Date: Tue, 21 Jun 2011 21:02:28 +0200 From: Henri Hennebert <hlh@restart.be> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-stable@freebsd.org Subject: Re: ZFS boot inside on the second partition inside a slice Message-ID: <4E00EAC4.3050304@restart.be> In-Reply-To: <201106211351.45919.jhb@freebsd.org> References: <BANLkTi=drd8vY84_4jqDZTFK%2Bsq=n0Kx9g@mail.gmail.com> <201106211155.19231.jhb@freebsd.org> <4E00C3BE.3050004@restart.be> <201106211351.45919.jhb@freebsd.org>
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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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