xv6-65oo2/kernel/entry.S
2019-07-23 14:31:12 -04:00

27 lines
694 B
ArmAsm

# 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