Author: jhb
Date: Thu Apr 28 17:44:24 2011
New Revision: 221177
URL: http://svn.freebsd.org/changeset/base/221177

Log:
  Due to space constraints, the UFS boot2 and boot1 use an evil hack where
  boot2 calls back into boot1 to perform disk reads.  The ZFS MBR boot blocks
  do not have the same space constraints, so remove this hack for ZFS.
  While here, remove commented out code to support C/H/S addressing from
  zfsldr.  The ZFS and GPT bootstraps always just use EDD LBA addressing.
  
  MFC after:    2 weeks

Modified:
  head/sys/boot/i386/boot2/Makefile
  head/sys/boot/i386/common/drv.c
  head/sys/boot/i386/zfsboot/Makefile
  head/sys/boot/i386/zfsboot/zfsldr.S

Modified: head/sys/boot/i386/boot2/Makefile
==============================================================================
--- head/sys/boot/i386/boot2/Makefile   Thu Apr 28 17:36:26 2011        
(r221176)
+++ head/sys/boot/i386/boot2/Makefile   Thu Apr 28 17:44:24 2011        
(r221177)
@@ -32,6 +32,7 @@ CFLAGS=       -Os \
        -mno-align-long-strings \
        -mrtd \
        -mregparm=3 \
+       -DUSE_XREAD \
        -D${BOOT2_UFS} \
        -DFLAGS=${BOOT_BOOT1_FLAGS} \
        -DSIOPRT=${BOOT_COMCONSOLE_PORT} \

Modified: head/sys/boot/i386/common/drv.c
==============================================================================
--- head/sys/boot/i386/common/drv.c     Thu Apr 28 17:36:26 2011        
(r221176)
+++ head/sys/boot/i386/common/drv.c     Thu Apr 28 17:44:24 2011        
(r221177)
@@ -26,7 +26,7 @@ __FBSDID("$FreeBSD$");
 #include "rbx.h"
 #include "util.h"
 #include "drv.h"
-#ifndef GPT
+#ifdef USE_XREAD
 #include "xreadorg.h"
 #endif
 
@@ -58,7 +58,7 @@ drvsize(struct dsk *dskp)
 }
 #endif /* GPT */
 
-#ifdef GPT
+#ifndef USE_XREAD
 static struct {
        uint16_t        len;
        uint16_t        count;
@@ -66,7 +66,7 @@ static struct {
        uint16_t        seg;
        uint64_t        lba;
 } packet;
-#endif /* GPT */
+#endif
 
 int
 drvread(struct dsk *dskp, void *buf, daddr_t lba, unsigned nblk)
@@ -75,7 +75,7 @@ drvread(struct dsk *dskp, void *buf, dad
 
        if (!OPT_CHECK(RBX_QUIET))
                printf("%c\b", c = c << 8 | c >> 24);
-#ifdef GPT
+#ifndef USE_XREAD
        packet.len = 0x10;
        packet.count = nblk;
        packet.off = VTOPOFF(buf);
@@ -87,7 +87,7 @@ drvread(struct dsk *dskp, void *buf, dad
        v86.edx = dskp->drive;
        v86.ds = VTOPSEG(&packet);
        v86.esi = VTOPOFF(&packet);
-#else  /* !GPT */
+#else  /* USE_XREAD */
        v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
        v86.addr = XREADORG;            /* call to xread in boot1 */
        v86.es = VTOPSEG(buf);
@@ -95,7 +95,7 @@ drvread(struct dsk *dskp, void *buf, dad
        v86.ebx = VTOPOFF(buf);
        v86.ecx = lba >> 32;
        v86.edx = nblk << 8 | dskp->drive;
-#endif /* !GPT */
+#endif /* USE_XREAD */
        v86int();
        if (V86_CY(v86.efl)) {
                printf("%s: error %u lba %u\n",

