Rhapsody Developer Release Copyright 1997 by Apple Computer, Inc. All Rights Reserved.
The MESH SCSI Driver is a software module that directly drives the MESH SCSI Hardware Bus Adapter, which is used as the internal SCSI bus on PowerSurge class machines.
The Developer Release marks the debut of the SCSI driver for the MESH internal bus. This driver permits hard-disk booting in place of network booting on PowerSurge class machines. The driver is of alpha quality; that is, it is functionally complete, but it contains some bugs. For Developer, the driver was included with the kernel after only limited testing. For example, it passed the "DISKTESTUTILS/drw" and "drand" tests, and it was used to copy files to a directory, on which fsck was run successfully afterwards. The driver also successfully copies files from a CD-ROM to a hard drive.
These bugs have appeared since the first build:
|
Reference |
1292956 |
|
Problem |
SCSI driver needs initiator ID from PRAM/NVRAM at Rhapsody boot. |
|
Description |
Initiator ID is hardwired to the traditional 0x07. |
|
Workaround |
None needed in the short term. |
|
Reference |
1370437 |
|
Problem |
Ofoto 2.0.2 reports an Unexpected error -6-105-1093 upon launch. |
|
Description |
This bug is a holdover from Copland. Ofoto needs legacy compatibility SCSI Manager calls. |
|
Workaround |
None needed in the short term. |
|
Reference |
1670605 |
|
Problem |
Driver needs to use standard DBDMA functions. |
|
Description |
Current version uses private functions to access the DBDMA. They should be converted to standard DBDMA function calls to save memory usage and for maintainability. |
|
Workaround |
None needed in the short term. |
|
Reference |
1670610 |
|
Problem |
Target's synchronous negotiation mishandled. |
|
Description |
Some IBM hard drives initiate negotiation for Synchronous mode at the earliest opportunity. The MESH Hardware Bus Adapter software mishandles this negotiation. |
|
Workaround |
None needed in the short term since no PowerSurge computers have internal IBM drives. |
|
Reference |
1670616 |
|
Problem |
Target Disconnect disabled. |
|
Description |
Driver does not allow targets to disconnect. Performance on an internal bus with multiple active targets might consequently suffer. |
|
Workaround |
None needed in the short term. |
|
Reference |
1670621 |
|
Problem |
Tagged Queueing disabled. |
|
Description |
The Tagged Queueing capability, although present in the code, is untested and is disabled in order to improve reliability (at the expense of performance) for the Developer Release. |
|
Workaround |
None needed in the short term. |
|
Reference |
1670623 |
|
Problem |
Hardwired addresses. |
|
Description |
Hacks such as hardwired addresses, put in the code for Developer Release expediency, must be cleaned up. |
|
Workaround |
None needed in the short term. |
|
Reference |
TBD |
|
Problem |
8-byte buffer alignment requirement. |
|
Description |
For Developer Release, the driver requires that buffers be 8-byte aligned. This requirement, which was needed to work around a DBDMA bug that occurs in limited circumstances, should be relaxed. |
|
Workaround |
None needed in the short term. |