diff options
author | Dylan McKay <me@dylanmckay.io> | 2017-09-11 10:32:51 +0000 |
---|---|---|
committer | Dylan McKay <me@dylanmckay.io> | 2017-09-11 10:32:51 +0000 |
commit | fe79297f6f6a700979f6f70c39d93f6a430b2a15 (patch) | |
tree | bd7fe1403ae43d9abc99b8ce40a0bb24e0d9d0bb /lib/Target/AVR | |
parent | 5b272fa4557722c8ee9623b473ef3ae17cf2a7cf (diff) |
[AVR] Enable the '__do_copy_data' function
Also enables '__do_clear_bss'.
These functions are automaticalled called by the CRT if they are
declared.
We need these to be called otherwise RAM will start completely
uninitialised, even though we need to copy RAM variables from progmem to
RAM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312905 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/AVR')
-rw-r--r-- | lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.cpp | 20 | ||||
-rw-r--r-- | lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h | 2 |
2 files changed, 22 insertions, 0 deletions
diff --git a/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.cpp b/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.cpp index a2d8c16eeb8..2b45d9adc7e 100644 --- a/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.cpp +++ b/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.cpp @@ -13,6 +13,8 @@ #include "AVRTargetStreamer.h" +#include "llvm/MC/MCContext.h" + namespace llvm { AVRTargetStreamer::AVRTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {} @@ -20,5 +22,23 @@ AVRTargetStreamer::AVRTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {} AVRTargetAsmStreamer::AVRTargetAsmStreamer(MCStreamer &S) : AVRTargetStreamer(S) {} +void AVRTargetStreamer::finish() { + MCStreamer &OS = getStreamer(); + MCContext &Context = OS.getContext(); + + MCSymbol *DoCopyData = Context.getOrCreateSymbol("__do_copy_data"); + MCSymbol *DoClearBss = Context.getOrCreateSymbol("__do_clear_bss"); + + // FIXME: We can disable __do_copy_data if there are no static RAM variables. + + OS.emitRawComment(" Declaring this symbol tells the CRT that it should"); + OS.emitRawComment("copy all variables from program memory to RAM on startup"); + OS.EmitSymbolAttribute(DoCopyData, MCSA_Global); + + OS.emitRawComment(" Declaring this symbol tells the CRT that it should"); + OS.emitRawComment("clear the zeroed data section on startup"); + OS.EmitSymbolAttribute(DoClearBss, MCSA_Global); +} + } // end namespace llvm diff --git a/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h b/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h index 99a536699ae..815088b0a5d 100644 --- a/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h +++ b/lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h @@ -19,6 +19,8 @@ class MCStreamer; class AVRTargetStreamer : public MCTargetStreamer { public: explicit AVRTargetStreamer(MCStreamer &S); + + void finish() override; }; /// A target streamer for textual AVR assembly code. |