Modified: head/sys/boot/i386/zfsboot/Makefile
==============================================================================
--- head/sys/boot/i386/zfsboot/Makefile Thu Apr 28 17:36:26 2011        
(r221176)
+++ head/sys/boot/i386/zfsboot/Makefile Thu Apr 28 17:44:24 2011        
(r221177)
@@ -6,9 +6,6 @@ FILES=          zfsboot
 
 NM?=           nm
 
-# A value of 0x80 enables LBA support.
-BOOT_BOOT1_FLAGS?=     0x80
-
 BOOT_COMCONSOLE_PORT?= 0x3f8
 BOOT_COMCONSOLE_SPEED?= 9600
 B2SIOFMT?=     0x3
@@ -25,7 +22,6 @@ CFLAGS=       -DBOOTPROG=\"zfsboot\" \
        -mno-align-long-strings \
        -mrtd \
        -DBOOT2 \
-       -DFLAGS=${BOOT_BOOT1_FLAGS} \
        -DSIOPRT=${BOOT_COMCONSOLE_PORT} \
        -DSIOFMT=${B2SIOFMT} \
        -DSIOSPD=${BOOT_COMCONSOLE_SPEED} \
@@ -64,8 +60,7 @@ zfsldr.out: zfsldr.o
        ${LD} ${LDFLAGS} -e start -Ttext ${ORG1} -o ${.TARGET} zfsldr.o
 
 CLEANFILES+=   zfsboot2 zfsboot.ld zfsboot.ldr zfsboot.bin zfsboot.out \
-               zfsboot.o zfsboot.s zfsboot.s.tmp xreadorg.h sio.o cons.o \
-               drv.o util.o
+               zfsboot.o zfsboot.s zfsboot.s.tmp sio.o cons.o drv.o util.o
 
 # We currently allow 65536 bytes for zfsboot - in practice it could be
 # any size up to 3.5Mb but keeping it fixed size simplifies zfsldr.
@@ -92,20 +87,13 @@ zfsboot.out: ${BTXCRT} zfsboot.o sio.o d
 
 zfsboot.o: zfsboot.s
 
-SRCS=  zfsboot.c xreadorg.h
+SRCS=  zfsboot.c
 
-zfsboot.s: zfsboot.c xreadorg.h ${.CURDIR}/../../zfs/zfsimpl.c
+zfsboot.s: zfsboot.c ${.CURDIR}/../../zfs/zfsimpl.c
        ${CC} ${CFLAGS} -S -o zfsboot.s.tmp ${.CURDIR}/zfsboot.c
        sed -e '/align/d' -e '/nop/d' < zfsboot.s.tmp > zfsboot.s
        rm -f zfsboot.s.tmp
 
-xreadorg.h: zfsldr.out
-       ${NM} -t d ${.ALLSRC} | awk '/([0-9])+ T xread/ \
-           { x = $$1 - ORG1; \
-           printf("#define XREADORG %#x\n", REL1 + x) }' \
-           ORG1=`printf "%d" ${ORG1}` \
-           REL1=`printf "%d" ${REL1}` > ${.TARGET}
-
 .if ${MACHINE_CPUARCH} == "amd64"
 beforedepend zfsboot.s: machine
 CLEANFILES+=   machine

Modified: head/sys/boot/i386/zfsboot/zfsldr.S
==============================================================================
--- head/sys/boot/i386/zfsboot/zfsldr.S Thu Apr 28 17:36:26 2011        
(r221176)
+++ head/sys/boot/i386/zfsboot/zfsldr.S Thu Apr 28 17:44:24 2011        
(r221177)
@@ -30,16 +30,12 @@
                .set PRT_NUM,0x4                # Partitions
                .set PRT_BSD,0xa5               # Partition type
 
-/* Flag Bits */
-               .set FL_PACKET,0x80             # Packet mode
-
 /* Misc. Constants */
                .set SIZ_PAG,0x1000             # Page size
                .set SIZ_SEC,0x200              # Sector size
 
