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authorJonathan Neuschäfer <j.neuschaefer@gmx.net>2016-06-10 19:35:15 +0200
committerMartin Roth <martinroth@google.com>2016-06-12 12:42:32 +0200
commit1282b8d99692ddfff5b78b03938b9b3555b17c00 (patch)
treec8141a7cd0789c9b24c4da9a7065312fe13fefa1
parentf934efc9f8e2fe0791f47e7088301199629827b1 (diff)
downloadcoreboot-1282b8d99692ddfff5b78b03938b9b3555b17c00.tar.xz
arch/riscv: Compile with -mcmodel=medany
In the default (medlow) code model, pointers are loaded with a lui, addi instruction sequence: lui a0, 0xNNNNN addi a0, a0, 0xNNN Since lui sign-extends bits 32-63 from bit 31 on RV64, lui/addi can't load pointers just above 0x80000000, where RISC-V's RAM now lives. The medany code model gets around this restriction by loading pointers trough auipc and addi: auipc a0, 0xNNNNN addi a0, a0, 0xNNN This way, any pointer within the current pc ±2G can be loaded, which is by far sufficient for coreboot. Change-Id: I77350d9218a687284c1337d987765553cf915a22 Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-on: https://review.coreboot.org/15148 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
-rw-r--r--src/arch/riscv/Makefile.inc5
1 files changed, 4 insertions, 1 deletions
diff --git a/src/arch/riscv/Makefile.inc b/src/arch/riscv/Makefile.inc
index 4521dcbba6..243fa5364e 100644
--- a/src/arch/riscv/Makefile.inc
+++ b/src/arch/riscv/Makefile.inc
@@ -15,7 +15,7 @@
##
################################################################################
-riscv_flags = -I$(src)/arch/riscv/
+riscv_flags = -I$(src)/arch/riscv/ -mcmodel=medany
riscv_asm_flags =
@@ -48,6 +48,9 @@ $(objcbfs)/bootblock.debug: $$(bootblock-objs)
-T $(call src-to-obj,bootblock,src/mainboard/$(MAINBOARDDIR)/memlayout.ld) --whole-archive --start-group $(filter-out %.ld,$(bootblock-objs)) \
$(LIBGCC_FILE_NAME_bootblock) --end-group $(COMPILER_RT_bootblock)
+bootblock-c-ccopts += $(riscv_flags)
+bootblock-S-ccopts += $(riscv_asm_flags)
+
endif
################################################################################