diff --git a/gcc/config/avr/avr-devices.cc b/gcc/config/avr/avr-devices.cc
index 627a7db54dc..90846f3da21 100644
--- a/gcc/config/avr/avr-devices.cc
+++ b/gcc/config/avr/avr-devices.cc
@@ -93,8 +93,8 @@ avr_texinfo[] =
     "``Enhanced'' devices with 3-byte PC, i.e.@: with more than 128@tie{}KiB "
     "of program memory." },
   { ARCH_AVRTINY,
-    "``TINY'' Tiny core devices with 512@tie{}B up to 4@tie{}KiB of "
-    "program memory." },
+    "``Reduced Tiny'' Tiny core devices with only 16 general purpose "
+    "registers and 512@tie{}B up to 4@tie{}KiB of program memory." },
   { ARCH_AVRXMEGA2,
     "``XMEGA'' devices with more than 8@tie{}KiB and up to 64@tie{}KiB "
     "of program memory." },
diff --git a/gcc/config/avr/gen-avr-mmcu-texi.cc b/gcc/config/avr/gen-avr-mmcu-texi.cc
index c756d69e89c..d928236e172 100644
--- a/gcc/config/avr/gen-avr-mmcu-texi.cc
+++ b/gcc/config/avr/gen-avr-mmcu-texi.cc
@@ -189,7 +189,8 @@ int main (void)
 
 	  for (i = 0; i < ARRAY_SIZE (avr_texinfo); i++)
 	    if (arch_id == avr_texinfo[i].arch_id)
-	      printf ("@item %s\n%s\n", mcu->name, avr_texinfo[i].texinfo);
+	      printf ("@item @anchor{%s}%s\n%s\n", mcu->name, mcu->name,
+		      avr_texinfo[i].texinfo);
 	}
       else if (arch_id == (enum avr_arch_id) mcu->arch_id)
 	{
diff --git a/gcc/doc/avr-mmcu.texi b/gcc/doc/avr-mmcu.texi
index ddd429e082c..c73ea53e6ce 100644
--- a/gcc/doc/avr-mmcu.texi
+++ b/gcc/doc/avr-mmcu.texi
@@ -12,71 +12,71 @@
 
 @table @code
 
-@item avr2
+@item @anchor{avr2}avr2
 ``Classic'' devices with up to 8@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{attiny22}, @code{attiny26}, @code{at90s2313}, @code{at90s2323}, @code{at90s2333}, @code{at90s2343}, @code{at90s4414}, @code{at90s4433}, @code{at90s4434}, @code{at90c8534}, @code{at90s8515}, @code{at90s8535}.
 
-@item avr25
+@item @anchor{avr25}avr25
 ``Classic'' devices with up to 8@tie{}KiB of program memory and with the @code{MOVW} instruction.
 @*@var{mcu}@tie{}= @code{attiny13}, @code{attiny13a}, @code{attiny24}, @code{attiny24a}, @code{attiny25}, @code{attiny261}, @code{attiny261a}, @code{attiny2313}, @code{attiny2313a}, @code{attiny43u}, @code{attiny44}, @code{attiny44a}, @code{attiny45}, @code{attiny48}, @code{attiny441}, @code{attiny461}, @code{attiny461a}, @code{attiny4313}, @code{attiny84}, @code{attiny84a}, @code{attiny85}, @code{attiny87}, @code{attiny88}, @code{attiny828}, @code{attiny841}, @code{attiny861}, @code{attiny861a}, @code{ata5272}, @code{ata6616c}, @code{at86rf401}.
 
-@item avr3
+@item @anchor{avr3}avr3
 ``Classic'' devices with 16@tie{}KiB up to 64@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{at76c711}, @code{at43usb355}.
 
-@item avr31
+@item @anchor{avr31}avr31
 ``Classic'' devices with 128@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atmega103}, @code{at43usb320}.
 
-@item avr35
+@item @anchor{avr35}avr35
 ``Classic'' devices with 16@tie{}KiB up to 64@tie{}KiB of program memory and with the @code{MOVW} instruction.
 @*@var{mcu}@tie{}= @code{attiny167}, @code{attiny1634}, @code{atmega8u2}, @code{atmega16u2}, @code{atmega32u2}, @code{ata5505}, @code{ata6617c}, @code{ata664251}, @code{at90usb82}, @code{at90usb162}.
 
