KASLR address is needed to boot fully functional Android. KASLR is set by primary bootloader, and since u-boot is used as a secondary bootloader(replacing kernel) on sdm845 platform, KASLR may be found by comparing memory chunks at relocaddr over supposed KASLR range.
Signed-off-by: Dzmitry Sankouski dsankouski@gmail.com --- arch/arm/mach-snapdragon/init_sdm845.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/arm/mach-snapdragon/init_sdm845.c b/arch/arm/mach-snapdragon/init_sdm845.c index 5f53c21947..1f88502394 100644 --- a/arch/arm/mach-snapdragon/init_sdm845.c +++ b/arch/arm/mach-snapdragon/init_sdm845.c @@ -78,5 +78,23 @@ __weak int misc_init_r(void) env_set("key_power", "0"); }
+ /* + * search for kaslr address, set by primary bootloader by searching first + * 0x100 relocated bytes at u-boot's initial load address range + */ + uintptr_t start = gd->ram_base; + uintptr_t end = start + 0x800000; + u8 *addr = (u8 *)start; + phys_addr_t *relocaddr = (phys_addr_t *)gd->relocaddr; + u32 block_size = 0x1000; + + while (memcmp(addr, relocaddr, 0x100) && (uintptr_t)addr < end) + addr += block_size; + + if ((uintptr_t)addr >= end) + printf("KASLR not found in range 0x%lx - 0x%lx", start, end); + else + env_set_addr("KASLR", addr); + return 0; }