rk3288: Add CBMEM console support and fix RETURN_FROM_VERSTAGE

Since we can now reduce our vboot2 work buffer by 4K, we can use all
that hard-earned space for the CBMEM console instead (and 4K are
unfortunately barely enough for all the stuff we dump with vboot2).

Also add console_init() and exception_init() to the verstage for
CONFIG_RETURN_FROM_VERSTAGE, which was overlooked before (our model
requires those functions to be called again at the beginning of every
stage... even though some consoles like UARTs might not need it, others
like the CBMEM console do). In the !RETURN_FROM_VERSTAGE case, this is
expected to be done by the platform-specific verstage entry wrapper, and
already in place for the only implementation we have for now (tegra124).

(Technically, there is still a bug in the case where EARLY_CONSOLE is
set but BOOTBLOCK_CONSOLE isn't, since both verstage and romstage would
run init_console_ptr() as if they were there first, so the romstage
overwrites the verstage's output. I don't think it's worth fixing that
now, since EARLY_CONSOLE && !BOOTBLOCK_CONSOLE is a pretty pointless
use-case and I think we should probably just get rid of the
CONFIG_BOOTBLOCK_CONSOLE option eventually.)

BRANCH=None
BUG=None
TEST=Booted Pinky.

Change-Id: I87914df3c72f0262eb89f337454009377a985497
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 85486928abf364c5d5d1cf69f7668005ddac023c
Original-Change-Id: Id666cb7a194d32cfe688861ab17c5e908bc7760d
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/232614
Reviewed-on: http://review.coreboot.org/9607
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/arch/arm/include/armv4/arch/exception.h

@@ -30,6 +30,6 @@
 #ifndef _ARCH_EXCEPTION_H
 #define _ARCH_EXCEPTION_H
 
-static void exception_init(void) { /* not implemented */ }
+static inline void exception_init(void) { /* not implemented */ }
 
 #endif

src/arch/x86/include/arch/exception.h

@@ -30,6 +30,6 @@
 #ifndef _ARCH_EXCEPTION_H
 #define _ARCH_EXCEPTION_H
 
-static void exception_init(void) { /* not implemented */ }
+static inline void exception_init(void) { /* not implemented */ }
 
 #endif

src/soc/rockchip/rk3288/include/soc/memlayout.ld

@@ -35,15 +35,16 @@ SECTIONS
 	SRAM_START(0xFF700000)
 	TTB(0xFF700000, 16K)
 	BOOTBLOCK(0xFF704004, 15K - 4)
-	TTB_SUBTABLES(0xFF707c00, 1K)
-	VBOOT2_WORK(0xFF708000, 16K)
+	TTB_SUBTABLES(0xFF707C00, 1K)
+	PRERAM_CBMEM_CONSOLE(0xFF708000, 4K)
+	VBOOT2_WORK(0xFF709000, 12K)
 	OVERLAP_VERSTAGE_ROMSTAGE(0xFF70C000, 40K)
 	PRERAM_CBFS_CACHE(0xFF716000, 4K)
 	STACK(0xFF717000, 4K)
 	SRAM_END(0xFF718000)
 
-	/* 4K of special SRAM in PMU power domain. Careful: only supports 32-bit
-	 * wide write accesses! Only use with MMU and writeback mapping. */
+	/* 4K of special SRAM in PMU power domain.
+	 * Careful: only supports 32-bit wide write accesses! */
 	SYMBOL(pmu_sram, 0xFF720000)
 	SYMBOL(epmu_sram, 0xFF721000)
 }

src/vendorcode/google/chromeos/vboot2/verstage.c

@@ -18,6 +18,7 @@
  */
 
 #include <antirollback.h>
+#include <arch/exception.h>
 #include <console/console.h>
 #include <console/vtxprintf.h>
 #include <string.h>
@@ -166,11 +167,7 @@ static void save_if_needed(struct vb2_context *ctx)
  * TODO: Avoid loading a stage twice (once in hash_body & again in load_stage).
  * when per-stage verification is ready.
  */
-#if CONFIG_RETURN_FROM_VERSTAGE
-void main(void)
-#else
 void verstage_main(void)
-#endif /* CONFIG_RETURN_FROM_VERSTAGE */
 {
 	struct vb2_context ctx;
 	struct vboot_region fw_main;
@@ -249,3 +246,12 @@ void verstage_main(void)
 	printk(BIOS_INFO, "Slot %c is selected\n", is_slot_a(&ctx) ? 'A' : 'B');
 	vb2_set_selected_region(wd, &fw_main);
 }
+
+#if IS_ENABLED(CONFIG_RETURN_FROM_VERSTAGE)
+void main(void)
+{
+	console_init();
+	exception_init();
+	verstage_main();
+}
+#endif