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kolibrios/kernel/trunk/drivers/usbstor.asm
CleverMouse df6a761ad4 coalesce transfers in same direction 
git-svn-id: svn://kolibrios.org@4346 a494cfbc-eb01-0410-851d-a64ba20cac60
2013-12-12 16:03:06 +00:00

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; standard driver stuff
format MS COFF
DEBUG = 1
DUMP_PACKETS = 0
; this is for DEBUGF macro from 'fdo.inc'
__DEBUG__ = 1
__DEBUG_LEVEL__ = 1
include 'proc32.inc'
include 'imports.inc'
include 'fdo.inc'
public START
public version
; USB constants
DEVICE_DESCR_TYPE = 1
CONFIG_DESCR_TYPE = 2
STRING_DESCR_TYPE = 3
INTERFACE_DESCR_TYPE = 4
ENDPOINT_DESCR_TYPE = 5
DEVICE_QUALIFIER_DESCR_TYPE = 6
CONTROL_PIPE = 0
ISOCHRONOUS_PIPE = 1
BULK_PIPE = 2
INTERRUPT_PIPE = 3
; USB structures
virtual at 0
config_descr:
.bLength db ?
.bDescriptorType db ?
.wTotalLength dw ?
.bNumInterfaces db ?
.bConfigurationValue db ?
.iConfiguration db ?
.bmAttributes db ?
.bMaxPower db ?
.sizeof:
end virtual
virtual at 0
interface_descr:
.bLength db ?
.bDescriptorType db ?
.bInterfaceNumber db ?
.bAlternateSetting db ?
.bNumEndpoints db ?
.bInterfaceClass db ?
.bInterfaceSubClass db ?
.bInterfaceProtocol db ?
.iInterface db ?
.sizeof:
end virtual
virtual at 0
endpoint_descr:
.bLength db ?
.bDescriptorType db ?
.bEndpointAddress db ?
.bmAttributes db ?
.wMaxPacketSize dw ?
.bInterval db ?
.sizeof:
end virtual
; Mass storage protocol constants, USB layer
REQUEST_GETMAXLUN = 0xFE ; get max lun
REQUEST_BORESET = 0xFF ; bulk-only reset
; Mass storage protocol structures, USB layer
; Sent from host to device in the first stage of an operation.
struc command_block_wrapper
{
.Signature dd ? ; the constant 'USBC'
.Tag dd ? ; identifies response with request
.Length dd ? ; length of data-transport phase
.Flags db ? ; one of CBW_FLAG_*
CBW_FLAG_OUT = 0
CBW_FLAG_IN = 80h
.LUN db ? ; addressed unit
.CommandLength db ? ; the length of the following field
.Command rb 16
.sizeof:
}
virtual at 0
command_block_wrapper command_block_wrapper
end virtual
; Sent from device to host in the last stage of an operation.
struc command_status_wrapper
{
.Signature dd ? ; the constant 'USBS'
.Tag dd ? ; identifies response with request
.LengthRest dd ? ; .Length - (size of data which were transferred)
.Status db ? ; one of CSW_STATUS_*
CSW_STATUS_OK = 0
CSW_STATUS_FAIL = 1
CSW_STATUS_FATAL = 2
.sizeof:
}
virtual at 0
command_status_wrapper command_status_wrapper
end virtual
; Constants of SCSI layer
SCSI_REQUEST_SENSE = 3
SCSI_INQUIRY = 12h
SCSI_READ_CAPACITY = 25h
SCSI_READ10 = 28h
SCSI_WRITE10 = 2Ah
; Result of SCSI REQUEST SENSE command.
SENSE_UNKNOWN = 0
SENSE_RECOVERED_ERROR = 1
SENSE_NOT_READY = 2
SENSE_MEDIUM_ERROR = 3
SENSE_HARDWARE_ERROR = 4
SENSE_ILLEGAL_REQUEST = 5
SENSE_UNIT_ATTENTION = 6
SENSE_DATA_PROTECT = 7
SENSE_BLANK_CHECK = 8
; 9 is vendor-specific
SENSE_COPY_ABORTED = 10
SENSE_ABORTED_COMMAND = 11
SENSE_EQUAL = 12
SENSE_VOLUME_OVERFLOW = 13
SENSE_MISCOMPARE = 14
; 15 is reserved
; Structures of SCSI layer
; Result of SCSI INQUIRY request.
struc inquiry_data
{
.PeripheralDevice db ? ; lower 5 bits are PeripheralDeviceType
; upper 3 bits are PeripheralQualifier
.RemovableMedium db ? ; upper bit is RemovableMedium
; other bits are for compatibility
.Version db ? ; lower 3 bits are ANSI-Approved version
; next 3 bits are ECMA version
; upper 2 bits are ISO version
.ResponseDataFormat db ? ; lower 4 bits are ResponseDataFormat
; bit 6 is TrmIOP
; bit 7 is AENC
.AdditionalLength db ?
dw ? ; reserved
.Flags db ?
.VendorID rb 8 ; vendor ID, big-endian
.ProductID rb 16 ; product ID, big-endian
.ProductRevBE dd ? ; product revision, big-endian
.sizeof:
}
virtual at 0
inquiry_data inquiry_data
end virtual
struc sense_data
{
.ErrorCode db ? ; lower 7 bits are error code:
; 70h = current error,
; 71h = deferred error
; upper bit is InformationValid
.SegmentNumber db ? ; number of segment descriptor
; for commands COPY [+VERIFY], COMPARE
.SenseKey db ? ; bits 0-3 are one of SENSE_*
; bit 4 is reserved
; bit 5 is IncorrectLengthIndicator
; bits 6 and 7 are used by
; sequential-access devices
.Information dd ? ; command-specific
.AdditionalLength db ? ; length of data starting here
.CommandInformation dd ? ; command-specific
.AdditionalSenseCode db ? ; \ more detailed error code
.AdditionalSenseQual db ? ; / standard has a large table of them
.FRUCode db ? ; which part of device has failed
; (device-specific, not regulated)
.SenseKeySpecific rb 3 ; depends on SenseKey
.sizeof:
}
virtual at 0
sense_data sense_data
end virtual
; Device data
; USB Mass storage device has one or more logical units, identified by LUN,
; logical unit number. The highest value of LUN, that is, number of units
; minus 1, can be obtained via control request Get Max LUN.
virtual at 0
usb_device_data:
.ConfigPipe dd ? ; configuration pipe
.OutPipe dd ? ; pipe for OUT bulk endpoint
.InPipe dd ? ; pipe for IN bulk endpoint
.MaxLUN dd ? ; maximum Logical Unit Number
.LogicalDevices dd ? ; pointer to array of usb_unit_data
; 1 for a connected USB device, 1 for each disk device
; the structure can be freed when .NumReferences decreases to zero
.NumReferences dd ? ; number of references
.ConfigRequest rb 8 ; buffer for configuration requests
.LengthRest dd ? ; Length - (size of data which were transferred)
; All requests to a given device are serialized,
; only one request to a given device can be processed at a time.
; The current request and all pending requests are organized in the following
; queue, the head being the current request.
