FormatDiskDorado.mesa
Last Edited by: Andrew Birrell December 6, 1983 1:15 pm
Last Edited by: Taft, January 31, 1984 11:54:45 am PST
Last Edited by: Willie-Sue, February 24, 1984 6:15:42 pm PST
DIRECTORY
BasicTime USING [FromPupTime, GMT, OutOfRange],
ConvertUnsafe USING [ToRope],
Disk USING [Channel, Command, defaultTries, DoIO, GetBootChainLink, Label, PageCount, PageNumber, Request, Status],
DiskFace USING [DeviceHandle, DontCare, GetDeviceAttributes, GetNextDevice, nullDeviceHandle],
FormatDisk,
PrincOps USING [zEXCH],
Rope USING [ROPE],
VM USING [AddressForPageNumber, Allocate, Free, Interval, Pin, Unpin];
FormatDiskDorado: MONITOR -- only one guy in here at a time!
IMPORTS BasicTime, ConvertUnsafe, DiskFace, Disk, 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
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
label: Disk.Label ← initialMicrocodeLabel;
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.dontCare ← LOOPHOLE[LONG[0]];
label.filePage ← thisPage-hardUCodeStart;
Transfer[channel: channel, firstPage: thisPage, pageCount: 1, command: [verify, write, write], label: @label, data: pageBuffer];
label.filePage ← thisPage-hardUCodeStart;
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.filePage ← prevPage-hardUCodeStart;
Transfer[channel: channel, firstPage: prevPage, pageCount: 1, command: [verify, verify, read], label: @label, data: pageBuffer];
label.filePage ← prevPage-hardUCodeStart;
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];
IF Disk.PageNumber[prevPage+1] < hardUCodeStart+hardUCodeSize THEN
Write different label at page after EOF or break in run so as to assure that a label check error will occur during reading and the bootChainLink will be noticed
BEGIN
label ← nullLabel;
Transfer[channel: channel, firstPage: Disk.PageNumber[prevPage+1], pageCount: 1, command: [verify, write, write], label: @label, data: pageBuffer ! BadPage, Error => CONTINUE];
END;
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
label: Disk.Label ← initialMicrocodeLabel;
vmInterval: VM.Interval ← VM.Allocate[count: 1];
uCodeHeader: LONG POINTER TO MicrocodeHeader ← VM.AddressForPageNumber[vmInterval.page];
VM.Pin[vmInterval];
microcodeInstalled ← FALSE;
BEGIN
Transfer[channel: channel, firstPage: hardUCodeStart, pageCount: 1, command: [verify, verify, read], label: @label, data: uCodeHeader !
BadPage, Error => GOTO error];
IF uCodeHeader.name.length IN [1..uCodeHeader.name.maxlength] AND uCodeHeader.name.maxlength<=maxNameLength THEN
BEGIN
time ← BasicTime.FromPupTime[GMTFromBCPLTime[uCodeHeader.createDate] !
BasicTime.OutOfRange => GOTO error];
name ← ConvertUnsafe.ToRope[@uCodeHeader.name];
microcodeInstalled ← TRUE;
END;
EXITS
error => NULL;
END;
VM.Unpin[vmInterval];
VM.Free[vmInterval];
END;
hardUCodeFileID: ARRAY [0..5) OF CARDINAL = [0, 0, 0, 064732B, 064732B]; -- 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
nullFileID: ARRAY [0..5) OF CARDINAL = [0, 0, 0, 0, 0];
nullLabel: Disk.Label = [fileID: [abs[LOOPHOLE[nullFileID]]], filePage: 0, attributes: LOOPHOLE[0], dontCare: LOOPHOLE[LONG[0]]];
nullLink: DiskFace.DontCare = LOOPHOLE[LONG[0]];
eofLink: DiskFace.DontCare = LOOPHOLE[LONG[-1]];
MicrocodeHeader: TYPE = MACHINE DEPENDENT RECORD [
version (0): CARDINAL,
mustBeZero (1): LONG CARDINAL,
createDate (3): BCPLTime,
name (5): StringBody];
BCPLTime: TYPE = RECORD [LONG CARDINAL];
GMTFromBCPLTime: PROCEDURE [BCPLTime] RETURNS [LONG CARDINAL] =
This returns what the BasicTime interface calls a "Pup time".
MACHINE CODE {PrincOps.zEXCH};
maxNameLength: CARDINAL = 40;
Reserved disk areas
hardUCodeStart: PUBLIC Disk.PageNumber ← [4];
hardUCodeSize: PUBLIC Disk.PageCount ← 3*28-4; -- 3 cylinders overhead
altoRegionJargon: PUBLIC Rope.ROPE ← "partitions";
altoRegionsMax: PUBLIC INT; -- computed by Start
altoRegionsStart: PUBLIC Disk.PageNumber ← [0]; -- overlaps with initial microcode
altoRegionsSize: PUBLIC Disk.PageCount ← 815*28; -- one surface of the disk
altoRegionsBottomUp: PUBLIC BOOL ← FALSE; -- prefer highest partition (5 or 19)
Initialization
Start: PUBLIC PROC =
BEGIN
device: DiskFace.DeviceHandle = DiskFace.GetNextDevice[DiskFace.nullDeviceHandle];
cylinders: CARDINAL;
IF device=DiskFace.nullDeviceHandle THEN ERROR;
cylinders← DiskFace.GetDeviceAttributes[device].cylinders;
-- moving heads is ALWAYS 1 for a "system" disk (RD0), so the following call doesn't work
altoRegionsMax ← DiskFace.GetDeviceAttributes[device].movingHeads;
altoRegionsMax← cylinders/815; -- terrible kludge !!!!!
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.