func SetupLinuxBootParams(
model *machine.Model,
boot_params_data []byte,
orig_boot_params_data []byte,
cmdline_addr platform.Paddr,
initrd_addr platform.Paddr,
initrd_len uint64) error {
// Grab a reference to our boot params struct.
boot_params := (*C.struct_boot_params)(unsafe.Pointer(&boot_params_data[0]))
// The setup header.
// First step is to copy the existing setup_header
// out of the given kernel image. We copy only the
// header, and not the rest of the setup page.
setup_start := 0x01f1
setup_end := 0x0202 + int(orig_boot_params_data[0x0201])
if setup_end > platform.PageSize {
return InvalidSetupHeader
}
C.memcpy(
unsafe.Pointer(&boot_params_data[setup_start]),
unsafe.Pointer(&orig_boot_params_data[setup_start]),
C.size_t(setup_end-setup_start))
// Setup our BIOS memory map.
// NOTE: We have to do this via C bindings. This is really
// annoying, but basically because of the unaligned structures
// in the struct_boot_params, the Go code generated here is
// actually *incompatible* with the actual C layout.
// First, the count.
C.e820_set_count(boot_params, C.int(len(model.MemoryMap)))
// Then, fill out the region information.
for index, region := range model.MemoryMap {
var memtype C.int
switch region.MemoryType {
case machine.MemoryTypeUser:
memtype = C.E820Ram
case machine.MemoryTypeReserved:
memtype = C.E820Reserved
case machine.MemoryTypeSpecial:
memtype = C.E820Reserved
case machine.MemoryTypeAcpi:
memtype = C.E820Acpi
}
C.e820_set_region(
boot_params,
C.int(index),
C.__u64(region.Start),
C.__u64(region.Size),
C.__u8(memtype))
}
// Set necessary setup header bits.
C.set_header(
boot_params,
C.__u64(initrd_addr),
C.__u64(initrd_len),
C.__u64(cmdline_addr))
// All done!
return nil
}
func Set_header(s unsafe.Pointer, key string, value string) {
key_ptr := to_ptr(key)
value_ptr := to_ptr(value)
C.set_header((*C.servlet)(s), (*C.char)(key_ptr), (*C.char)(value_ptr))
}
