| Author | beginning argument ( Replies received: 7 ) |
| EtaPhi |
 Posted 02-06-2008 at 11:13 |
Registered on :
07-12-2004
From Italy
Messages : 182
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When I was debugging my code, I found a serious ST7 Assembler bug.
This STMicroelectronics assembler v4.49 bug deals with label constants.
Here an excerpt of the assembler listing:
135 E8A4 AEEB LD X,#Avvio_uWeb.H
136 E8A6 A648 LD A,#Avvio_uWeb.L
137 E8A8 81 RET
where Avvio_uWeb is defined later
653 .Avvio_uWeb
654 EB48 CDE124 CALL DetectIdle
If the listing was ok, the .sym file would contain an entry for Avvio_uWeb whose address should be $EB48.
The .sym file however contains:
'rom' CS
E310 main
E86F c_MasterKey
EB90 Avvio_uWeb
To my surprise, the $EB48 is now $EB90 (and in the final .s19 too)!
What went wrong?
EtaPhi
PS: My target is a ST7FLITE29 and I use the lastest version of ST Visual Develop (4.0.0)
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| RobertJ |
Posted 17-06-2008 at 17:48 |
Registered on :
06-24-2005
From France
Messages : 9
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It might be a bug.
Please send code (or excerpt) showing the problem.
RJ
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| EtaPhi |
Posted 18-06-2008 at 08:57 |
Registered on :
07-12-2004
From Italy
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Robert,
can you provide me your private address so that I can send you the whole project and keep it undisclosed?
Thank you in advance,
EtaPhi
[ This message was edited by: EtaPhi on 18-06-2008 12:33 ]
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| BrianM |
Posted 18-06-2008 at 12:11 |
Registered on :
03-05-2003
From UK (United Kingdom)
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Hi EtaPhi
Could you let us know (forum users) the results of this problem i.e. is it a bug or a coding issue?
Helps us if we have a similar problem in what to look for!
Re Brian
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| RobertJ |
Posted 18-06-2008 at 12:32 |
Registered on :
06-24-2005
From France
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Please send me the code at the following address
robert.jamier@st.com
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| EtaPhi |
Posted 18-06-2008 at 12:44 |
Registered on :
07-12-2004
From Italy
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Don't worry Brian,
I'm going to tell everyone the condition that triggers this bug, and how to work around it (with the help of Robert, of course).
Just wait for a while...
EtaPhi
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| RobertJ |
Posted 19-06-2008 at 11:55 |
Registered on :
06-24-2005
From France
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The code is correct but the absolute listing, which is generated after, is wrong.
Here is a case where the listing bug appears and how to get round it.
The variable array1 is declared in one file and used in another.
Its address is decremented and used as part of an operand. The array address (0x100) is two-byte long but the decremented address (0x99) is only one-byte long, leaving a possibility for optimization.
mapping.asm
segment byte at 100-17F 'ram1'
file1.asm
WORDS
segment 'ram1'
.array1 DS.b 32
file2.asm
EXTERN array1.w
segment 'rom'
LD ({array1-1},X),A
--> code generated for LD ({array1-1},X),A:
- in executable: D700FF
- in absolute listing: E7FF
--> the assembler is called a second time but only to generate the absolute listing from the map file, and this time the code is optimized.
Solution 1:
To remove the bug, move the declaration of array1 from file1.asm to file2.asm
file1.asm
file2.asm
WORDS
segment 'ram1'
.array1 DS.b 32
segment 'rom'
LD ({array1-1},X),A
--> code generated for "LD ({array1-1},X),A" in executable and listing: D700FF
Solution 2:
or better add address range for ram1 in file2.asm
file1.asm
file2.asm
WORDS
segment byte at 100-17F 'ram1'
.array1 DS.b 32
segment 'rom'
LD ({array1-1},X),A
--> code generated for "LD ({array1-1},X),A" in executable and listing: E7FF
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| EtaPhi |
Posted 19-06-2008 at 13:09 |
Registered on :
07-12-2004
From Italy
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Robert,
I am very grateful to you for your help.
It is nice to have this kind of support from ST!
My best wishes
EtaPhi
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Serious ST7 Assembler BUG