On 06/21/2011 19:51, John Baldwin wrote:
On Tuesday, June 21, 2011 12:15:58 pm Henri Hennebert wrote:
On 06/21/2011 17:55, John Baldwin wrote:
On Tuesday, June 21, 2011 10:50:14 am Henri Hennebert wrote:
On 06/21/2011 15:01, John Baldwin wrote:
Index: zfsldr.S
===================================================================
--- zfsldr.S (revision 223339)
+++ zfsldr.S (working copy)
@@ -234,9 +234,12 @@ nread.1: xor %ecx,%ecx # Get
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
- # the error routine
+ mov %ah,%al # Format
+ mov $read_err,%di # error
+ call hex8 # code
+ mov $msg_read,%si # Set the error message and
+ # fall through to the error
+ # routine
/*
* Print out the error message pointed to by %ds:(%si) followed
* by a prompt, wait for a keypress, and then reboot the machine.
@@ -296,12 +299,28 @@ read.1: mov $msg_chs,%si
jmp error
msg_chs: .asciz "CHS not supported"
+/*
+ * Convert AL to hex, saving the result to [EDI].
+ */
+hex8: push %ax # Save
+ shrb $0x4,%al # Do upper
+ call hex8.1 # 4
+ pop %ax # Restore
+hex8.1: andb $0xf,%al # Get lower 4
+ cmpb $0xa,%al # Convert
+ sbbb $0x69,%al # to hex
+ das # digit
+ orb $0x20,%al # To lower case
+ stosb # Save char
+ ret # (Recursive)
+
/* Messages */
-msg_read: .asciz "Read"
-msg_part: .asciz "Boot"
+msg_read: .ascii "Read error: "
+read_err: .asciz "XX"
+msg_part: .asciz "Boot error"
-prompt: .asciz " error\r\n"
+prompt: .asciz "\r\n"
.org PRT_OFF,0x90
I get
Read error: 01
Hmm, that would be 'invalid parameter'.
Can you add a 'foo: jmp foo' infinite loop and move it around to figure
out
which read call is failing?
main.5: mov %dx,MEM_ARG # Save args
movb $NSECT,%dh # Sector count
movl $1024,%eax # Offset to boot2
callw nread.1 # Read disk
foo: jmp foo
After this one I get
'Read error: 01'
Hmm, ok. NSECT changed in the MFC (it is now larger). Try this patch. It
changes the code to read zfsboot in one sector at a time:
I encounter 2 problems - see in you patch
Henri
Index: zfsldr.S
===================================================================
--- zfsldr.S (revision 223365)
+++ zfsldr.S (working copy)
@@ -16,7 +16,6 @@
*/
/* Memory Locations */
- .set MEM_REL,0x700 # Relocation address
.set MEM_ARG,0x900 # Arguments
.set MEM_ORG,0x7c00 # Origin
.set MEM_BUF,0x8000 # Load area
@@ -91,26 +90,19 @@ main: cld #
String ops inc
mov %cx,%ss # Set up
mov $start,%sp # stack
/*
- * Relocate ourself to MEM_REL. Since %cx == 0, the inc %ch sets
- * %cx == 0x100.
- */
- mov %sp,%si # Source
- mov $MEM_REL,%di # Destination
- incb %ch # Word count
- rep # Copy
- movsw # code
-/*
* If we are on a hard drive, then load the MBR and look for the first
* FreeBSD slice. We use the fake partition entry below that points to
* the MBR when we call nread. The first pass looks for the first active
* FreeBSD slice. The second pass looks for the first non-active FreeBSD
* slice if the first one fails.
*/
- mov $part4,%si # Partition
+ mov $part4,%si # Dummy partition
cmpb $0x80,%dl # Hard drive?
jb main.4 # No
- movb $0x1,%dh # Block count
- callw nread # Read MBR
+ xor %eax,%eax # Read MBR from
+ movw $MEM_BUF,%bx # first sector
+ movb $0x1,%dh # on disk into
+ callw nread # $MEM_BUF
mov $0x1,%cx # Two passes
main.1: mov $MEM_BUF+PRT_OFF,%si # Partition table
movb $0x1,%dh # Partition
@@ -161,10 +153,18 @@ main.4: xor %dx,%dx #
Partition:drive
* area and target area do not overlap.
*/
main.5: mov %dx,MEM_ARG # Save args
- movb $NSECT,%dh # Sector count
+ movb $NSECT,%cl # Sector count
movl $1024,%eax # Offset to boot2
- callw nread.1 # Read disk
-main.6: mov $MEM_BUF,%si # BTX (before reloc)
+ mov $MEM_BUF,%bx # Destination buffer
+main.6: pushal # Save params
+ movb $1,$dh # One sector
%dh
|
------------------------+
+ callw nread # Read disk
+ popal # Restore
+ incl %eax # Update for
+ add $SIZ_SEC,%bx # next sector
+ dec %cx # Last sector?
+ jncxz main.6 # If not, read another.
Error: no such instruction: `jncxz main.6'
Here I'm lost
+ mov $MEM_BUF,%si # BTX (before reloc)
mov 0xa(%si),%bx # Get BTX length and set
mov $NSECT*SIZ_SEC-1,%di # Size of load area (less one)
mov %di,%si # End of load
@@ -214,12 +214,12 @@ seta20.3: sti # Enable
interrupts
* packet on the stack and passes it to read.
*
* %eax - int - LBA to read in relative to partition start
+ * %es:%bx - ptr - destination address
* %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: xor %ecx,%ecx # Get
+nread: xor %ecx,%ecx # Get
addl 0x8(%si),%eax # LBA
adc $0,%ecx
pushl %ecx # Starting absolute block
@@ -234,9 +234,12 @@ seta20.3: sti # Enable
interrupts
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
- # the error routine
+ mov %ah,%al # Format
+ mov $read_err,%di # error
+ call hex8 # code
+ mov $msg_read,%si # Set the error message and
+ # fall through to the error
+ # routine
/*
* Print out the error message pointed to by %ds:(%si) followed
* by a prompt, wait for a keypress, and then reboot the machine.
@@ -296,12 +299,28 @@ read.1: mov $msg_chs,%si
jmp error
msg_chs: .asciz "CHS not supported"
+/*
+ * Convert AL to hex, saving the result to [EDI].
+ */
+hex8: push %ax # Save
+ shrb $0x4,%al # Do upper
+ call hex8.1 # 4
+ pop %ax # Restore
+hex8.1: andb $0xf,%al # Get lower 4
+ cmpb $0xa,%al # Convert
+ sbbb $0x69,%al # to hex
+ das # digit
+ orb $0x20,%al # To lower case
+ stosb # Save char
+ ret # (Recursive)
+
/* Messages */
-msg_read: .asciz "Read"
-msg_part: .asciz "Boot"
+msg_read: .ascii "Read error: "
+read_err: .asciz "XX"
+msg_part: .asciz "Boot error"
-prompt: .asciz " error\r\n"
+prompt: .asciz "\r\n"
.org PRT_OFF,0x90
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