-@item avr4
+@item @anchor{avr4}avr4
 ``Enhanced'' devices with up to 8@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atmega48}, @code{atmega48a}, @code{atmega48p}, @code{atmega48pa}, @code{atmega48pb}, @code{atmega8}, @code{atmega8a}, @code{atmega8hva}, @code{atmega88}, @code{atmega88a}, @code{atmega88p}, @code{atmega88pa}, @code{atmega88pb}, @code{atmega8515}, @code{atmega8535}, @code{ata6285}, @code{ata6286}, @code{ata6289}, @code{ata6612c}, @code{at90pwm1}, @code{at90pwm2}, @code{at90pwm2b}, @code{at90pwm3}, @code{at90pwm3b}, @code{at90pwm81}.
 
-@item avr5
+@item @anchor{avr5}avr5
 ``Enhanced'' devices with 16@tie{}KiB up to 64@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atmega16}, @code{atmega16a}, @code{atmega16hva}, @code{atmega16hva2}, @code{atmega16hvb}, @code{atmega16hvbrevb}, @code{atmega16m1}, @code{atmega16u4}, @code{atmega161}, @code{atmega162}, @code{atmega163}, @code{atmega164a}, @code{atmega164p}, @code{atmega164pa}, @code{atmega165}, @code{atmega165a}, @code{atmega165p}, @code{atmega165pa}, @code{atmega168}, @code{atmega168a}, @code{atmega168p}, @code{atmega168pa}, @code{atmega168pb}, @code{atmega169}, @code{atmega169a}, @code{atmega169p}, @code{atmega169pa}, @code{atmega32}, @code{atmega32a}, @code{atmega32c1}, @code{atmega32hvb}, @code{atmega32hvbrevb}, @code{atmega32m1}, @code{atmega32u4}, @code{atmega32u6}, @code{atmega323}, @code{atmega324a}, @code{atmega324p}, @code{atmega324pa}, @code{atmega324pb}, @code{atmega325}, @code{atmega325a}, @code{atmega325p}, @code{atmega325pa}, @code{atmega328}, @code{atmega328p}, @code{atmega328pb}, @code{atmega329}, @code{atmega329a}, @code{atmega329p}, @code{atmega329pa}, @code{atmega3250}, @code{atmega3250a}, @code{atmega3250p}, @code{atmega3250pa}, @code{atmega3290}, @code{atmega3290a}, @code{atmega3290p}, @code{atmega3290pa}, @code{atmega406}, @code{atmega64}, @code{atmega64a}, @code{atmega64c1}, @code{atmega64hve}, @code{atmega64hve2}, @code{atmega64m1}, @code{atmega64rfr2}, @code{atmega640}, @code{atmega644}, @code{atmega644a}, @code{atmega644p}, @code{atmega644pa}, @code{atmega644rfr2}, @code{atmega645}, @code{atmega645a}, @code{atmega645p}, @code{atmega649}, @code{atmega649a}, @code{atmega649p}, @code{atmega6450}, @code{atmega6450a}, @code{atmega6450p}, @code{atmega6490}, @code{atmega6490a}, @code{atmega6490p}, @code{ata5795}, @code{ata5790}, @code{ata5790n}, @code{ata5791}, @code{ata6613c}, @code{ata6614q}, @code{ata5782}, @code{ata5831}, @code{ata8210}, @code{ata8510}, @code{ata5702m322}, @code{at90pwm161}, @code{at90pwm216}, @code{at90pwm316}, @code{at90can32}, @code{at90can64}, @code{at90scr100}, @code{at90usb646}, @code{at90usb647}, @code{at94k}, @code{m3000}.
 
-@item avr51
+@item @anchor{avr51}avr51
 ``Enhanced'' devices with 128@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atmega128}, @code{atmega128a}, @code{atmega128rfa1}, @code{atmega128rfr2}, @code{atmega1280}, @code{atmega1281}, @code{atmega1284}, @code{atmega1284p}, @code{atmega1284rfr2}, @code{at90can128}, @code{at90usb1286}, @code{at90usb1287}.
 
-@item avr6
+@item @anchor{avr6}avr6
 ``Enhanced'' devices with 3-byte PC, i.e.@: with more than 128@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atmega256rfr2}, @code{atmega2560}, @code{atmega2561}, @code{atmega2564rfr2}.
 