; NB: the queue must be device-wide due to the protocol:
; data stage is not tagged (unlike command_*_wrapper), so the only way to know
; what request the data are associated with is to guarantee that only one
; request is processing at the time.
.RequestsQueue rd 2
.QueueLock rd 3 ; protects .RequestsQueue
.InquiryData inquiry_data ; information about device
; data for the current request
.Command command_block_wrapper
.DeviceDisconnected db ?
.Status command_status_wrapper
.Sense sense_data
.sizeof:
end virtual
; Information about one logical device.
virtual at 0
usb_unit_data:
.Parent dd ? ; pointer to parent usb_device_data
.LUN db ? ; index in usb_device_data.LogicalDevices array
.DiskIndex db ? ; for name "usbhd<index>"
.MediaPresent db ?
db ? ; alignment
.DiskDevice dd ? ; handle of disk device or NULL
.SectorSize dd ? ; sector size
; For some devices, the first request to the medium fails with 'unit not ready'.
; When the code sees this status, it retries the command several times.
; Two following variables track the retry count and total time for those;
; total time is currently used only for debug output.
.UnitReadyAttempts dd ?
.TimerTicks dd ?
.sizeof:
end virtual
; This is the structure for items in the queue usb_device_data.RequestsQueue.
virtual at 0
request_queue_item:
.Next dd ? ; next item in the queue
.Prev dd ? ; prev item in the queue
.ReqBuilder dd ? ; procedure to fill command_block_wrapper
.Buffer dd ? ; input or output data
; (length is command_block_wrapper.Length)
.Callback dd ? ; procedure to call in the end of transfer
.UserData dd ? ; passed as-is to .Callback
; There are 3 possible stages of any request, one of them optional:
; command stage (host sends command_block_wrapper to device),
; optional data stage,
; status stage (device sends command_status_wrapper to host).
; Also, if a request fails, the code queues additional request
; SCSI_REQUEST_SENSE; sense_data from SCSI_REQUEST_SENSE
; contains some information about the error.
.Stage db ?
.sizeof:
end virtual
section '.flat' code readable align 16
; The start procedure.
proc START
virtual at esp
dd ? ; return address
.reason dd ? ; DRV_ENTRY or DRV_EXIT
end virtual
; 1. Test whether the procedure is called with the argument DRV_ENTRY.
; If not, return 0.
xor eax, eax ; initialize return value
cmp [.reason], 1 ; compare the argument
jnz .nothing
; 2. Initialize: we have one global mutex.
mov ecx, free_numbers_lock
call MutexInit
; 3. Register self as a USB driver.
; The name is my_driver = 'usbstor'; IOCTL interface is not supported;
; usb_functions is an offset of a structure with callback functions.
stdcall RegUSBDriver, my_driver, 0, usb_functions
; 4. Return the returned value of RegUSBDriver.
.nothing:
ret 4
endp
; Helper procedures to work with requests queue.
; Add a request to the queue. Stdcall with 5 arguments.
proc queue_request
push ebx esi
virtual at esp
rd 2 ; saved registers
dd ? ; return address
.device dd ? ; pointer to usb_device_data
.ReqBuilder dd ? ; request_queue_item.ReqBuilder
.Buffer dd ? ; request_queue_item.Buffer
.Callback dd ? ; request_queue_item.Callback
.UserData dd ? ; request_queue_item.UserData
end virtual
; 1. Allocate the memory for the request description.
movi eax, request_queue_item.sizeof
call Kmalloc
test eax, eax
jnz @f
mov esi, nomemory
call SysMsgBoardStr
pop esi ebx
ret 20
@@:
; 2. Fill user-provided parts of the request description.
push edi
xchg eax, ebx
lea esi, [.ReqBuilder+4]
lea edi, [ebx+request_queue_item.ReqBuilder]
movsd ; ReqBuilder
movsd ; Buffer
movsd ; Callback
movsd ; UserData
pop edi
; 3. Set stage to zero: not started.
mov [ebx+request_queue_item.Stage], 0
; 4. Lock the queue.
mov esi, [.device]
lea ecx, [esi+usb_device_data.QueueLock]
call MutexLock
; 5. Insert the request to the tail of the queue.
add esi, usb_device_data.RequestsQueue
mov edx, [esi+request_queue_item.Prev]
mov [ebx+request_queue_item.Next], esi
mov [ebx+request_queue_item.Prev], edx
mov [edx+request_queue_item.Next], ebx
mov [esi+request_queue_item.Prev], ebx
; 6. Test whether the queue was empty
; and the request should be started immediately.
cmp [esi+request_queue_item.Next], ebx
jnz .unlock
; 8. If the step 6 shows that the request is the first in the queue,
; start it.
sub esi, usb_device_data.RequestsQueue
call setup_request
jmp .nothing
.unlock:
call MutexUnlock
; 9. Return.
.nothing:
pop esi ebx
ret 20
endp
; The current request is completed. Call the callback,
; remove the request from the queue, start the next
; request if there is one.
; esi points to usb_device_data
proc complete_request
; 1. Print common debug messages on fails.
if DEBUG
cmp [esi+usb_device_data.Status.Status], CSW_STATUS_FAIL
jb .normal
jz .fail
DEBUGF 1, 'K : Fatal error during execution of command %x\n', [esi+usb_device_data.Command.Command]:2
jmp .normal
.fail:
DEBUGF 1, 'K : Command %x failed\n', [esi+usb_device_data.Command.Command]:2
.normal:
end if
; 2. Get the current request.
mov ebx, [esi+usb_device_data.RequestsQueue+request_queue_item.Next]
; 3. Call the callback.
stdcall [ebx+request_queue_item.Callback], esi, [ebx+request_queue_item.UserData]
; 4. Lock the queue.
lea ecx, [esi+usb_device_data.QueueLock]
call MutexLock
; 5. Remove the request.
lea edx, [esi+usb_device_data.RequestsQueue]
mov eax, [ebx+request_queue_item.Next]
mov [eax+request_queue_item.Prev], edx
mov [edx+request_queue_item.Next], eax
; 6. Free the request memory.
push eax edx
xchg eax, ebx
call Kfree
pop edx ebx
; 7. If there is a next request, start processing.
cmp ebx, edx
jnz setup_request
; 8. Unlock the queue and return.
lea ecx, [esi+usb_device_data.QueueLock]
call MutexUnlock
ret
endp
; Start processing the request. Called either by queue_request
; or when the previous request has been processed.
; Do not call directly, use queue_request.
; Must be called when queue is locked; unlocks the queue when returns.
proc setup_request
xor eax, eax
; 1. If DeviceDisconnected has been run, then all handles of pipes
; are invalid, so we must fail immediately.
