New mechanism to define SRAM/memory map with automatic bounds checking

This patch creates a new mechanism to define the static memory layout
(primarily in SRAM) for a given board, superseding the brittle mass of
Kconfigs that we were using before. The core part is a memlayout.ld file
in the mainboard directory (although boards are expected to just include
the SoC default in most cases), which is the primary linker script for
all stages (though not rmodules for now). It uses preprocessor macros
from <memlayout.h> to form a different valid linker script for all
stages while looking like a declarative, boilerplate-free map of memory
addresses to the programmer. Linker asserts will automatically guarantee
that the defined regions cannot overlap. Stages are defined with a
maximum size that will be enforced by the linker. The file serves to
both define and document the memory layout, so that the documentation
cannot go missing or out of date.

The mechanism is implemented for all boards in the ARM, ARM64 and MIPS
architectures, and should be extended onto all systems using SRAM in the
future. The CAR/XIP environment on x86 has very different requirements
and the layout is generally not as static, so it will stay like it is
and be unaffected by this patch (save for aligning some symbol names for
consistency and sharing the new common ramstage linker script include).

BUG=None
TEST=Booted normally and in recovery mode, checked suspend/resume and
the CBMEM console on Falco, Blaze (both normal and vboot2), Pinky and
Pit. Compiled Ryu, Storm and Urara, manually compared the disassemblies
with ToT and looked for red flags.

Change-Id: Ifd2276417f2036cbe9c056f17e42f051bcd20e81
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: f1e2028e7ebceeb2d71ff366150a37564595e614
Original-Change-Id: I005506add4e8fcdb74db6d5e6cb2d4cb1bd3cda5
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/213370
Reviewed-on: http://review.coreboot.org/9283
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Tauner <stefan.tauner@gmx.at>
Reviewed-by: Aaron Durbin <adurbin@google.com>

5 files changed, 21 insertions, 21 deletions

diff --git a/src/mainboard/google/nyan/Kconfig b/src/mainboard/google/nyan/Kconfig
index 864e577c3d..082985d211 100644
--- a/src/mainboard/google/nyan/Kconfig
+++ b/src/mainboard/google/nyan/Kconfig
@@ -42,14 +42,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "Nyan"
 
-config DRAM_DMA_START
-	hex
-	default 0x90000000
-
-config DRAM_DMA_SIZE
-	hex
-	default 0x00200000
-
 choice
 	prompt "BCT boot media"
 	default NYAN_BCT_CFG_SPI
diff --git a/src/mainboard/google/nyan/Makefile.inc b/src/mainboard/google/nyan/Makefile.inc
index 7ac11e8a33..6506abaf6e 100644
--- a/src/mainboard/google/nyan/Makefile.inc
+++ b/src/mainboard/google/nyan/Makefile.inc
@@ -42,3 +42,7 @@ ramstage-y += reset.c
 ramstage-y += boardid.c
 ramstage-y += mainboard.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
+
+bootblock-y += memlayout.ld
+romstage-y += memlayout.ld
+ramstage-y += memlayout.ld
diff --git a/src/mainboard/google/nyan/mainboard.c b/src/mainboard/google/nyan/mainboard.c
index b534ea908d..e52db83d18 100644
--- a/src/mainboard/google/nyan/mainboard.c
+++ b/src/mainboard/google/nyan/mainboard.c
@@ -30,6 +30,7 @@
 #include <soc/nvidia/tegra124/pmc.h>
 #include <soc/nvidia/tegra124/spi.h>
 #include <soc/nvidia/tegra/usb.h>
+#include <symbols.h>
 #include <vendorcode/google/chromeos/chromeos.h>
 
 static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
@@ -268,6 +269,6 @@ void lb_board(struct lb_header *header)
 	dma = (struct lb_range *)lb_new_record(header);
 	dma->tag = LB_TAB_DMA;
 	dma->size = sizeof(*dma);
-	dma->range_start = CONFIG_DRAM_DMA_START;
-	dma->range_size = CONFIG_DRAM_DMA_SIZE;
+	dma->range_start = (uintptr_t)_dma_coherent;
+	dma->range_size = _dma_coherent_size;
 }
diff --git a/src/mainboard/google/nyan/memlayout.ld b/src/mainboard/google/nyan/memlayout.ld
new file mode 100644
index 0000000000..33ce6446ad
--- /dev/null
+++ b/src/mainboard/google/nyan/memlayout.ld
@@ -0,0 +1 @@
+#include <soc/nvidia/tegra124/memlayout.ld>
diff --git a/src/mainboard/google/nyan/romstage.c b/src/mainboard/google/nyan/romstage.c
index 1ff500b5d3..f2077bbb27 100644
--- a/src/mainboard/google/nyan/romstage.c
+++ b/src/mainboard/google/nyan/romstage.c
@@ -39,6 +39,7 @@
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/display.h>
+#include <symbols.h>
 #include <timestamp.h>
 
 static void __attribute__((noinline)) romstage(void)
@@ -52,24 +53,25 @@ static void __attribute__((noinline)) romstage(void)
 	sdram_init(get_sdram_config());
 
 	/* used for MMU and CBMEM setup, in MB */
-	u32 dram_start = (CONFIG_SYS_SDRAM_BASE >> 20);
-	u32 dram_end = sdram_max_addressable_mb();	/* plus one... */
-	u32 dram_size = dram_end - dram_start;
+	u32 dram_start_mb = (uintptr_t)_dram/MiB;
+	u32 dram_end_mb = sdram_max_addressable_mb();
+	u32 dram_size_mb = dram_end_mb - dram_start_mb;
 
 	configure_l2_cache();
 	mmu_init();
 	/* Device memory below DRAM is uncached. */
-	mmu_config_range(0, dram_start, DCACHE_OFF);
-	/* SRAM is cached. Round the size up to 2MB, the LPAE page size. */
-	mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK);
+	mmu_config_range(0, dram_start_mb, DCACHE_OFF);
+	/* SRAM is cached. MMU code will round size up to page size. */
+	mmu_config_range((uintptr_t)_sram/MiB, div_round_up(_sram_size, MiB),
+			 DCACHE_WRITEBACK);
 	/* DRAM is cached. */
-	mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK);
+	mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK);
 	/* A window for DMA is uncached. */
-	mmu_config_range(CONFIG_DRAM_DMA_START >> 20,
-			 CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF);
+	mmu_config_range((uintptr_t)_dma_coherent/MiB,
+			 _dma_coherent_size/MiB, DCACHE_OFF);
 	/* The space above DRAM is uncached. */
-	if (dram_end < 4096)
-		mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF);
+	if (dram_end_mb < 4096)
+		mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF);
 	mmu_disable_range(0, 1);
 	dcache_mmu_enable();