FormatDiskDLion.mesa
NOTE: At the time this module is started, the disk head must already have been initialized so that the result returned by DiskFace.GetDeviceAttributes is defined. This code assumes that all attached disks are of the same shape.
Last Edited by: Andrew Birrell December 6, 1983 1:15 pm
Last Edited by: Taft, December 16, 1983 5:45 pm
DIRECTORY
BasicTime USING [GMT],
Disk USING [Channel, Command, defaultTries, DoIO, GetBootChainLink, Label, PageCount, PageNumber, Request, Status],
DiskFace USING [DeviceHandle, DontCare, GetDeviceAttributes, GetNextDevice, nullDeviceHandle],
FormatDisk,
Rope USING [ROPE],
VM USING [AddressForPageNumber, Allocate, Free, Interval, Pin, Unpin];
FormatDiskDLion: MONITOR -- only one guy in here at a time!
IMPORTS Disk, DiskFace, VM
EXPORTS FormatDisk =
BEGIN OPEN FormatDisk;
Disk formatting and checking
BadPage: PUBLIC SIGNAL [page: Disk.PageNumber, correctable: BOOLEAN] = CODE;
Error: PUBLIC ERROR [page: Disk.PageNumber, status: Disk.Status] = CODE;
Sweep: PUBLIC ENTRY PROC [channel: Disk.Channel, operation: Operation, firstPage: Disk.PageNumber, pageCount: Disk.PageCount, label: LONG POINTER TO Disk.Label, data: LONG POINTER] =
BEGIN
Transfer[channel: channel, firstPage: firstPage, pageCount: pageCount, command: commandTable[operation], label: label, data: data, reportSoftErrors: TRUE];
END;
commandTable: ARRAY Operation OF Disk.Command = [
format: [write, write, write],
write: [verify, write, write],
read: [verify, read, read],
verify: [verify, verify, verify]];
Initial microcode
MicrocodeInstallFailure: PUBLIC SIGNAL [why: FailureType] = CODE;
InstallInitialMicrocode: PUBLIC ENTRY PROC [channel: Disk.Channel, getPage: PROC [ptr: LONG POINTER] RETURNS [ok: BOOLEAN]] =
BEGIN
label: Disk.Label;
vmInterval: VM.Interval ← VM.Allocate[count: 1];
pageBuffer: LONG POINTER ← VM.AddressForPageNumber[vmInterval.page];
thisPage: Disk.PageNumber ← hardUCodeStart;
prevPage: Disk.PageNumber ← [hardUCodeStart-1];
VM.Pin[vmInterval];
BEGIN ENABLE UNWIND => {VM.Unpin[vmInterval]; VM.Free[vmInterval]};
DO
ok: BOOLEAN;
IF (ok ← getPage[pageBuffer]) THEN
BEGIN ENABLE BadPage, Error =>
IF thisPage=hardUCodeStart THEN GOTO firstPageBad
ELSE {thisPage ← [thisPage+1]; RETRY};
IF thisPage>=hardUCodeStart+hardUCodeSize THEN ERROR MicrocodeInstallFailure[microcodeTooBig];
label ← initialMicrocodeLabel;
label.dontCare ← channel.GetBootChainLink[[thisPage+1]];
Transfer[channel: channel, firstPage: thisPage, pageCount: 1, command: [verify, write, write], label: @label, data: pageBuffer];
label ← initialMicrocodeLabel;
Transfer[channel: channel, firstPage: thisPage, pageCount: 1, command: [verify, verify, verify], label: @label, data: pageBuffer];
END;
IF thisPage#Disk.PageNumber[prevPage+1] OR ~ok THEN
BEGIN ENABLE BadPage, Error => GOTO flakeyPageFound;
label ← initialMicrocodeLabel;
Transfer[channel: channel, firstPage: prevPage, pageCount: 1, command: [verify, verify, read], label: @label, data: pageBuffer];
label ← initialMicrocodeLabel;
label.dontCare ← IF ok THEN channel.GetBootChainLink[thisPage] ELSE eofLink;
Transfer[channel: channel, firstPage: prevPage, pageCount: 1, command: [verify, write, write], label: @label, data: pageBuffer];
END;
IF ~ok THEN EXIT;
thisPage ← [(prevPage ← thisPage)+1];
REPEAT
firstPageBad => ERROR MicrocodeInstallFailure[firstPageBad];
flakeyPageFound => ERROR MicrocodeInstallFailure[flakeyPageFound];
ENDLOOP;
END;
VM.Unpin[vmInterval];
VM.Free[vmInterval];
END;
IdentifyInitialMicrocode: PUBLIC ENTRY PROC [channel: Disk.Channel] RETURNS [microcodeInstalled: BOOLEAN, time: BasicTime.GMT, name: Rope.ROPE] =
BEGIN
microcodeInstalled ← FALSE; -- DLion microcode does not follow this convention
END;
hardUCodeFileID: ARRAY [0..5) OF CARDINAL = [0, 0, 0, 0, 0]; -- boot microcode knows this ID
initialMicrocodeLabel: Disk.Label = [fileID: [abs[LOOPHOLE[hardUCodeFileID]]], filePage: 0, attributes: LOOPHOLE[0], dontCare: LOOPHOLE[LONG[0]]]; -- boot microcode knows this label. All pages of the initial microcode have the same label, except for the boot chain link which is filled in for every page. That is, the initial microcode is not a well-formed file.
