readme: add captions to all tables and images

Author: cirosantilli

README.adoc

@@ -4513,8 +4513,10 @@ xcalc
 xeyes
 ....
 
-Outcome:
+Outcome: <<image-x11>>
 
+[[image-x11]]
+.X11 Buildroot graphical user interface screenshot
 image:x11.png[image]
 
 We don't build X11 by default because it takes a considerable amount of time (about 20%), and is not expected to be used by most users: you need to pass the `-x` flag to enable it.
@@ -7725,8 +7727,10 @@ TODO: didn't port during refactor after 3b0a343647bed577586989fb702b760bd280844a
 * `qemu/docs/tracing.txt` and `qemu/docs/replay.txt`
 * https://stackoverflow.com/questions/39149446/how-to-use-qemus-simple-trace-backend/46497873#46497873
 
-Results (boot not excluded):
+Results (boot not excluded): <<table-boot-instruction-counts>>
 
+[[table-boot-instruction-counts]]
+.Boot instruction counts for various setups
 [options="header"]
 |===
 |Commit |Arch |Simulator |Instruction count
@@ -10026,8 +10030,10 @@ A quick `+./run --emulator gem5 -- -h+` leads us to the options:
 --l3_size=1024
 ....
 
-But keep in mind that it only affects benchmark performance of the most detailed CPU types:
+But keep in mind that it only affects benchmark performance of the most detailed CPU types: <<table-gem5-cache-cpu-type>>
 
+[[table-gem5-cache-cpu-type]]
+.gem5 cache support in function of CPU type
 [options="header"]
 |===
 |arch |CPU type |caches used
@@ -12139,8 +12145,10 @@ Questions about the C inline assembly examples:
 
 === Linux calling conventions
 
-Summary:
+Summary: <<table-linux-calling-conventions>>
 
+[[table-linux-calling-conventions]]
+.Summary of Linux calling conventions for several architectures
 [options="header"]
 |===
 |arch |arguments |return value |callee saved registers
@@ -12240,8 +12248,10 @@ Let's see how many bytes go into each data type:
 * link:userland/arch/arm/gas_data_sizes.S[]
 * link:userland/arch/aarch64/gas_data_sizes.S[]
 
-Conclusion:
+Conclusion: <<table-gas-data-sizes>>
 
+[[table-gas-data-sizes]]
+.Summary of GNU GAS assembler data sizes
 [options="header"]
 |===
 |.byte |.word |.long |.quad |.octa
@@ -12388,9 +12398,11 @@ Has some Intel vs AT&T name overload hell:
 * https://stackoverflow.com/questions/17170388/trying-to-understand-the-assembly-instruction-cltd-on-x86/50315201#50315201
 * https://sourceware.org/binutils/docs/as/i386_002dMnemonics.html
 
-GNU GAS accepts both syntaxes:
+GNU GAS accepts both syntaxes: <<table-cqto-cltq>>
 
-[options="header"]
+[[table-cqto-cltq]]
+.CQTO and CLTQ family Intel vs AT&T
+[options="header", cols="3*<"]
 |===
 |Intel |AT&T |From |To
 
@@ -14271,8 +14283,10 @@ The vector table format is described on <<armarm8>> Table D1-7 "Vector offsets f
 
 A good representation of the format of the vector table can also be found at <<armv8-programmers-guide>> Table 10-2 "Vector table offsets from vector table base address".
 
-The first part of the table contains:
+The first part of the table contains: <<table-armv8-vector-handlers>>
 
+[[table-armv8-vector-handlers]]
+.Summary of ARMv8 vector handlers
 [options="header"]
 |===
 |Address |Exception type |Description
@@ -16480,8 +16494,10 @@ In order to learn how to measure some of those aspects, see: <<benchmark-this-re
 
 ==== Linux distro choice
 
-We haven't found the ultimate distro yet, here is a summary table of trade-offs that we care about:
+We haven't found the ultimate distro yet, here is a summary table of trade-offs that we care about: <<table-lkmc-linux-distro-comparison>>
 
+[[table-lkmc-linux-distro-comparison]]
+.Comparison of Linux distros for usage in this repository
 [options="header"]
 |===
 |Distro |Packages in single Git tree |Git tracked docs |Cross build without QEMU |Prebuilt downloads |Number of packages