From: Hau Hsu <hau.hsu@sifive.com>
To: hau.hsu@sifive.com, newlib@sourceware.org, kito.cheng@gmail.com
Subject: [PATCH] RISC-V: Initialize the jvt CSR
Date: Mon, 25 Sep 2023 13:36:57 +0800 [thread overview]
Message-ID: <20230925053657.24959-1-hau.hsu@sifive.com> (raw)
We set symbol '__jvt_base$' as weak. So if the symbol is not set in the
linker script, the address would be 0. We initialize jvt CSR only if
the address is not 0.
psabi reference:
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/2d770815dc9a8b11e61ea1abd487cb25ee56ad5e/riscv-elf.adoc#table-jump-relaxation
---
libgloss/riscv/crt0.S | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/libgloss/riscv/crt0.S b/libgloss/riscv/crt0.S
index 7a4e4e32c..4744ba039 100644
--- a/libgloss/riscv/crt0.S
+++ b/libgloss/riscv/crt0.S
@@ -26,6 +26,16 @@ _start:
addi gp, gp, %pcrel_lo(1b)
.option pop
+ /* Initialize jvt CSR */
+ .weak __jvt_base$
+.option push
+.option arch, +zcmt, +zicsr
+ lla a0, __jvt_base$
+ beqz a0, .Ljvt_init_end
+ csrw jvt, a0
+.Ljvt_init_end:
+.option pop
+
# Clear the bss segment
la a0, __bss_start
la a2, _end
--
2.42.0
next reply other threads:[~2023-09-25 5:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-25 5:36 Hau Hsu [this message]
2023-09-25 6:17 ` Kito Cheng
2023-09-27 1:17 ` Hau Hsu
2023-09-29 2:26 ` Kito Cheng
2024-01-05 3:07 Hau Hsu
2024-01-05 6:49 ` Kito Cheng
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