QEMU breakpoint at start_kernel

gdbinit

# For RISC-V Linux v5.18

# Add Linux symbol (before MMU setup)
add-symbol-file vmlinux -o -0xfffffffeffe00000

# OpenSBI symbol
add-symbol-file fw_jump.elf

# Linux kernel 1st line
br *0x80200000
c

# Tricky routine to set breakpoint just after MMU setup ($pc at 0xffffffff80001160)
# refer to: https://elixir.bootlin.com/linux/v5.18/source/arch/riscv/kernel/head.S#L73
# 1) goto relocate_enable_mmu()
br relocate_enable_mmu
c
# 2) si to instr 'csrw    satp,a0'
si 22
# 3) goto return address of relocate_enable_mmu()
#    (remove breakpoint / symbol file before MMU setup)
br *$ra
del 1
remove-symbol-file -a 0x0000000080200000
c
# 4) Add Linux symbol (after MMU setup)
add-symbol-file vmlinux

# Normal use: (e.g. start_kernel)
br start_kernel