                .set NSECT,0x80
                .globl start
-               .globl xread
                .code16
 
 start:         jmp main                        # Start recognizably
@@ -49,7 +45,7 @@ start:                jmp main                        # Start 
recognizably
  * FAT disks have this at the start of their MBR. While normal BIOS's will
  * work fine without this section, IBM's El Torito emulation "fixes" up the
  * BPB by writing into the memory copy of the MBR. Rather than have data
- * written into our xread routine, we'll define a BPB to work around it.
+ * written into our code, we'll define a BPB to work around it.
  * The data marked with (T) indicates a field required for a ThinkPad to
  * recognize the disk and (W) indicates fields written from IBM BIOS code.
  * The use of the BPB is based on what OpenBSD and NetBSD implemented in
@@ -80,34 +76,7 @@ ebpb:                .byte   0               # BIOS physical 
drive nu
 
                .org 0x25,0x90
 /*
- * Trampoline used by boot2 to call read to read data from the disk via
- * the BIOS.  Call with:
- *
- * %ecx:%eax   - long    - LBA to read in
- * %es:(%bx)   - caddr_t - buffer to read data into
- * %dl         - byte    - drive to read from
- * %dh         - byte    - num sectors to read
- */
-
-xread:         push %ss                        # Address
-               pop %ds                         #  data
-/*
- * Setup an EDD disk packet and pass it to read
- */
-xread.1:       pushl %ecx                      # Starting absolute block
-               pushl %eax                      #  block number
-               push %es                        # Address of
-               push %bx                        #  transfer buffer
-               xor %ax,%ax                     # Number of
-               movb %dh,%al                    #  blocks to
-               push %ax                        #  transfer
-               push $0x10                      # Size of packet
-               mov %sp,%bp                     # Packet pointer
-               callw read                      # Read from disk
-               lea 0x10(%bp),%sp               # Clear stack
-               lret                            # To far caller
-/*
- * Load the rest of boot2 and BTX up, copy the parts to the right locations,
+ * Load the rest of zfsboot2 and BTX up, copy the parts to the right locations,
  * and start it all up.
  */
 
@@ -181,7 +150,7 @@ main.4:     xor %dx,%dx                     # 
Partition:drive
  * itself to 0x9000 - doing it in this order means that none of the
  * memcpy regions overlap which would corrupt the copy.  Normally, BTX
  * clients start at MEM_USR, or 0xa000, but when we use btxld to
- * create boot2, we use an entry point of 0x2000.  That entry point is
+ * create zfsboot2, we use an entry point of 0x2000.  That entry point is
  * relative to MEM_USR; thus boot2.bin starts at 0xc000.
  *
  * The load area and the target area for the client overlap so we have
@@ -241,15 +210,29 @@ seta20.3: sti                             # Enable 
interrupts
 
 
 /*
- * Trampoline used to call read from within boot1.
+ * Trampoline used to call read from within zfsldr.  Sets up an EDD
+ * packet on the stack and passes it to read.
+ *
+ * %eax                - int     - LBA to read in relative to partition start
+ * %dl         - byte    - drive to read from
+ * %dh         - byte    - num sectors to read
+ * %si         - ptr     - MBR partition entry
  */
 nread:         xor %eax,%eax                   # Sector offset in partition
-nread.1:       mov $MEM_BUF,%bx                # Transfer buffer
-               xor %ecx,%ecx                   # Get
+nread.1:       xor %ecx,%ecx                   # Get
                addl 0x8(%si),%eax              #  LBA
                adc $0,%ecx
-               push %cs                        # Read from
-               callw xread.1                   #  disk
+               pushl %ecx                      # Starting absolute block
+               pushl %eax                      #  block number
+               push %es                        # Address of
+               push $MEM_BUF                   #  transfer buffer
+               xor %ax,%ax                     # Number of
+               movb %dh,%al                    #  blocks to
+               push %ax                        #  transfer
+               push $0x10                      # Size of packet
+               mov %sp,%bp                     # Packet pointer
+               callw read                      # Read from disk
+               lea 0x10(%bp),%sp               # Clear stack
                jnc return                      # If success, return
                mov $msg_read,%si               # Otherwise, set the error
                                                #  message and fall through to
@@ -293,9 +276,7 @@ return:     retw                            # To caller
  * %dl - byte     - drive number
  * stack - 10 bytes - EDD Packet
  */
-read:          testb $FL_PACKET,%cs:MEM_REL+flags-start # LBA support enabled?
-               jz read.1                       # No, use CHS
-               cmpb $0x80,%dl                  # Hard drive?
+read:          cmpb $0x80,%dl                  # Hard drive?
                jb read.1                       # No, use CHS
                mov $0x55aa,%bx                 # Magic
                push %dx                        # Save
@@ -311,73 +292,9 @@ read:              testb $FL_PACKET,%cs:MEM_REL+flag
                movb $0x42,%ah                  # BIOS: Extended
                int $0x13                       #  read
                retw                            # To caller
-#if 0  
-read.1:                push %dx                        # Save
-               movb $0x8,%ah                   # BIOS: Get drive
-               int $0x13                       #  parameters
-               movb %dh,%ch                    # Max head number
-               pop %dx                         # Restore
-               jc return                       # If error
-               andb $0x3f,%cl                  # Sectors per track
-               jz ereturn                      # If zero
-               cli                             # Disable interrupts
-               mov 0x8(%bp),%eax               # Get LBA
-               push %dx                        # Save
-               movzbl %cl,%ebx                 # Divide by
-               xor %edx,%edx                   #  sectors
-               div %ebx                        #  per track
-               movb %ch,%bl                    # Max head number
-               movb %dl,%ch                    # Sector number
-               inc %bx                         # Divide by
-               xorb %dl,%dl                    #  number
-               div %ebx                        #  of heads
-               movb %dl,%bh                    # Head number
-               pop %dx                         # Restore
-               cmpl $0x3ff,%eax                # Cylinder number supportable?
-               sti                             # Enable interrupts
-               ja ereturn                      # No, return an error
-               xchgb %al,%ah                   # Set up cylinder
-               rorb $0x2,%al                   #  number
-               orb %ch,%al                     # Merge
-               inc %ax                         #  sector
-               xchg %ax,%cx                    #  number
-               movb %bh,%dh                    # Head number
-               subb %ah,%al                    # Sectors this track
-               mov 0x2(%bp),%ah                # Blocks to read
-               cmpb %ah,%al                    # To read
-               jb read.2                       #  this
-#ifdef TRACK_AT_A_TIME
-               movb %ah,%al                    #  track
-#else
-               movb $1,%al                     #  one sector
-#endif
-read.2:        mov $0x5,%di                    # Try count
-read.3:        les 0x4(%bp),%bx                # Transfer buffer
-               push %ax                        # Save
-               movb $0x2,%ah                   # BIOS: Read
-               int $0x13                       #  from disk
-               pop %bx                         # Restore
-               jnc read.4                      # If success
-               dec %di                         # Retry?
-               jz read.6                       # No
-               xorb %ah,%ah                    # BIOS: Reset
-               int $0x13                       #  disk system
-               xchg %bx,%ax                    # Block count
-               jmp read.3                      # Continue
-read.4:        movzbw %bl,%ax                  # Sectors read
-               add %ax,0x8(%bp)                # Adjust
-               jnc read.5                      #  LBA,
-               incw 0xa(%bp)                   #  transfer
-read.5:        shlb %bl                        #  buffer
-               add %bl,0x5(%bp)                #  pointer,
-               sub %al,0x2(%bp)                #  block count
-               ja read.1                       # If not done
-read.6:        retw                            # To caller
-#else
 read.1:                mov $msg_chs,%si
                jmp error
 msg_chs:       .asciz "CHS not supported"
-#endif
 
 /* Messages */
 
@@ -386,8 +303,6 @@ msg_part:   .asciz "Boot"
 
 prompt:        .asciz " error\r\n"
 
-flags:         .byte FLAGS                     # Flags
-
                .org PRT_OFF,0x90
 
 /* Partition table */
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"

Reply via email to