70004 & 70046: added friday ADSD lecture and advanced security

OliverKillane · Jan 19, 2024 · 5962a8a · 5962a8a
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diff --git a/70004 - Advanced Computer Security/1975 Design Principles.md b/70004 - Advanced Computer Security/1975 Design Principles.md
@@ -8,4 +8,3 @@ Covers the evolution of basic computer security principles.
 > - Earl Boebert
 ## Commentary
 - *Defence in depth* seems often overlooked (having multiple layers of defences in a system), having *Compromise recording* seems to be in this vein also.
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diff --git a/70004 - Advanced Computer Security/Accountability.md b/70004 - Advanced Computer Security/Accountability.md
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+## Definition
+Being able to determine the attacker or [[Principle]].
+- Audit trails and logs, even in security failure there is a need to detect in order to react, and investigate after is system is re-secured.
+- Secure timestamping (e.g. using OS, or network, attacker may attempt to damage integrity of logs)
diff --git a/70004 - Advanced Computer Security/Availability.md b/70004 - Advanced Computer Security/Availability.md
@@ -0,0 +1,5 @@
+## Definition
+The uptime of a system.
+- Maximum traffic, measured historically and guaranteed by SLAs with providers.
+- Using redundancy to reduce possible single points of failure (e.g. replicating databases, auto-scaling for load)
+Many attacks are [[Denial of Service]].
diff --git a/70004 - Advanced Computer Security/Defence in Depth.md b/70004 - Advanced Computer Security/Defence in Depth.md
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+## Definition
+Using multiple layers of security, and monitoring to remove single points of failure for security.
+## Example
+### Account monitoring
+- Using password authentication for accounts.
+- Monitor number of denied logins, conservatively blocking clients that fail to log in repeatedly.
+- Monitor logins for suspicious activity, and block judiciously.
+- Monitor suspected compromised accounts.
diff --git a/70004 - Advanced Computer Security/Denial of Service.md b/70004 - Advanced Computer Security/Denial of Service.md
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+## Definition
+Overwhelming public services with large volumes of illegitimate traffic to prevent them servicing legitimate traffic.
diff --git a/70004 - Advanced Computer Security/Non-Reputation.md b/70004 - Advanced Computer Security/Non-Reputation.md
@@ -0,0 +1,6 @@
+## Definition
+> *Alice wants to prove to Trent she did communicate with Bob*
+
+Collecting undeniable evidence of some transaction.
+- receipts, digitally signed logs
+- helps with [[Accountability]], and for investigations (e.g. determining if a transaction was fraudulent, or valid based on an untrusted customer's testimony).
diff --git a/...igital Systems Design/1T_Dynamic_Cell.png → ...igital Systems Design/1T_Dynamic_Cell.png b/...igital Systems Design/1T_Dynamic_Cell.png → ...igital Systems Design/1T_Dynamic_Cell.png
diff --git a/...vanced Digital Systems Design/6T_SRAM.svg → ...vanced Digital Systems Design/6T_SRAM.svg b/...vanced Digital Systems Design/6T_SRAM.svg → ...vanced Digital Systems Design/6T_SRAM.svg
diff --git a/...Digital Systems Design/6T_Static_Cell.png → ...Digital Systems Design/6T_Static_Cell.png b/...Digital Systems Design/6T_Static_Cell.png → ...Digital Systems Design/6T_Static_Cell.png
diff --git a/...ital Systems Design/Abstraction Layers.md → ...ital Systems Design/Abstraction Layers.md b/...ital Systems Design/Abstraction Layers.md → ...ital Systems Design/Abstraction Layers.md
diff --git a/...Advanced Digital Systems Design/Adders.md → ...Advanced Digital Systems Design/Adders.md b/...Advanced Digital Systems Design/Adders.md → ...Advanced Digital Systems Design/Adders.md
diff --git a/...ced Digital Systems Design/Capacitance.md → ...ced Digital Systems Design/Capacitance.md b/...ced Digital Systems Design/Capacitance.md → ...ced Digital Systems Design/Capacitance.md
diff --git a/...tems Design/Content Addressable Memory.md → ...tems Design/Content Addressable Memory.md b/...tems Design/Content Addressable Memory.md → ...tems Design/Content Addressable Memory.md
diff --git a/...anced Digital Systems Design/DDR SDRAM.md → ...anced Digital Systems Design/DDR SDRAM.md b/...anced Digital Systems Design/DDR SDRAM.md → ...anced Digital Systems Design/DDR SDRAM.md
diff --git a/70046 - Advanced Digital Systems Design/DMA.md b/70046 - Advanced Digital Systems Design/DMA.md
@@ -0,0 +1,10 @@
+## Definition
+Rather than using the CPU to transfer data from main memory to a peripheral (wastes cycles), a separate DMA module does this (needs to update cache also).