nullLink: DiskFace.DontCare = LOOPHOLE[LONG[0]];
eofLink: DiskFace.DontCare = LOOPHOLE[LONG[-1]];
Reserved disk areas
hardUCodeStart: PUBLIC Disk.PageNumber; -- computed by Start
hardUCodeSize: PUBLIC Disk.PageCount; -- computed by Start
altoRegionJargon: PUBLIC Rope.ROPE ← NIL;
altoRegionsMax: PUBLIC INT ← 0;
altoRegionsStart: PUBLIC Disk.PageNumber ← [0];
altoRegionsSize: PUBLIC Disk.PageCount ← 0;
altoRegionsBottomUp: PUBLIC BOOL ← FALSE;
Initialization
Start: PUBLIC PROC =
BEGIN
sectors, heads: CARDINAL;
device: DiskFace.DeviceHandle = DiskFace.GetNextDevice[DiskFace.nullDeviceHandle];
IF device=DiskFace.nullDeviceHandle THEN ERROR;
[sectorsPerTrack: sectors, movingHeads: heads] ← DiskFace.GetDeviceAttributes[device];
hardUCodeStart ← [sectors]; -- one track reserved before start of microcode
hardUCodeSize ← (heads-1)*sectors; -- microcode fills rest of first cylinder
END;
Private
Transfer: PROC [channel: Disk.Channel, firstPage: Disk.PageNumber, pageCount: Disk.PageCount, command: Disk.Command, label: LONG POINTER TO Disk.Label, data: LONG POINTER, reportSoftErrors: BOOLEAN ← FALSE] =
! BadPage, Error;
BEGIN
retrying: BOOLEAN ← FALSE;
WHILE pageCount>0 DO
The idea here is as follows. If reportSoftErrors=FALSE then we just make a normal call and let the disk channel (and head) do all the error recovery. But if reportSoftErrors=TRUE, we initially request the disk channel (and head) to perform only one try so that we get to find out the exact address of any error. When an error occurs, we then retry just that one page with full error recovery enabled in order to discover whether the error is correctable.
request: Disk.Request ← [diskPage: firstPage, data: data, incrementDataPtr: FALSE, command: command, tries: IF reportSoftErrors AND ~retrying THEN 1 ELSE Disk.defaultTries, count: IF retrying THEN 1 ELSE pageCount];
countDone: Disk.PageCount;
status: Disk.Status;
[status: status, countDone: countDone] ← channel.DoIO[label: label, request: @request];
WITH s: status SELECT FROM
changed => ERROR Error[firstPage, status];
unchanged => SELECT s.status FROM
goodCompletion =>
IF retrying THEN {retrying ← FALSE; SIGNAL BadPage[firstPage, TRUE]};
notReady, recalibrateError, seekTimeout, memoryError, memoryFault, clientError, operationReset => ERROR Error[firstPage, status];
ENDCASE =>
BEGIN
IF ~retrying THEN retrying ← TRUE
ELSE BEGIN
retrying ← FALSE;
SIGNAL BadPage[firstPage, FALSE];
countDone ← countDone+1; -- skip over the bad page
label.filePage ← label.filePage+1;
END;
END;
ENDCASE => ERROR;
pageCount ← pageCount-countDone;
firstPage ← [firstPage+countDone];
ENDLOOP;
END;
END.