arm: switch to EFI, drop FDT in loader

* This should 'fix' the arm build
* No longer parse FDT in bootloader, just pass ptr.
* The EFI loader doesn't load yet on arm
* It compiles though. Ship it!

Change-Id: I7c8ce588298dfaf4fba8054c6b6d9a92733b5943
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2903
Reviewed-by: Alex von Gluck IV <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

build/jam/ArchitectureRules

@@ -244,8 +244,8 @@ rule KernelArchitectureSetup architecture
 			HAIKU_BOOT_ARCHIVE_IMAGE_OFFSET = 384 ; # in kB
 
 		case arm :
-			HAIKU_KERNEL_PLATFORM ?= u-boot ;
-			HAIKU_BOOT_TARGETS += u-boot ;
+			HAIKU_KERNEL_PLATFORM ?= efi ;
+			HAIKU_BOOT_TARGETS += efi ;
 
 			HAIKU_BOOT_SDIMAGE_SIZE ?= 32 ;
 			# SOC's like allwinner need an offset to skip the hardcoded initial loader

src/system/kernel/arch/arm/arch_debug_console.cpp

@@ -95,7 +95,9 @@ status_t
 arch_debug_console_init(kernel_args *args)
 {
 	// first try with hints from the FDT
-	gArchDebugUART = debug_uart_from_fdt(args->platform_args.fdt);
+	// TODO: Use UEFI somehow
+
+	//gArchDebugUART = debug_uart_from_fdt(args->platform_args.fdt);
 
 	// Do we can some kind of direct fallback here
 	// (aka, guess arch_get_uart_pl011 or arch_get_uart_8250?)

src/system/kernel/arch/arm/arch_platform.cpp

@@ -10,18 +10,12 @@
 #include <arch/platform.h>
 #include <boot/kernel_args.h>
 
-#include <drivers/bus/FDT.h>
-
-char *gFDT;
 
 status_t
 arch_platform_init(struct kernel_args *kernelArgs)
 {
 	// NOTE: dprintf() is off-limits here, too early...
 
-	// If we have an FDT blob, point the gFDT to it now
-	gFDT = (char *)kernelArgs->platform_args.fdt;
-
 	return B_OK;
 }