From e0cb5d4d0de752f2bf08ad3070e93a522d068949 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Klaus=20K=C3=A4mpf?= <kkaempf@gmail.com>
Date: Tue, 26 Dec 2023 16:54:24 +0100
Subject: [PATCH] Implement ModeSelect for scsicd
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and honor sector size setting.

DEC's VMS can't handle 2k sector sizes and uses ModeSelect6 to set the
sector size to 512 bytes.

Fixes #1397

Signed-off-by: Klaus Kämpf <kkaempf@gmail.com>
---
 cpp/devices/scsicd.cpp | 19 +++++++++++++++++++
 cpp/devices/scsicd.h   |  1 +
 2 files changed, 20 insertions(+)

diff --git a/cpp/devices/scsicd.cpp b/cpp/devices/scsicd.cpp
index 27ab23a3..a354a6fe 100644
--- a/cpp/devices/scsicd.cpp
+++ b/cpp/devices/scsicd.cpp
@@ -165,6 +165,25 @@ vector<uint8_t> SCSICD::InquiryInternal() const
 	return HandleInquiry(device_type::cd_rom, scsi_level, true);
 }
 
+void SCSICD::ModeSelect(scsi_command cmd, cdb_t cdb, span<const uint8_t> buf, int length)
+{
+	int sector_size = 1 << GetSectorSizeShiftCount();
+	int wanted_sector_size;
+	// skip Block Descriptor
+	int offset = 4;
+	// evaluate Mode Parameter Block Descriptor, sector size
+	wanted_sector_size = scsi_command_util::GetInt16(buf, offset + 6);
+	if (wanted_sector_size != sector_size) {
+		LogDebug("Changing sector size from " + to_string(sector_size) + " to " + to_string(wanted_sector_size));
+		SetSectorSizeInBytes(wanted_sector_size);
+	}
+
+	if (const string result = scsi_command_util::ModeSelect(cmd, cdb, buf, length, sector_size);
+		!result.empty()) {
+		LogWarn(result);
+	}
+}
+
 void SCSICD::SetUpModePages(map<int, vector<byte>>& pages, int page, bool changeable) const
 {
 	Disk::SetUpModePages(pages, page, changeable);
diff --git a/cpp/devices/scsicd.h b/cpp/devices/scsicd.h
index c2aaf4e3..cb1158dd 100644
--- a/cpp/devices/scsicd.h
+++ b/cpp/devices/scsicd.h
@@ -34,6 +34,7 @@ public:
 
 	vector<uint8_t> InquiryInternal() const override;
 	int Read(span<uint8_t>, uint64_t) override;
+	void ModeSelect(scsi_defs::scsi_command, cdb_t, span<const uint8_t>, int) override;
 
 protected: