selfboot: Move x86 quirk under arch

Making exceptions for some payload to be loaded near
and under 1 MiB boundary sounds like a legacy 16-bit
x86 BIOS thing we generally do not want under lib/.

Change-Id: I8e8336a03d6f06d8f022c880a8334fe19a777f0a
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/26934
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/arch/x86/boot.c

@@ -11,6 +11,7 @@
  * GNU General Public License for more details.
  */
 
+#include <commonlib/helpers.h>
 #include <console/console.h>
 #include <arch/stages.h>
 #include <program_loading.h>
@@ -205,6 +206,17 @@ int arch_supports_bounce_buffer(void)
 	return 1;
 }
 
+int payload_arch_usable_ram_quirk(uint64_t start, uint64_t size)
+{
+	if (start < 1 * MiB && (start + size) <= 1 * MiB) {
+		printk(BIOS_DEBUG,
+			"Payload being loaded at below 1MiB without region being marked as RAM usable.\n");
+		return 1;
+	}
+
+	return 0;
+}
+
 static void try_payload(struct prog *prog)
 {
 	if (prog_type(prog) == PROG_PAYLOAD) {

src/include/program_loading.h

@@ -188,6 +188,8 @@ void backup_ramstage_section(uintptr_t base, size_t size);
  *   PAYLOAD LOADING   *
  ***********************/
 
+int payload_arch_usable_ram_quirk(uint64_t start, uint64_t size);
+
 /* Load payload into memory in preparation to run. */
 void payload_load(void);
 

src/lib/selfboot.c

@@ -333,9 +333,13 @@ static int build_self_segment_list(
 	return 1;
 }
 
+__weak int payload_arch_usable_ram_quirk(uint64_t start, uint64_t size)
+{
+	return 0;
+}
+
 static int payload_targets_usable_ram(struct segment *head)
 {
-	const unsigned long one_meg = (1UL << 20);
 	struct segment *ptr;
 
 	for (ptr = head->next; ptr != head; ptr = ptr->next) {
@@ -343,13 +347,8 @@ static int payload_targets_usable_ram(struct segment *head)
 						      ptr->s_memsz))
 			continue;
 
-		if (ptr->s_dstaddr < one_meg &&
+		if (payload_arch_usable_ram_quirk(ptr->s_dstaddr, ptr->s_memsz))
-		    (ptr->s_dstaddr + ptr->s_memsz) <= one_meg) {
-			printk(BIOS_DEBUG,
-				"Payload being loaded at below 1MiB "
-				"without region being marked as RAM usable.\n");
 			continue;
-		}
 
 		/* Payload segment not targeting RAM. */
 		printk(BIOS_ERR, "SELF Payload doesn't target RAM:\n");