-@item avrxmega2
+@item @anchor{avrxmega2}avrxmega2
 ``XMEGA'' devices with more than 8@tie{}KiB and up to 64@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atxmega8e5}, @code{atxmega16a4}, @code{atxmega16a4u}, @code{atxmega16c4}, @code{atxmega16d4}, @code{atxmega16e5}, @code{atxmega32a4}, @code{atxmega32a4u}, @code{atxmega32c3}, @code{atxmega32c4}, @code{atxmega32d3}, @code{atxmega32d4}, @code{atxmega32e5}, @code{avr64da28}, @code{avr64da32}, @code{avr64da48}, @code{avr64da64}, @code{avr64db28}, @code{avr64db32}, @code{avr64db48}, @code{avr64db64}, @code{avr64dd14}, @code{avr64dd20}, @code{avr64dd28}, @code{avr64dd32}, @code{avr64ea28}, @code{avr64ea32}, @code{avr64ea48}.
 
-@item avrxmega3
+@item @anchor{avrxmega3}avrxmega3
 ``XMEGA'' devices with up to 64@tie{}KiB of combined program memory and RAM, and with program memory visible in the RAM address space.
 @*@var{mcu}@tie{}= @code{attiny202}, @code{attiny204}, @code{attiny212}, @code{attiny214}, @code{attiny402}, @code{attiny404}, @code{attiny406}, @code{attiny412}, @code{attiny414}, @code{attiny416}, @code{attiny417}, @code{attiny424}, @code{attiny426}, @code{attiny427}, @code{attiny804}, @code{attiny806}, @code{attiny807}, @code{attiny814}, @code{attiny816}, @code{attiny817}, @code{attiny824}, @code{attiny826}, @code{attiny827}, @code{attiny1604}, @code{attiny1606}, @code{attiny1607}, @code{attiny1614}, @code{attiny1616}, @code{attiny1617}, @code{attiny1624}, @code{attiny1626}, @code{attiny1627}, @code{attiny3214}, @code{attiny3216}, @code{attiny3217}, @code{attiny3224}, @code{attiny3226}, @code{attiny3227}, @code{atmega808}, @code{atmega809}, @code{atmega1608}, @code{atmega1609}, @code{atmega3208}, @code{atmega3209}, @code{atmega4808}, @code{atmega4809}, @code{avr16dd14}, @code{avr16dd20}, @code{avr16dd28}, @code{avr16dd32}, @code{avr32da28}, @code{avr32da32}, @code{avr32da48}, @code{avr32db28}, @code{avr32db32}, @code{avr32db48}, @code{avr32dd14}, @code{avr32dd20}, @code{avr32dd28}, @code{avr32dd32}.
 
-@item avrxmega4
+@item @anchor{avrxmega4}avrxmega4
 ``XMEGA'' devices with more than 64@tie{}KiB and up to 128@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atxmega64a3}, @code{atxmega64a3u}, @code{atxmega64a4u}, @code{atxmega64b1}, @code{atxmega64b3}, @code{atxmega64c3}, @code{atxmega64d3}, @code{atxmega64d4}, @code{avr128da28}, @code{avr128da32}, @code{avr128da48}, @code{avr128da64}, @code{avr128db28}, @code{avr128db32}, @code{avr128db48}, @code{avr128db64}.
 
-@item avrxmega5
+@item @anchor{avrxmega5}avrxmega5
 ``XMEGA'' devices with more than 64@tie{}KiB and up to 128@tie{}KiB of program memory and more than 64@tie{}KiB of RAM.
 @*@var{mcu}@tie{}= @code{atxmega64a1}, @code{atxmega64a1u}.
 
-@item avrxmega6
+@item @anchor{avrxmega6}avrxmega6
 ``XMEGA'' devices with more than 128@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{atxmega128a3}, @code{atxmega128a3u}, @code{atxmega128b1}, @code{atxmega128b3}, @code{atxmega128c3}, @code{atxmega128d3}, @code{atxmega128d4}, @code{atxmega192a3}, @code{atxmega192a3u}, @code{atxmega192c3}, @code{atxmega192d3}, @code{atxmega256a3}, @code{atxmega256a3b}, @code{atxmega256a3bu}, @code{atxmega256a3u}, @code{atxmega256c3}, @code{atxmega256d3}, @code{atxmega384c3}, @code{atxmega384d3}.
 