; (That is why this function needs the locked queue: this
; guarantee that either DeviceDisconnected has been already run, or
; DeviceDisconnected will not return before the queue is unlocked.)
cmp [esi+usb_device_data.DeviceDisconnected], al
jnz .fatal
; 2. If the previous command has encountered a fatal error,
; perform reset recovery.
cmp [esi+usb_device_data.Status.Status], CSW_STATUS_FATAL
jb .norecovery
; 2a. Send Bulk-Only Mass Storage Reset command to config pipe.
lea edx, [esi+usb_device_data.ConfigRequest]
mov word [edx], (REQUEST_BORESET shl 8) + 21h ; class request
mov word [edx+6], ax ; length = 0
stdcall USBControlTransferAsync, [esi+usb_device_data.ConfigPipe], edx, eax, eax, recovery_callback1, esi, eax
; 2b. Fail here = fatal error.
test eax, eax
jz .fatal
; 2c. Otherwise, unlock the queue and return. recovery_callback1 will continue processing.
.unlock_return:
lea ecx, [esi+usb_device_data.QueueLock]
call MutexUnlock
ret
.norecovery:
; 3. Send the command. Fail (no memory or device disconnected) = fatal error.
; Otherwise, go to 2c.
call request_stage1
test eax, eax
jnz .unlock_return
.fatal:
; 4. Fatal error. Set status = FATAL, unlock the queue, complete the request.
mov [esi+usb_device_data.Status.Status], CSW_STATUS_FATAL
lea ecx, [esi+usb_device_data.QueueLock]
call MutexUnlock
jmp complete_request
endp
; Initiate USB transfer for the first stage of a request (send command).
proc request_stage1
mov ebx, [esi+usb_device_data.RequestsQueue+request_queue_item.Next]
; 1. Set the stage to 1 = command stage.
inc [ebx+request_queue_item.Stage]
; 2. Generate the command. Zero-initialize and use the caller-provided proc.
lea edx, [esi+usb_device_data.Command]
xor eax, eax
mov [edx+command_block_wrapper.CommandLength], 12
mov dword [edx+command_block_wrapper.Command], eax
mov dword [edx+command_block_wrapper.Command+4], eax
mov dword [edx+command_block_wrapper.Command+8], eax
mov dword [edx+command_block_wrapper.Command+12], eax
inc [edx+command_block_wrapper.Tag]
stdcall [ebx+request_queue_item.ReqBuilder], edx, [ebx+request_queue_item.UserData]
; 4. Initiate USB transfer.
lea edx, [esi+usb_device_data.Command]
if DUMP_PACKETS
DEBUGF 1,'K : USBSTOR out:'
mov eax, edx
mov ecx, command_block_wrapper.sizeof
call debug_dump
DEBUGF 1,'\n'
end if
stdcall USBNormalTransferAsync, [esi+usb_device_data.OutPipe], edx, command_block_wrapper.sizeof, request_callback1, esi, 0
test eax, eax
jz .nothing
; 5. If the next stage is data stage in the same direction, enqueue it here.
cmp [esi+usb_device_data.Command.Flags], 0
js .nothing
cmp [esi+usb_device_data.Command.Length], 0
jz .nothing
mov edx, [esi+usb_device_data.RequestsQueue+request_queue_item.Next]
if DUMP_PACKETS
DEBUGF 1,'K : USBSTOR out:'
mov eax, [edx+request_queue_item.Buffer]
mov ecx, [esi+usb_device_data.Command.Length]
call debug_dump
DEBUGF 1,'\n'
end if
stdcall USBNormalTransferAsync, [esi+usb_device_data.OutPipe], [edx+request_queue_item.Buffer], [esi+usb_device_data.Command.Length], request_callback2, esi, 0
.nothing:
ret
endp
if DUMP_PACKETS
proc debug_dump
test ecx, ecx
jz .done
.loop:
test ecx, 0Fh
jnz @f
DEBUGF 1,'\nK :'
@@:
DEBUGF 1,' %x',[eax]:2
inc eax
dec ecx
jnz .loop
.done:
ret
endp
end if
; Called when the Reset command is completed,
; either successfully or not.
proc recovery_callback1
virtual at esp
dd ? ; return address
.pipe dd ?
.status dd ?
.buffer dd ?
.length dd ?
.calldata dd ?
end virtual
cmp [.status], 0
jnz .error
; todo: reset pipes
push ebx esi
mov esi, [.calldata+8]
call request_stage1
pop esi ebx
test eax, eax
jz .error
ret 20
.error:
DEBUGF 1, 'K : error %d while resetting', [.status]
jmp request_callback1.common_error
endp
; Called when the first stage of request is completed,
; either successfully or not.
proc request_callback1
virtual at esp
dd ? ; return address
.pipe dd ?
.status dd ?
.buffer dd ?
.length dd ?
.calldata dd ?
end virtual
; 1. Initialize.
mov ecx, [.calldata]
mov eax, [.status]
; 2. Test for error.
test eax, eax
jnz .error
; No error.
; 3. Increment the stage.
mov edx, [ecx+usb_device_data.RequestsQueue+request_queue_item.Next]
inc [edx+request_queue_item.Stage]
; 4. Check whether we need to send the data.
; 4a. If there is no data, skip this stage.
cmp [ecx+usb_device_data.Command.Length], 0
jz ..request_get_status
; 4b. If data were enqueued in the first stage, do nothing, wait for request_callback2.
cmp [ecx+usb_device_data.Command.Flags], 0
jns .nothing
; 5. Initiate USB transfer. If this fails, go to the error handler.
stdcall USBNormalTransferAsync, [ecx+usb_device_data.InPipe], [edx+request_queue_item.Buffer], [ecx+usb_device_data.Command.Length], request_callback2, ecx, 0
test eax, eax
jz .error
; 6. The status stage goes to the same direction, enqueue it now.
mov ecx, [.calldata]
jmp ..enqueue_status
.nothing:
ret 20
.error:
; Error.
; 7. Print debug message and complete the request as failed.
DEBUGF 1,'K : error %d after %d bytes in request stage\n',eax,[.length]
.common_error:
; TODO: add recovery after STALL
mov ecx, [.calldata]
mov [ecx+usb_device_data.Status.Status], CSW_STATUS_FATAL
push ebx esi
mov esi, ecx
call complete_request
pop esi ebx
ret 20
endp
; Called when the second stage of request is completed,
; either successfully or not.
proc request_callback2
virtual at esp
dd ? ; return address
.pipe dd ?
.status dd ?
.buffer dd ?
.length dd ?
.calldata dd ?
end virtual
if DUMP_PACKETS
mov eax, [.calldata]
mov eax, [eax+usb_device_data.InPipe]
cmp [.pipe], eax
jnz @f
DEBUGF 1,'K : USBSTOR in:'
push eax ecx
mov eax, [.buffer+8]
mov ecx, [.length+8]
call debug_dump
pop ecx eax
DEBUGF 1,'\n'
@@:
end if
; 1. Initialize.
mov ecx, [.calldata]
mov eax, [.status]
; 2. Test for error.
test eax, eax
jnz .error
; No error.
; If the previous stage was in same direction, do nothing; status request is already enqueued.
cmp [ecx+usb_device_data.Command.Flags], 0
js .nothing
..request_get_status:
; 3. Increment the stage.
mov edx, [ecx+usb_device_data.RequestsQueue+request_queue_item.Next]
inc [edx+request_queue_item.Stage]
; 4. Initiate USB transfer. If this fails, go to the error handler.
