From 700f4c412d42c9b9811269045c0e363a0331bba9 Mon Sep 17 00:00:00 2001 From: Wojtek Kosior Date: Sat, 28 Dec 2019 21:54:42 +0100 Subject: split kernel into 2 stages; second stage gets copied to 0x0 and runs from there --- kernel_stage1.ld | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 kernel_stage1.ld (limited to 'kernel_stage1.ld') diff --git a/kernel_stage1.ld b/kernel_stage1.ld new file mode 100644 index 0000000..3130634 --- /dev/null +++ b/kernel_stage1.ld @@ -0,0 +1,27 @@ +ENTRY(_boot) /* defined in boot.S; qemu needs it to run elf file */ + +/* Code starts at 0x8000 - that's where RPis in 32-bit mode load + * kernel at. My experiments do, however, show, that qemu emulating + * RPi2 loads the kernel at 0x10000! (took some pain to find out). + * rpi-open-firmware, on the other hand, loads kernel at 0x2000000! + * This is not really a problem, since: + * 1. We can use our bootloader to load the kernel at 0x8000 + * 2. We've rewritten stage 1 of both bootloader and kernel in + * careful assembly, so that they should work regardless of + * where they are loaded. + * 3. In qemu, we can load kernel.elf instead of raw binary + * (qemu will do the right thing then) + */ + +SECTIONS +{ + + . = 0x8000; + + __start = .; + .kernel_stage1 : + { + KEEP(kernel_stage1.o) + } + __end = .; +} -- cgit v1.2.3