1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/entry.S b/kernel/entry.S
new file mode 100644
index 0000000..ef5a56a
--- /dev/null
+++ b/kernel/entry.S
@@ -0,0 +1,26 @@
+	# qemu -kernel starts at 0x1000. the instructions
+        # there seem to be provided by qemu, as if it
+        # were a ROM. the code at 0x1000 jumps to
+        # 0x8000000, the _start function here,
+        # in machine mode. each CPU starts here.
+.section .data
+.globl stack0
+.section .text
+.globl start
+.section .text
+.globl _entry
+_entry:
+	# set up a stack for C.
+        # stack0 is declared in start.c,
+        # with a 4096-byte stack per CPU.
+        # sp = stack0 + (hartid * 4096)
+        la sp, stack0
+        li a0, 1024*4
+	csrr a1, mhartid
+        addi a1, a1, 1
+        mul a0, a0, a1
+        add sp, sp, a0
+	# jump to start() in start.c
+        call start
+junk:
+        j junk