..enqueue_status:
lea edx, [ecx+usb_device_data.Status]
stdcall USBNormalTransferAsync, [ecx+usb_device_data.InPipe], edx, command_status_wrapper.sizeof, request_callback3, ecx, 0
test eax, eax
jz .error
.nothing:
ret 20
.error:
; Error.
; 7. Print debug message and complete the request as failed.
DEBUGF 1,'K : error %d after %d bytes in data stage\n',eax,[.length]
jmp request_callback1.common_error
endp
; Called when the third stage of request is completed,
; either successfully or not.
proc request_callback3
virtual at esp
dd ? ; return address
.pipe dd ?
.status dd ?
.buffer dd ?
.length dd ?
.calldata dd ?
end virtual
if DUMP_PACKETS
DEBUGF 1,'K : USBSTOR in:'
mov eax, [.buffer]
mov ecx, [.length]
call debug_dump
DEBUGF 1,'\n'
end if
; 1. Initialize.
mov eax, [.status]
; 2. Test for error.
test eax, eax
jnz .transfer_error
; Transfer is OK.
; 3. Validate the status. Invalid status = fatal error.
push ebx esi
mov esi, [.calldata+8]
mov ebx, [esi+usb_device_data.RequestsQueue+request_queue_item.Next]
cmp [esi+usb_device_data.Status.Signature], 'USBS'
jnz .invalid
mov eax, [esi+usb_device_data.Command.Tag]
cmp [esi+usb_device_data.Status.Tag], eax
jnz .invalid
cmp [esi+usb_device_data.Status.Status], CSW_STATUS_FATAL
ja .invalid
; 4. The status block is valid. Check the status code.
jz .complete
; 5. If this command was not REQUEST_SENSE, copy status data to safe place.
; Otherwise, the original command has failed, so restore the fail status.
cmp byte [esi+usb_device_data.Command.Command], SCSI_REQUEST_SENSE
jz .request_sense
mov eax, [esi+usb_device_data.Status.LengthRest]
mov [esi+usb_device_data.LengthRest], eax
cmp [esi+usb_device_data.Status.Status], CSW_STATUS_FAIL
jz .fail
.complete:
call complete_request
.nothing:
pop esi ebx
ret 20
.request_sense:
mov [esi+usb_device_data.Status.Status], CSW_STATUS_FAIL
jmp .complete
.invalid:
; 6. Invalid status block. Say error, set status to fatal and complete request.
push esi
mov esi, invresponse
call SysMsgBoardStr
pop esi
mov [esi+usb_device_data.Status.Status], CSW_STATUS_FATAL
jmp .complete
.fail:
; 7. The command has failed.
; If this command was not REQUEST_SENSE, schedule the REQUEST_SENSE command
; to determine the reason of fail. Otherwise, assume that there is no error data.
cmp [esi+usb_device_data.Command.Command], SCSI_REQUEST_SENSE
jz .fail_request_sense
mov [ebx+request_queue_item.ReqBuilder], request_sense_req
lea eax, [esi+usb_device_data.Sense]
mov [ebx+request_queue_item.Buffer], eax
call request_stage1
test eax, eax
jnz .nothing
.fail_request_sense:
DEBUGF 1,'K : fail during REQUEST SENSE\n'
mov byte [esi+usb_device_data.Sense], 0
jmp .complete
.transfer_error:
; TODO: add recovery after STALL
DEBUGF 1,'K : error %d after %d bytes in status stage\n',eax,[.length]
jmp request_callback1.common_error
endp
; Builder for SCSI_REQUEST_SENSE request.
; edx = first argument = pointer to usb_device_data.Command,
; second argument = custom data given to queue_request (ignored).
proc request_sense_req
mov [edx+command_block_wrapper.Length], sense_data.sizeof
mov [edx+command_block_wrapper.Flags], CBW_FLAG_IN
mov byte [edx+command_block_wrapper.Command+0], SCSI_REQUEST_SENSE
mov byte [edx+command_block_wrapper.Command+4], sense_data.sizeof
ret 8
endp
; This procedure is called when new mass-storage device is detected.
; It initializes the device.
; Technically, initialization implies sending several USB queries,
; so it is split in several procedures. The first is AddDevice,
; other are callbacks which will be called at some time in the future,
; when the device will respond.
; The general scheme:
; * AddDevice parses descriptors, opens pipes; if everything is ok,
; AddDevice sends REQUEST_GETMAXLUN with callback known_lun_callback;
; * known_lun_callback allocates memory for LogicalDevices and sends
; SCSI_TEST_UNIT_READY to all logical devices with test_unit_ready_callback;
; * test_unit_ready_callback checks whether the unit is ready;
; if not, it repeats the same request several times;
; if ok or there were too many attempts, it sends SCSI_INQUIRY with
; callback inquiry_callback;
; * inquiry_callback checks that a logical device is a block device
; and the unit was ready; if so, it notifies the kernel about new disk device.
proc AddDevice
push ebx esi
virtual at esp
rd 2 ; saved registers ebx, esi
dd ? ; return address
.pipe0 dd ? ; handle of the config pipe
.config dd ? ; pointer to config_descr
.interface dd ? ; pointer to interface_descr
end virtual
; 1. Check device type. Currently only SCSI-command-set Bulk-only devices
; are supported.
; 1a. Get the subclass and the protocol. Since bInterfaceSubClass and
; bInterfaceProtocol are subsequent in interface_descr, just one
; memory reference is used for both.
mov esi, [.interface]
xor ebx, ebx
mov cx, word [esi+interface_descr.bInterfaceSubClass]
; 1b. For Mass-storage SCSI-command-set Bulk-only devices subclass must be 6
; and protocol must be 50h. Check.
cmp cx, 0x5006
jz .known
; There are devices with subclass 5 which use the same protocol 50h.
; The difference is not important for the code except for this test,
; so allow them to proceed also.
cmp cx, 0x5005
jz .known
; 1c. If the device is unknown, print a message and go to 11c.
mov esi, unkdevice
call SysMsgBoardStr
jmp .nothing
; 1d. If the device uses known command set, print a message and continue
; configuring.
.known:
push esi
mov esi, okdevice
call SysMsgBoardStr
pop esi
; 2. Allocate memory for internal device data.