+
+*Note: Here we reference main memory but this could apply to any bus connected perhipheral or cache.*
+## Modes
+| Mode | Description | Speed |
+| ---- | ---- | ---- |
+| Burst | DMA gains access to system bus and releases it on task completion | Fastest |
+| Cycle Stealing | DMA forces CPU to release bus, makes small transfer. Repeats until task is complete. | Slow |
+| Transparent/Interleaving | DMA only takes control of the bus when the CPU does not need it. | Slowest |
diff --git a/... Digital Systems Design/Dynamic Memory.md → ... Digital Systems Design/Dynamic Memory.md b/... Digital Systems Design/Dynamic Memory.md → ... Digital Systems Design/Dynamic Memory.md
diff --git a/...ced Digital Systems Design/FIFO Memory.md → ...ced Digital Systems Design/FIFO Memory.md b/...ced Digital Systems Design/FIFO Memory.md → ...ced Digital Systems Design/FIFO Memory.md
diff --git a/...anced Digital Systems Design/Flip Flop.md → ...anced Digital Systems Design/Flip Flop.md b/...anced Digital Systems Design/Flip Flop.md → ...anced Digital Systems Design/Flip Flop.md
diff --git a/... Design/Hardware Description Languages.md → ... Design/Hardware Description Languages.md b/... Design/Hardware Description Languages.md → ... Design/Hardware Description Languages.md
diff --git a/...dvanced Digital Systems Design/NIOS II.md → ...dvanced Digital Systems Design/NIOS II.md b/...dvanced Digital Systems Design/NIOS II.md → ...dvanced Digital Systems Design/NIOS II.md
diff --git a/...dvanced Digital Systems Design/Netlist.md → ...dvanced Digital Systems Design/Netlist.md b/...dvanced Digital Systems Design/Netlist.md → ...dvanced Digital Systems Design/Netlist.md
diff --git a/...l Systems Design/Parasitic Capacitance.md → ...l Systems Design/Parasitic Capacitance.md b/...l Systems Design/Parasitic Capacitance.md → ...l Systems Design/Parasitic Capacitance.md
diff --git a/...igital Systems Design/RAM Organisation.md → ...igital Systems Design/RAM Organisation.md b/...igital Systems Design/RAM Organisation.md → ...igital Systems Design/RAM Organisation.md
diff --git a/...d Digital Systems Design/Register File.md → ...d Digital Systems Design/Register File.md b/...d Digital Systems Design/Register File.md → ...d Digital Systems Design/Register File.md
diff --git a/...tems Design/Register Transfer Language.md → ...tems Design/Register Transfer Language.md b/...tems Design/Register Transfer Language.md → ...tems Design/Register Transfer Language.md
diff --git a/...Systems Design/Register Transfer Level.md → ...Systems Design/Register Transfer Level.md b/...Systems Design/Register Transfer Level.md → ...Systems Design/Register Transfer Level.md
diff --git a/...tal Systems Design/Register_File_Cell.png → ...tal Systems Design/Register_File_Cell.png b/...tal Systems Design/Register_File_Cell.png → ...tal Systems Design/Register_File_Cell.png
diff --git a/...esign/Register_file_read_write_timing.png → ...esign/Register_file_read_write_timing.png b/...esign/Register_file_read_write_timing.png → ...esign/Register_file_read_write_timing.png
diff --git a/70046 - Advanced Digital Systems Design/Roofline Model.md b/70046 - Advanced Digital Systems Design/Roofline Model.md
@@ -0,0 +1,9 @@
+## Definition
+*From the paper: [Roofline: an insightful visual performance model for multicore architectures: Communications of the ACM: Vol 52, No 4](https://dl.acm.org/doi/10.1145/1498765.1498785)*
+
+![[roofile_model.drawio.svg]]
+
+For example the original paper compare floating point arithmetic performance, and memory bandwidth.
