
+ *  shuffling on our part.  Reception works similarly
+ *
+ *  The feedback terms table consists of 256, 32-bit entries.  Notes
+ *
+ *      The table can be generated at runtime if desired; code to do so
+ *      is shown later.  It might not be obvious, but the feedback
+ *      terms simply represent the results of eight shift/xor opera
+ *      tions for all combinations of data and CRC register values
+ *
+ *      The values must be right-shifted by eight bits by the "updcrc
+ *      logic; the shift must be unsigned (bring in zeroes).  On some
+ *      hardware you could probably optimize the shift in assembler by
+ *      using byte-swap instructions
+ *      polynomial $edb88320
+ *
+ *
+ * CRC32 code derived from work by Gary S. Brown.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+
+#include "crc32.h"
+
+static uint32_t crc32_tab[] = {
+	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+	0xe963a535, 0x9e6495a3,	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+	0xf3b97148, 0x84be41de,	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,	0x14015c4f, 0x63066cd9,
+	0xfa0f3d63, 0x8d080df5,	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,	0x35b5a8fa, 0x42b2986c,
+	0xdbbbc9d6, 0xacbcf940,	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,	0x76dc4190, 0x01db7106,
+	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+uint32_t
+crc32(const void *buf, size_t size)
+{
+	const uint8_t *p = buf;
+	uint32_t crc;
+
+	crc = ~0U;
+	while (size--)
+		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
+	return (crc ^ ~0U);
+}