; 2a. Call the kernel.
mov eax, usb_device_data.sizeof
call Kmalloc
; 2b. Check return value.
test eax, eax
jnz @f
; 2c. If failed, say a message and go to 11c.
mov esi, nomemory
call SysMsgBoardStr
jmp .nothing
@@:
; 2d. If succeeded, zero the contents and continue configuring.
xchg ebx, eax ; ebx will point to usb_device_data
xor eax, eax
mov [ebx+usb_device_data.OutPipe], eax
mov [ebx+usb_device_data.InPipe], eax
mov [ebx+usb_device_data.MaxLUN], eax
mov [ebx+usb_device_data.LogicalDevices], eax
mov dword [ebx+usb_device_data.ConfigRequest], eax
mov dword [ebx+usb_device_data.ConfigRequest+4], eax
mov [ebx+usb_device_data.Status.Status], al
mov [ebx+usb_device_data.DeviceDisconnected], al
; 2e. There is one reference: a connected USB device.
inc eax
mov [ebx+usb_device_data.NumReferences], eax
; 2f. Save handle of configuration pipe for reset recovery.
mov eax, [.pipe0]
mov [ebx+usb_device_data.ConfigPipe], eax
; 2g. Save the interface number for configuration requests.
mov al, [esi+interface_descr.bInterfaceNumber]
mov [ebx+usb_device_data.ConfigRequest+4], al
; 2h. Initialize common fields in command wrapper.
mov [ebx+usb_device_data.Command.Signature], 'USBC'
mov [ebx+usb_device_data.Command.Tag], 'xxxx'
; 2i. Initialize requests queue.
lea eax, [ebx+usb_device_data.RequestsQueue]
mov [eax+request_queue_item.Next], eax
mov [eax+request_queue_item.Prev], eax
lea ecx, [ebx+usb_device_data.QueueLock]
call MutexInit
; Bulk-only mass storage devices use one OUT bulk endpoint for sending
; command/data and one IN bulk endpoint for receiving data/status.
; Look for those endpoints.
; 3. Get the upper bound of all descriptors' data.
mov edx, [.config] ; configuration descriptor
movzx ecx, [edx+config_descr.wTotalLength]
add edx, ecx
; 4. Loop over all descriptors until
; either end-of-data reached - this is fail
; or interface descriptor found - this is fail, all further data
; correspond to that interface
; or both endpoint descriptors found.
; 4a. Loop start: esi points to the interface descriptor,
.lookep:
; 4b. Get next descriptor.
movzx ecx, byte [esi] ; the first byte of all descriptors is length
add esi, ecx
; 4c. Check that at least two bytes are readable. The opposite is an error.
inc esi
cmp esi, edx
jae .errorep
dec esi
; 4d. Check that this descriptor is not interface descriptor. The opposite is
; an error.
cmp byte [esi+endpoint_descr.bDescriptorType], INTERFACE_DESCR_TYPE
jz .errorep
; 4e. Test whether this descriptor is an endpoint descriptor. If not, continue
; the loop.
cmp byte [esi+endpoint_descr.bDescriptorType], ENDPOINT_DESCR_TYPE
jnz .lookep
; 5. Check that the descriptor contains all required data and all data are
; readable. The opposite is an error.
cmp byte [esi+endpoint_descr.bLength], endpoint_descr.sizeof
jb .errorep
lea ecx, [esi+endpoint_descr.sizeof]
cmp ecx, edx
ja .errorep
; 6. Check that the endpoint is bulk endpoint. The opposite is an error.
mov cl, [esi+endpoint_descr.bmAttributes]
and cl, 3
cmp cl, BULK_PIPE
jnz .errorep
; 7. Get the direction of this endpoint.
movzx ecx, [esi+endpoint_descr.bEndpointAddress]
shr ecx, 7
; 8. Test whether a pipe for this direction is already opened. If so, continue
; the loop.
cmp [ebx+usb_device_data.OutPipe+ecx*4], 0
jnz .lookep
; 9. Open pipe for this endpoint.
; 9a. Save registers.
push ecx edx
; 9b. Load parameters from the descriptor.
movzx ecx, [esi+endpoint_descr.bEndpointAddress]
movzx edx, [esi+endpoint_descr.wMaxPacketSize]
movzx eax, [esi+endpoint_descr.bInterval] ; not used for USB1, may be important for USB2
; 9c. Call the kernel.
stdcall USBOpenPipe, [ebx+usb_device_data.ConfigPipe], ecx, edx, BULK_PIPE, eax
; 9d. Restore registers.
pop edx ecx
; 9e. Check result. If failed, go to 11b.
test eax, eax
jz .free
; 9f. Save result.
mov [ebx+usb_device_data.OutPipe+ecx*4], eax
; 10. Test whether the second pipe is already opened. If not, continue loop.
xor ecx, 1
cmp [ebx+usb_device_data.OutPipe+ecx*4], 0
jz .lookep
jmp .created
; 11. An error occured during processing endpoint descriptor.
.errorep:
; 11a. Print a message.
DEBUGF 1,'K : error: invalid endpoint descriptor\n'
.free:
; 11b. Free the allocated usb_device_data.
xchg eax, ebx
call Kfree
.nothing:
; 11c. Return an error.
xor eax, eax
jmp .return
.created:
; 12. Pipes are opened. Send GetMaxLUN control request.
lea eax, [ebx+usb_device_data.ConfigRequest]
mov byte [eax], 0A1h ; class request from interface
mov byte [eax+1], REQUEST_GETMAXLUN
mov byte [eax+6], 1 ; transfer 1 byte
lea ecx, [ebx+usb_device_data.MaxLUN]
if DUMP_PACKETS
DEBUGF 1,'K : GETMAXLUN: %x %x %x %x %x %x %x %x\n',[eax]:2,[eax+1]:2,[eax+2]:2,[eax+3]:2,[eax+4]:2,[eax+5]:2,[eax+6]:2,[eax+7]:2
end if
stdcall USBControlTransferAsync, [ebx+usb_device_data.ConfigPipe], eax, ecx, 1, known_lun_callback, ebx, 0
; 13. Return with pointer to device data as returned value.
xchg eax, ebx
.return:
pop esi ebx
ret 12
endp
; This function is called when REQUEST_GETMAXLUN is done,
; either successful or unsuccessful.
proc known_lun_callback
push ebx esi
virtual at esp
rd 2 ; saved registers
dd ? ; return address
.pipe dd ?
.status dd ?
.buffer dd ?
.length dd ?
.calldata dd ?
end virtual
; 1. Check the status. If the request failed, assume that MaxLUN is zero.
mov ebx, [.calldata]
mov eax, [.status]
test eax, eax
jz @f
DEBUGF 1, 'K : GETMAXLUN failed with status %d, assuming zero\n', eax
mov [ebx+usb_device_data.MaxLUN], 0
@@:
; 2. Allocate the memory for logical devices.
mov eax, [ebx+usb_device_data.MaxLUN]
inc eax
DEBUGF 1,'K : %d logical unit(s)\n',eax
imul eax, usb_unit_data.sizeof
push ebx
call Kmalloc
pop ebx
; If failed, print a message and do nothing.
test eax, eax
jnz @f
mov esi, nomemory
call SysMsgBoardStr
pop esi ebx
ret 20
@@:
mov [ebx+usb_device_data.LogicalDevices], eax
; 3. Initialize logical devices and initiate TEST_UNIT_READY request.
xchg esi, eax
xor ecx, ecx
.looplun:
mov [esi+usb_unit_data.Parent], ebx
mov [esi+usb_unit_data.LUN], cl
xor eax, eax
mov [esi+usb_unit_data.MediaPresent], al
mov [esi+usb_unit_data.DiskDevice], eax
mov [esi+usb_unit_data.SectorSize], eax
mov [esi+usb_unit_data.UnitReadyAttempts], eax
push ecx
call GetTimerTicks
mov [esi+usb_unit_data.TimerTicks], eax
stdcall queue_request, ebx, test_unit_ready_req, 0, test_unit_ready_callback, esi
pop ecx
inc ecx
add esi, usb_unit_data.sizeof
cmp ecx, [ebx+usb_device_data.MaxLUN]
jbe .looplun
; 4. Return.
pop esi ebx
ret 20
endp
; Builder for SCSI INQUIRY request.
