fix image location.

chapter2.adoc

@@ -84,7 +84,7 @@ Finally, if no such above entry exists, the transaction is illegal with error ty
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title="an example block diagram of an IOPMP. It illustrates the checking flow of an IOPMP. This IOPMP takes three inputs: RRID, the transaction type (read/write), and the request range (address/len). It first looks up the SRCMD table according to the RRID carried by the incoming transaction to retrieve associated MD indexes and the corresponding permissions related to these MDs. By the MD indexes, the IOPMP looks up the MDCFG table to get the belonging entry indexes. The final step checks the access right according to the above entry indexes and corresponding permissions. An interrupt, an error response, and/or a record is generated once the transaction fails the permission check in the step.", id=iopmp-block-diagram]
-image::iopmp_unit_block_diagram.png[]
+image::images/iopmp_unit_block_diagram.png[]
 
 [#SECTION_2_7]
 === Error Reactions

chapter3.adoc

@@ -61,15 +61,15 @@ For the sake of convenience of discussion, some highly used combinations of *HWC
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title="an example block diagram of the rapid-4 model. The flow is the same as in <<iopmp-block-diagram>>, except the MDCFG table is simplified to a constant mapping illustrated in the dashed box. In this example, every MD has exactly four entries."]
-image::iopmp_unit_block_diagram_rapid_4.png[]
+image::images/iopmp_unit_block_diagram_rapid_4.png[]
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title="an example block diagram of the compact-4 model."]
-image::iopmp_unit_block_diagram_compact_4.png[]
+image::images/iopmp_unit_block_diagram_compact_4.png[]
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title="an example block diagram of the model implements SRCMD table format 2 and MDCFG table format 1 with HWCFG0.md_entry_num is 0. In this example, every MD has exactly single entry, i.e., the entry index is equal to the MD index."]
-image::iopmp_unit_block_diagram_srcmd_fmt2.png[]
+image::images/iopmp_unit_block_diagram_srcmd_fmt2.png[]
 
 [#SECTION_3_5]
 === Configuration Protection

intro.adoc

@@ -8,7 +8,7 @@ IOPMP is considered a hardware component in a bus fabric. But why is a pure-soft
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title="Figure 1: Example integrations of IOPMP(s) in a system. Figure (a) shows a system deploying two IOPMPs (destination-enforcement). The IOPMPs take three inputs: RRID, the transaction type (read/write), and the request range (address/len). Figure (b) shows a system deploying two IOPMPs (source-enforcement). In this deployment, the RRID can be ignored."]
-image::iopmp_system_position.png[]
+image::images/iopmp_system_position.png[]
 
 Another hardware component in a bus matrix, the Input-Output Memory Management Unit (IOMMU), is used to translate a virtual address in a device to a physical address in the bus matrix by one or more stages of page tables. It could be operated in a trusted or untrusted environment and typically is a tool of a hypervisor or an OS. It provides excellent flexibility and reduces external memory fragmentation. However, it may not be an ideal tool for security software running in M-mode because it needs relatively large memory and relatively complicated software compared to a typical security monitor. Besides, the tables are usually stored in the DRAM, which is outside the chip and needs extra protection. For simple systems, this burden may not be affordable. IOPMP, however, consumes much less memory and stores rules inside the chip. Both of them have their own useful areas of application, so IOMMU and IOPMP could coexist and collaborate. IOPMP can be used as a tool for the secure monitor by checking access from devices controlled by other software, while IOMMU can be used by software with richer resources.
 

iopmp.adoc

@@ -9,8 +9,8 @@
 :preface-title: Preamble
 :colophon:
 :appendix-caption: Appendix
-:imagesdir: images
-:title-logo-image: image:risc-v_logo.svg[pdfwidth=3.25in,align=center]
+:imagesdir: .
+:title-logo-image: image:./docs-resources/images/risc-v_logo.svg[pdfwidth=3.25in,align=center]
 // Settings:
 :experimental:
 :reproducible: