Initial commit

Mainly with the code I took from @popovicu's blog.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

5 files changed, 57 insertions, 0 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
new file mode 100644
index 0000000..e943353
--- /dev/null
+++ b/kernel/Makefile
@@ -0,0 +1,20 @@
+CROSS_AS 	?= riscv64-suse-linux-as
+CROSS_LD 	?= riscv64-suse-linux-ld
+ASFLAGS  	 = -march=rv64g -mabi=lp64
+
+##
+# Targets
+
+.PHONY: infinite
+infinite: clean
+	$(CROSS_AS) $(ASFLAGS) -o infinite.o -c infinite.s
+	$(CROSS_LD) -T infinite.ld infinite.o -o infinite
+
+.PHONY: hello
+hello: clean
+	$(CROSS_AS) $(ASFLAGS) -o hello.o -c hello.s
+	$(CROSS_LD) -T hello.ld hello.o -o hello
+
+.PHONY: clean
+clean:
+	@rm -f *.o infinite hello
diff --git a/kernel/hello.ld b/kernel/hello.ld
new file mode 100644
index 0000000..e4af459
--- /dev/null
+++ b/kernel/hello.ld
@@ -0,0 +1,9 @@
+MEMORY {
+  kernel_space (rwx) : ORIGIN = 0x80200000, LENGTH = 128
+}
+
+SECTIONS {
+  .text : {
+    hello.o(.text.kernel)
+  } > kernel_space
+}
diff --git a/kernel/hello.s b/kernel/hello.s
new file mode 100644
index 0000000..eacd797
--- /dev/null
+++ b/kernel/hello.s
@@ -0,0 +1,15 @@
+.global _start
+.section .text.kernel
+
+_start: li a7, 0x4442434E
+        li a6, 0x00
+        li a0, 12
+        lla a1, debug_string
+        li a2, 0
+        ecall
+
+loop:   j loop
+
+        .section .rodata
+debug_string:
+        .string "Hello world\n"
diff --git a/kernel/infinite.ld b/kernel/infinite.ld
new file mode 100644
index 0000000..2eee384
--- /dev/null
+++ b/kernel/infinite.ld
@@ -0,0 +1,9 @@
+MEMORY {
+  kernel_space (rwx) : ORIGIN = 0x80200000, LENGTH = 128
+}
+
+SECTIONS {
+  .text : {
+    infinite.o(.text.kernel)
+  } > kernel_space
+}
diff --git a/kernel/infinite.s b/kernel/infinite.s
new file mode 100644
index 0000000..855f58e
--- /dev/null
+++ b/kernel/infinite.s
@@ -0,0 +1,4 @@
+	.global _start
+	.section .text.kernel
+
+_start:	j _start