; edx = first argument = pointer to usb_device_data.Command,
; second argument = custom data given to queue_request.
proc inquiry_req
mov eax, [esp+8]
mov al, [eax+usb_unit_data.LUN]
mov [edx+command_block_wrapper.Length], inquiry_data.sizeof
mov [edx+command_block_wrapper.Flags], CBW_FLAG_IN
mov [edx+command_block_wrapper.LUN], al
mov byte [edx+command_block_wrapper.Command+0], SCSI_INQUIRY
mov byte [edx+command_block_wrapper.Command+4], inquiry_data.sizeof
ret 8
endp
; Called when SCSI INQUIRY request is completed.
proc inquiry_callback
; 1. Check the status.
mov ecx, [esp+4]
cmp [ecx+usb_device_data.Status.Status], CSW_STATUS_OK
jnz .fail
; 2. The command has completed successfully.
; Print a message showing device type, ignore anything but block devices.
mov al, [ecx+usb_device_data.InquiryData.PeripheralDevice]
and al, 1Fh
DEBUGF 1,'K : peripheral device type is %x\n',al
test al, al
jnz .nothing
DEBUGF 1,'K : direct-access mass storage device detected\n'
; 3. We have found a new disk device. Increment number of references.
lock inc [ecx+usb_device_data.NumReferences]
; Unfortunately, we are now in the context of the USB thread,
; so we can't notify the kernel immediately: it would try to do something
; with a new disk, those actions would be synchronous and would require
; waiting for results of USB requests, but we need to exit this callback
; to allow the USB thread to continue working and handling those requests.
; 4. Thus, create a temporary kernel thread which would do it.
mov edx, [esp+8]
push ebx ecx esi edi
movi ebx, 1
mov ecx, new_disk_thread
; edx = parameter
call CreateThread
pop edi esi ecx ebx
cmp eax, -1
jnz .nothing
; on error, reverse step 3
lock dec [ecx+usb_device_data.NumReferences]
.nothing:
ret 8
.fail:
; 4. The command has failed. Print a message and do nothing.
push esi
mov esi, inquiry_fail
call SysMsgBoardStr
pop esi
ret 8
endp
; Builder for SCSI TEST_UNIT_READY request.
; edx = first argument = pointer to usb_device_data.Command,
; second argument = custom data given to queue_request.
proc test_unit_ready_req
mov eax, [esp+8]
mov al, [eax+usb_unit_data.LUN]
mov [edx+command_block_wrapper.Length], 0
mov [edx+command_block_wrapper.Flags], CBW_FLAG_IN
mov [edx+command_block_wrapper.LUN], al
ret 8
endp
; Called when SCSI TEST_UNIT_READY request is completed.
proc test_unit_ready_callback
virtual at esp
dd ? ; return address
.device dd ?
.calldata dd ?
end virtual
; 1. Check the status.
mov ecx, [.device]
mov edx, [.calldata]
cmp [ecx+usb_device_data.Status.Status], CSW_STATUS_OK
jnz .fail
; 2. The command has completed successfully,
; possibly after some repetitions. Print a debug message showing
; number and time of those. Remember that media is ready and go to 4.
DEBUGF 1,'K : media is ready\n'
call GetTimerTicks
sub eax, [edx+usb_unit_data.TimerTicks]
DEBUGF 1,'K : %d attempts, %d ticks\n',[edx+usb_unit_data.UnitReadyAttempts],eax
inc [edx+usb_unit_data.MediaPresent]
jmp .inquiry
.fail:
; 3. The command has failed.
; Retry the same request up to 3 times with 10ms delay;
; if limit of retries is not reached, exit from the function.
; Otherwise, go to 4.
inc [edx+usb_unit_data.UnitReadyAttempts]
cmp [edx+usb_unit_data.UnitReadyAttempts], 3
jz @f
push ecx edx esi
movi esi, 10
call Sleep
pop esi edx ecx
stdcall queue_request, ecx, test_unit_ready_req, 0, test_unit_ready_callback, edx
ret 8
@@:
DEBUGF 1,'K : media not ready\n'
.inquiry:
; 4. initiate INQUIRY request.
lea eax, [ecx+usb_device_data.InquiryData]
stdcall queue_request, ecx, inquiry_req, eax, inquiry_callback, edx
ret 8
endp
; Temporary thread for initial actions with a new disk device.
proc new_disk_thread
sub esp, 32
virtual at esp
.name rb 32 ; device name
.param dd ? ; contents of edx at the moment of int 0x40/eax=51
dd ? ; stack segment
end virtual
; We are ready to notify the kernel about a new disk device.
mov esi, [.param]
; 1. Generate name.
; 1a. Find a free index.
mov ecx, free_numbers_lock
call MutexLock
xor eax, eax
@@:
bsf edx, [free_numbers+eax]
jnz @f
add eax, 4
cmp eax, 4*4
jnz @b
call MutexUnlock
push esi
mov esi, noindex
call SysMsgBoardStr
pop esi
jmp .drop_reference
@@:
; 1b. Mark the index as busy.
btr [free_numbers+eax], edx
lea eax, [eax*8+edx]
push eax
call MutexUnlock
pop eax
; 1c. Generate a name of the form "usbhd<index>" in the stack.
mov dword [esp], 'usbh'
lea edi, [esp+5]
mov byte [edi-1], 'd'
push eax
push -'0'
movi ecx, 10
@@:
cdq
div ecx
push edx
test eax, eax
jnz @b
@@:
pop eax
add al, '0'
stosb
jnz @b
pop ecx
mov edx, esp
; 3d. Store the index in usb_unit_data to free it later.
mov [esi+usb_unit_data.DiskIndex], cl
; 4. Notify the kernel about a new disk.
; 4a. Add a disk.
; stdcall queue_request, ecx, read_capacity_req, eax, read_capacity_callback, eax
stdcall DiskAdd, disk_functions, edx, esi, 0
mov ebx, eax
; 4b. If it failed, release the index and do nothing.
test eax, eax
jz .free_index
; 4c. Notify the kernel that a media is present.
stdcall DiskMediaChanged, eax, 1
; 5. Lock the requests queue, check that device is not disconnected,
; store the disk handle, unlock the requests queue.
mov ecx, [esi+usb_unit_data.Parent]
add ecx, usb_device_data.QueueLock
call MutexLock
cmp byte [ecx+usb_device_data.DeviceDisconnected-usb_device_data.QueueLock], 0
jnz .disconnected
mov [esi+usb_unit_data.DiskDevice], ebx
call MutexUnlock
jmp .exit
.disconnected:
call MutexUnlock
stdcall disk_close, ebx
jmp .exit
.free_index:
mov ecx, free_numbers_lock
call MutexLock
movzx eax, [esi+usb_unit_data.DiskIndex]
bts [free_numbers], eax
call MutexUnlock
.drop_reference:
mov esi, [esi+usb_unit_data.Parent]
lock dec [esi+usb_device_data.NumReferences]
jnz .exit
mov eax, [esi+usb_device_data.LogicalDevices]
call Kfree
xchg eax, esi
call Kfree
.exit:
or eax, -1
int 0x40
endp
; This function is called when the device is disconnected.
proc DeviceDisconnected
push ebx esi
virtual at esp
rd 2 ; saved registers
dd ? ; return address
.device dd ?
end virtual
; 1. Say a message.
mov esi, disconnectmsg
call SysMsgBoardStr
; 2. Lock the requests queue, set .DeviceDisconnected to 1,
; unlock the requests queue.