-@item avrxmega7
+@item @anchor{avrxmega7}avrxmega7
 ``XMEGA'' devices with more than 128@tie{}KiB of program memory and more than 64@tie{}KiB of RAM.
 @*@var{mcu}@tie{}= @code{atxmega128a1}, @code{atxmega128a1u}, @code{atxmega128a4u}.
 
-@item avrtiny
-``TINY'' Tiny core devices with 512@tie{}B up to 4@tie{}KiB of program memory.
+@item @anchor{avrtiny}avrtiny
+``Reduced Tiny'' Tiny core devices with only 16 general purpose registers and 512@tie{}B up to 4@tie{}KiB of program memory.
 @*@var{mcu}@tie{}= @code{attiny4}, @code{attiny5}, @code{attiny9}, @code{attiny10}, @code{attiny102}, @code{attiny104}, @code{attiny20}, @code{attiny40}.
 
-@item avr1
+@item @anchor{avr1}avr1
 This ISA is implemented by the minimal AVR core and supported for assembler only.
 @*@var{mcu}@tie{}= @code{attiny11}, @code{attiny12}, @code{attiny15}, @code{attiny28}, @code{at90s1200}.
 
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 84eef411e2d..eebff4071e8 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -8288,21 +8288,20 @@ at all.
 @item io
 @itemx io (@var{addr})
 Variables with the @code{io} attribute are used to address
-memory-mapped peripherals in the io address range.
+memory-mapped peripherals in the I/O address range.
+No memory is allocated.
 If an address is specified, the variable
 is assigned that address, and the value is interpreted as an
 address in the data address space.
 Example:
 
 @smallexample
-volatile int porta __attribute__((io (0x22)));
+volatile int porta __attribute__((io (__AVR_SFR_OFFSET__ + 0x2)));
 @end smallexample
 
-The address specified in the address in the data address range.
-
-Otherwise, the variable it is not assigned an address, but the
-compiler will still use in/out instructions where applicable,
-assuming some other module assigns an address in the io address range.
+Otherwise, the variable is not assigned an address, but the
+compiler will still use @code{in} and @code{out} instructions where applicable,
+assuming some other module assigns an address in the I/O address range.
 Example:
 
 @smallexample
@@ -8320,13 +8319,28 @@ instructions.
 @cindex @code{address} variable attribute, AVR
 @item address
 @itemx address (@var{addr})
-Variables with the @code{address} attribute are used to address
-memory-mapped peripherals that may lie outside the io address range.
+Variables with the @code{address} attribute can be used to address
+memory-mapped peripherals that may lie outside the I/O address range.
+Just like with the @code{io} and @code{io_low} attributes, no memory is
+allocated.
 
 @smallexample
 volatile int porta __attribute__((address (0x600)));
 @end smallexample
 
+This attribute can also be used to define symbols in C/C++
+code which otherwise would require assembly, a linker description file
+or command line options like @code{-Wl,--defsym,a_symbol=@var{value}}.
+For example,
+@smallexample
+int a_symbol __attribute__((weak, address (1234)));
+@end smallexample
+will be compiled to
+@smallexample
+.weak a_symbol
+a_symbol = 1234
+@end smallexample
+
 @cindex @code{absdata} variable attribute, AVR
 @item absdata
 Variables in static storage and with the @code{absdata} attribute can
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 68d1f364ac0..585ce1a15e9 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -23808,6 +23808,7 @@ Warn if the ISR is misspelled, i.e.@: without __vector prefix.
 Enabled by default.
 @end table
 
+@anchor{eind}
 @subsubsection @code{EIND} and Devices with More Than 128 Ki Bytes of Flash
 @cindex @code{EIND}
 Pointers in the implementation are 16@tie{}bits wide.
@@ -23944,6 +23945,7 @@ and the application be linked with @option{-Wl,--defsym,func_4=0x4}.
 Alternatively, @code{func_4} can be defined in the linker script.
 @end itemize
 
+@anchor{ramp}
 @subsubsection Handling of the @code{RAMPD}, @code{RAMPX}, @code{RAMPY} and @code{RAMPZ} Special Function Registers
 @cindex @code{RAMPD}
 @cindex @code{RAMPX}
@@ -23986,6 +23988,7 @@ you must reset it to zero after the access.
 
 @end itemize
 
+@anchor{avr-macros}
 @subsubsection AVR Built-in Macros
 
 GCC defines several built-in macros so that the user code can test