+- We graph the attainable performance (i.e. $flops/s$ ) against the operational intensity (i.e. $flops/byte$). 
+- The gradient is $bytes/s$ (the memory bandwidth)
+- We get an increase up to a point (where $flops/s$ remains constant and it is compute bound)
diff --git a/...ed Digital Systems Design/SRAM_Access.png → ...ed Digital Systems Design/SRAM_Access.png b/...ed Digital Systems Design/SRAM_Access.png → ...ed Digital Systems Design/SRAM_Access.png
diff --git a/... Digital Systems Design/Soft Processor.md → ... Digital Systems Design/Soft Processor.md b/... Digital Systems Design/Soft Processor.md → ... Digital Systems Design/Soft Processor.md
diff --git a/...d Digital Systems Design/Static Memory.md → ...d Digital Systems Design/Static Memory.md b/...d Digital Systems Design/Static Memory.md → ...d Digital Systems Design/Static Memory.md
diff --git a/...ystems Design/Static vs Dynamic Memory.md → ...ystems Design/Static vs Dynamic Memory.md b/...ystems Design/Static vs Dynamic Memory.md → ...ystems Design/Static vs Dynamic Memory.md
diff --git a/...Systems Design/Synchronous Dynamic RAM.md → ...Systems Design/Synchronous Dynamic RAM.md b/...Systems Design/Synchronous Dynamic RAM.md → ...Systems Design/Synchronous Dynamic RAM.md
diff --git a/...al Systems Design/Taxonomy of Memories.md → ...al Systems Design/Taxonomy of Memories.md b/...al Systems Design/Taxonomy of Memories.md → ...al Systems Design/Taxonomy of Memories.md
diff --git a/...tal Systems Design/abstraction_layers.png → ...tal Systems Design/abstraction_layers.png b/...tal Systems Design/abstraction_layers.png → ...tal Systems Design/abstraction_layers.png
diff --git a/...tems Design/basic_memory_array.drawio.svg → ...tems Design/basic_memory_array.drawio.svg b/...tems Design/basic_memory_array.drawio.svg → ...tems Design/basic_memory_array.drawio.svg
diff --git a/70046 - Advanced Digital Systems Design/roofile_model.drawio.svg b/70046 - Advanced Digital Systems Design/roofile_model.drawio.svg
diff --git a/README.md b/README.md
@@ -24,5 +24,6 @@ A collection of textbook-like revision books, and obsidian notes for a selection
 - [70023 - Scalable Software Verification](70023%20-%20Scalable%20Software%20Verification)
 - [70024 - Software Reliability](70024%20-%20Software%20Reliability)
 - [70025 - Software Engineering for Industry](70025%20-%20Software%20Engineering%20for%20Industry)
+- [70046 - Advanced Digital Systems Design](70046%20-%20Advanced%20Digital%20Systems%20Design)
 
 ### [I want to contribute!](./.github/CONTRIBUTING.md)
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		## Definition
		Overwhelming public services with large volumes of illegitimate traffic to prevent them servicing legitimate traffic.