; Locking is required for synchronization with queue_request:
; all USB callbacks are executed in the same thread and are
; synchronized automatically, but queue_request can be running
; from any thread which wants to do something with a filesystem.
; Without locking, it would be possible that queue_request has
; been started, has checked that device is not yet disconnected,
; then DeviceDisconnected completes and all handles become invalid,
; then queue_request tries to use them.
mov esi, [.device]
lea ecx, [esi+usb_device_data.QueueLock]
call MutexLock
mov [esi+usb_device_data.DeviceDisconnected], 1
call MutexUnlock
; 3. Drop one reference to the structure and check whether
; that was the last reference.
lock dec [esi+usb_device_data.NumReferences]
jz .free
; 4. If not, there are some additional references due to disk devices;
; notify the kernel that those disks are deleted.
; Note that new disks cannot be added while we are looping here,
; because new_disk_thread checks for .DeviceDisconnected.
mov ebx, [esi+usb_device_data.MaxLUN]
mov esi, [esi+usb_device_data.LogicalDevices]
inc ebx
.diskdel:
mov eax, [esi+usb_unit_data.DiskDevice]
test eax, eax
jz @f
stdcall DiskDel, eax
@@:
add esi, usb_unit_data.sizeof
dec ebx
jnz .diskdel
; In this case, some operations with those disks are still possible,
; so we can't do anything more now. disk_close will take care of the rest.
.return:
pop esi ebx
ret 4
; 5. If there are no disk devices, free all resources which were allocated.
.free:
mov eax, [esi+usb_device_data.LogicalDevices]
test eax, eax
jz @f
call Kfree
@@:
xchg eax, esi
call Kfree
jmp .return
endp
; Disk functions.
DISK_STATUS_OK = 0 ; success
DISK_STATUS_GENERAL_ERROR = -1; if no other code is suitable
DISK_STATUS_INVALID_CALL = 1 ; invalid input parameters
DISK_STATUS_NO_MEDIA = 2 ; no media present
DISK_STATUS_END_OF_MEDIA = 3 ; end of media while reading/writing data
; Called when all operations with the given disk are done.
proc disk_close
push ebx esi
virtual at esp
rd 2 ; saved registers
dd ? ; return address
.userdata dd ?
end virtual
mov esi, [.userdata]
mov ecx, free_numbers_lock
call MutexLock
movzx eax, [esi+usb_unit_data.DiskIndex]
bts [free_numbers], eax
call MutexUnlock
mov esi, [esi+usb_unit_data.Parent]
lock dec [esi+usb_device_data.NumReferences]
jnz .nothing
mov eax, [esi+usb_device_data.LogicalDevices]
call Kfree
xchg eax, esi
call Kfree
.nothing:
pop esi ebx
ret 4
endp
; Returns sector size, capacity and flags of the media.
proc disk_querymedia stdcall uses ebx esi edi, \
userdata:dword, mediainfo:dword
; 1. Create event for waiting.
xor esi, esi
xor ecx, ecx
call CreateEvent
test eax, eax
jz .generic_fail
push eax
push edx
push ecx
push 0
push 0
virtual at ebp-.localsize
.locals:
; two following dwords are the output of READ_CAPACITY
.LastLBABE dd ?
.SectorSizeBE dd ?
.Status dd ?
; two following dwords identify an event
.event_code dd ?
.event dd ?
rd 3 ; saved registers
.localsize = $ - .locals
dd ? ; saved ebp
dd ? ; return address
.userdata dd ?
.mediainfo dd ?
end virtual
; 2. Initiate SCSI READ_CAPACITY request.
mov eax, [userdata]
mov ecx, [eax+usb_unit_data.Parent]
mov edx, esp
stdcall queue_request, ecx, read_capacity_req, edx, read_capacity_callback, edx
; 3. Wait for event. This destroys it.
mov eax, [.event]
mov ebx, [.event_code]
call WaitEvent
; 4. Get the status and results.
pop ecx
bswap ecx ; .LastLBA
pop edx
bswap edx ; .SectorSize
pop eax ; .Status
; 5. If the request has completed successfully, store results.
test eax, eax
jnz @f
DEBUGF 1,'K : sector size is %d, last sector is %d\n',edx,ecx
mov ebx, [mediainfo]
mov [ebx], eax ; flags = 0
mov [ebx+4], edx ; sectorsize
add ecx, 1
adc eax, 0
mov [ebx+8], ecx
mov [ebx+12], eax ; capacity
mov eax, [userdata]
mov [eax+usb_unit_data.SectorSize], edx
xor eax, eax
@@:
; 6. Restore the stack and return.
pop ecx
pop ecx
ret
.generic_fail:
or eax, -1
ret
endp
; Builder for SCSI READ_CAPACITY request.
; edx = first argument = pointer to usb_device_data.Command,
; second argument = custom data given to queue_request,
; pointer to disk_querymedia.locals.
proc read_capacity_req
mov eax, [esp+8]
mov eax, [eax+disk_querymedia.userdata-disk_querymedia.locals]
mov al, [eax+usb_unit_data.LUN]
mov [edx+command_block_wrapper.Length], 8
mov [edx+command_block_wrapper.Flags], CBW_FLAG_IN
mov [edx+command_block_wrapper.LUN], al
mov byte [edx+command_block_wrapper.Command+0], SCSI_READ_CAPACITY
ret 8
endp
; Called when SCSI READ_CAPACITY request is completed.
proc read_capacity_callback
; Transform the status to return value of disk_querymedia
; and set the event.
mov ecx, [esp+4]
xor eax, eax
cmp [ecx+usb_device_data.Status.Status], al
jz @f
or eax, -1
@@:
mov ecx, [esp+8]
mov [ecx+disk_querymedia.Status-disk_querymedia.locals], eax
push ebx esi edi
mov eax, [ecx+disk_querymedia.event-disk_querymedia.locals]
mov ebx, [ecx+disk_querymedia.event_code-disk_querymedia.locals]
xor edx, edx
xor esi, esi
call RaiseEvent
pop edi esi ebx
ret 8
endp
disk_write:
mov al, SCSI_WRITE10
jmp disk_read_write
disk_read:
mov al, SCSI_READ10
; Reads from the device or writes to the device.
proc disk_read_write stdcall uses ebx esi edi, \
userdata:dword, buffer:dword, startsector:qword, numsectors:dword
; 1. Initialize.
push eax ; .command
mov eax, [userdata]
mov eax, [eax+usb_unit_data.SectorSize]
push eax ; .SectorSize
push 0 ; .processed
mov eax, [numsectors]
mov eax, [eax]
; 2. The transfer length for SCSI_{READ,WRITE}10 commands can not be greater
; than 0xFFFF, so split the request to slices with <= 0xFFFF sectors.
max_sectors_at_time = 0xFFFF
.split:
push eax ; .length_rest
cmp eax, max_sectors_at_time
jb @f
mov eax, max_sectors_at_time
@@:
sub [esp], eax
push eax ; .length_cur
; 3. startsector must fit in 32 bits, otherwise abort the request.
cmp dword [startsector+4], 0
jnz .generic_fail
; 4. Create event for waiting.
xor esi, esi
xor ecx, ecx
call CreateEvent
test eax, eax
jz .generic_fail
push eax ; .event
push edx ; .event_code
push ecx ; .status
virtual at ebp-.localsize
.locals:
.status dd ?
.event_code dd ?
.event dd ?
.length_cur dd ?
.length_rest dd ?
.processed dd ?
.SectorSize dd ?
.command db ?
rb 3
rd 3 ; saved registers
.localsize = $ - .locals
dd ? ; saved ebp
dd ? ; return address
.userdata dd ?
.buffer dd ?
.startsector dq ?
.numsectors dd ?
end virtual
; 5. Initiate SCSI READ10 or WRITE10 request.
mov eax, [userdata]
mov ecx, [eax+usb_unit_data.Parent]
stdcall queue_request, ecx, read_write_req, [buffer], read_write_callback, esp
; 6. Wait for event. This destroys it.
mov eax, [.event]
mov ebx, [.event_code]
call WaitEvent
; 7. Get the status. If the operation has failed, abort.
pop eax ; .status
pop ecx ecx ; cleanup .event_code, .event
pop ecx ; .length_cur
test eax, eax
jnz .return
; 8. Otherwise, continue the loop started at step 2.
add dword [startsector], ecx
adc dword [startsector+4], eax
imul ecx, [.SectorSize]
add [buffer], ecx
pop eax
test eax, eax
jnz .split
push eax
.return:
; 9. Restore the stack, store .processed to [numsectors], return.
pop ecx ; .length_rest
pop ecx ; .processed
mov edx, [numsectors]
mov [edx], ecx
pop ecx ; .SectorSize
pop ecx ; .command
ret
.generic_fail:
or eax, -1
pop ecx ; .length_cur
jmp .return
endp
; Builder for SCSI READ10 or WRITE10 request.
; edx = first argument = pointer to usb_device_data.Command,
; second argument = custom data given to queue_request,
; pointer to disk_read_write.locals.
proc read_write_req
mov eax, [esp+8]
mov ecx, [eax+disk_read_write.userdata-disk_read_write.locals]
mov cl, [ecx+usb_unit_data.LUN]
mov [edx+command_block_wrapper.LUN], cl
mov ecx, [eax+disk_read_write.length_cur-disk_read_write.locals]
imul ecx, [eax+disk_read_write.SectorSize-disk_read_write.locals]
mov [edx+command_block_wrapper.Length], ecx
mov cl, [eax+disk_read_write.command-disk_read_write.locals]
mov [edx+command_block_wrapper.Flags], CBW_FLAG_OUT
cmp cl, SCSI_READ10
jnz @f
mov [edx+command_block_wrapper.Flags], CBW_FLAG_IN
@@:
mov byte [edx+command_block_wrapper.Command], cl
mov ecx, dword [eax+disk_read_write.startsector-disk_read_write.locals]
bswap ecx
mov dword [edx+command_block_wrapper.Command+2], ecx
mov ecx, [eax+disk_read_write.length_cur-disk_read_write.locals]
xchg cl, ch
mov word [edx+command_block_wrapper.Command+7], cx
ret 8
endp
; Called when SCSI READ10 or WRITE10 request is completed.
proc read_write_callback
; 1. Initialize.
push ebx esi edi
virtual at esp
rd 3 ; saved registers
dd ? ; return address
.device dd ?
.calldata dd ?
end virtual
mov ecx, [.device]
mov esi, [.calldata]
; 2. Get the number of sectors which were read.
; If the status is OK or FAIL, the field .LengthRest is valid.
; Otherwise, it is invalid, so assume zero sectors.
xor eax, eax
cmp [ecx+usb_device_data.Status.Status], CSW_STATUS_FAIL
ja .sectors_calculated
mov eax, [ecx+usb_device_data.LengthRest]
xor edx, edx
div [esi+disk_read_write.SectorSize-disk_read_write.locals]
test edx, edx
jz @f
inc eax
@@:
mov edx, eax
mov eax, [esi+disk_read_write.length_cur-disk_read_write.locals]
sub eax, edx
jae .sectors_calculated
xor eax, eax
.sectors_calculated:
; 3. Increase the total number of processed sectors.
add [esi+disk_read_write.processed-disk_read_write.locals], eax
; 4. Set status to OK if all sectors were read, to ERROR otherwise.
cmp eax, [esi+disk_read_write.length_cur-disk_read_write.locals]
setz al
movzx eax, al
dec eax
mov [esi+disk_read_write.status-disk_read_write.locals], eax
; 5. Set the event.
mov eax, [esi+disk_read_write.event-disk_read_write.locals]
mov ebx, [esi+disk_read_write.event_code-disk_read_write.locals]
xor edx, edx
xor esi, esi
call RaiseEvent
; 6. Return.
pop edi esi ebx
ret 8
endp
; strings
my_driver db 'usbstor',0
disconnectmsg db 'K : USB mass storage device disconnected',13,10,0
nomemory db 'K : no memory',13,10,0
unkdevice db 'K : unknown mass storage device',13,10,0
okdevice db 'K : USB mass storage device detected',13,10,0
transfererror db 'K : USB transfer error, disabling mass storage',13,10,0
invresponse db 'K : invalid response from mass storage device',13,10,0
fatalerr db 'K : mass storage device reports fatal error',13,10,0
inquiry_fail db 'K : INQUIRY command failed',13,10,0
;read_capacity_fail db 'K : READ CAPACITY command failed',13,10,0
;read_fail db 'K : READ command failed',13,10,0
noindex db 'K : failed to generate disk name',13,10,0
; Exported variable: kernel API version.
align 4
version dd 50005h
; Structure with callback functions.
usb_functions:
dd usb_functions_end - usb_functions
dd AddDevice
dd DeviceDisconnected
usb_functions_end:
disk_functions:
dd disk_functions_end - disk_functions
dd disk_close
dd 0 ; closemedia
dd disk_querymedia
dd disk_read
dd disk_write
dd 0 ; flush
dd 0 ; adjust_cache_size: use default cache
disk_functions_end:
free_numbers_lock rd 3
; 128 devices should be enough for everybody
free_numbers dd -1, -1, -1, -1
; for DEBUGF macro
include_debug_strings
; for uninitialized data
section '.data' data readable writable align 16
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