lib: Rewrite qemu-armv7 ramdetect
* Move armv7 RAM dection to a common place
* Enable it for all emulated platforms
* Use 32bit probe values and restore memory even on failure
* Use the new logic on the following boards:
** qemu-armv7
** qemu-riscv
Tested on qemu-system-riscv:
Fixes kernel panic due to wrong memory limits reported.
Change-Id: I37386c6a95bfc3b7b25aeae32c6e14cff9913513
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33934
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/include/ramdetect.h b/src/include/ramdetect.h
new file mode 100644
index 0000000..b63cdf1
--- /dev/null
+++ b/src/include/ramdetect.h
@@ -0,0 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Probe an area if it's read/writable.
+ * Primary use case is the detection of DRAM amount on emulators.
+ *
+ * @param dram_start Physical address of DRAM start
+ * @param probe_size Maximum size in MiB to probe for
+ * @return The detected DRAM size in MiB
+ */
+size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size);
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 7492b16..9deb5bf 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -65,6 +65,7 @@
verstage-$(CONFIG_GENERIC_UDELAY) += timer.c
verstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c
+romstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
romstage-y += prog_loaders.c
romstage-y += prog_ops.c
romstage-y += memchr.c
@@ -105,6 +106,7 @@
romstage-$(CONFIG_GENERIC_UDELAY) += timer.c
+ramstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
ramstage-y += prog_loaders.c
ramstage-y += prog_ops.c
ramstage-y += hardwaremain.c
@@ -155,6 +157,7 @@
ramstage-y += imd_cbmem.c
ramstage-y += imd.c
+postcar-$(CONFIG_VENDOR_EMULATION) += ramdetect.c
postcar-y += cbmem_common.c
postcar-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c
postcar-y += imd_cbmem.c
diff --git a/src/lib/ramdetect.c b/src/lib/ramdetect.c
new file mode 100644
index 0000000..5416a58
--- /dev/null
+++ b/src/lib/ramdetect.c
@@ -0,0 +1,78 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <types.h>
+#include <symbols.h>
+#include <device/mmio.h>
+#include <ramdetect.h>
+#include <console/console.h>
+
+#define OVERLAP(a, b, s, e) ((b) > (s) && (a) < (e))
+
+static int probe_mb(const uintptr_t dram_start, const uintptr_t size)
+{
+ uintptr_t addr = dram_start + (size * MiB) - sizeof(uint32_t);
+ static const uint32_t patterns[] = {
+ 0x55aa55aa,
+ 0x12345678
+ };
+ void *ptr = (void *) addr;
+ size_t i;
+
+ /* Don't accidentally clober oneself. */
+ if (OVERLAP(addr, addr + sizeof(uint32_t), (uintptr_t)_program, (uintptr_t) _eprogram))
+ return 1;
+
+ uint32_t old = read32(ptr);
+ for (i = 0; i < ARRAY_SIZE(patterns); i++) {
+ write32(ptr, patterns[i]);
+ if (read32(ptr) != patterns[i])
+ break;
+ }
+
+ write32(ptr, old);
+ return i == ARRAY_SIZE(patterns);
+}
+
+/* - 20 as probe_size is in MiB, - 1 as i is signed */
+#define MAX_ADDRESSABLE_SPACE (sizeof(size_t) * 8 - 20 - 1)
+
+/* Probe an area if it's read/writable. */
+size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size)
+{
+ ssize_t i;
+ size_t msb = 0;
+ size_t discovered = 0;
+
+ static size_t saved_result;
+ if (saved_result)
+ return saved_result;
+
+ /* Find the MSB + 1. */
+ size_t tmp = probe_size;
+ do {
+ msb++;
+ } while (tmp >>= 1);
+
+ /* Limit search to accessible address space */
+ msb = MIN(msb, MAX_ADDRESSABLE_SPACE);
+
+ /* Compact binary search. */
+ for (i = msb; i >= 0; i--)
+ if (probe_mb(dram_start, (discovered | (1ULL << i))))
+ discovered |= (1ULL << i);
+
+ saved_result = discovered;
+ printk(BIOS_DEBUG, "RAMDETECT: Found %zu MiB RAM\n", discovered);
+ return discovered;
+}
diff --git a/src/mainboard/emulation/qemu-armv7/Kconfig b/src/mainboard/emulation/qemu-armv7/Kconfig
index fc770cf..73b2d5d 100644
--- a/src/mainboard/emulation/qemu-armv7/Kconfig
+++ b/src/mainboard/emulation/qemu-armv7/Kconfig
@@ -53,4 +53,8 @@
string
default "ARM Ltd."
+config DRAM_SIZE_MB
+ int
+ default 1024
+
endif # BOARD_EMULATION_QEMU_ARMV7
diff --git a/src/mainboard/emulation/qemu-armv7/cbmem.c b/src/mainboard/emulation/qemu-armv7/cbmem.c
index 927bd42..542e08d 100644
--- a/src/mainboard/emulation/qemu-armv7/cbmem.c
+++ b/src/mainboard/emulation/qemu-armv7/cbmem.c
@@ -11,55 +11,11 @@
* GNU General Public License for more details.
*/
-#include <stddef.h>
#include <cbmem.h>
#include <symbols.h>
-#include <device/mmio.h>
-#include "mainboard.h"
-
-#define PATTERN1 0x55
-#define PATTERN2 0xaa
-
-/* Returns 1 if mebibyte mb is present and 0 otherwise. */
-static int probe_mb(int mb)
-{
- char *ptr = (char *) 0x60000000 + (mb << 20) + 0xfffff;
- char old;
- if (ptr < (char *) &_eprogram) {
- /* Don't probe below _end to avoid accidentally clobering
- oneself. */
- return 1;
- }
-
- old = read8(ptr);
- write8(ptr, PATTERN1);
- if (read8(ptr) != PATTERN1)
- return 0;
- write8(ptr, PATTERN2);
- if (read8(ptr) != PATTERN2)
- return 0;
- write8(ptr, old);
- return 1;
-}
-
-int probe_ramsize(void)
-{
- int i;
- int discovered = 0;
- static int saved_result;
- if (saved_result)
- return saved_result;
- /* Compact binary search. */
- /* 1 GiB is the largest supported RAM by this machine. */
- for (i = 9; i >= 0; i--)
- if (probe_mb(discovered | (1 << i)))
- discovered |= (1 << i);
- discovered++;
- saved_result = discovered;
- return discovered;
-}
+#include <ramdetect.h>
void *cbmem_top(void)
{
- return _dram + (probe_ramsize() << 20);
+ return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) * MiB);
}
diff --git a/src/mainboard/emulation/qemu-armv7/mainboard.c b/src/mainboard/emulation/qemu-armv7/mainboard.c
index cc14dd8..338cff9 100644
--- a/src/mainboard/emulation/qemu-armv7/mainboard.c
+++ b/src/mainboard/emulation/qemu-armv7/mainboard.c
@@ -18,9 +18,10 @@
#include <device/device.h>
#include <cbmem.h>
#include <halt.h>
-#include "mainboard.h"
#include <edid.h>
#include <device/mmio.h>
+#include <ramdetect.h>
+#include <symbols.h>
static void init_gfx(void)
{
@@ -57,7 +58,7 @@
halt();
}
- discovered = probe_ramsize();
+ discovered = probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB);
printk(BIOS_DEBUG, "%d MiB of RAM discovered\n", discovered);
ram_resource(dev, 0, 0x60000000 >> 10, discovered << 10);
cbmem_recovery(0);
diff --git a/src/mainboard/emulation/qemu-armv7/mainboard.h b/src/mainboard/emulation/qemu-armv7/mainboard.h
deleted file mode 100644
index 87fa3be..0000000
--- a/src/mainboard/emulation/qemu-armv7/mainboard.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2016 Vladimir Serbinenko <phcoder@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 or, at your option, any later
- * version of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#ifndef QEMU_ARMV7_MAINBOARD_H
-#define QEMU_ARMV7_MAINBOARD_H
-
-/* Returns RAM size in mebibytes. */
-int probe_ramsize(void);
-
-#endif
diff --git a/src/mainboard/emulation/qemu-riscv/mainboard.c b/src/mainboard/emulation/qemu-riscv/mainboard.c
index 4b428aa..02356aa 100644
--- a/src/mainboard/emulation/qemu-riscv/mainboard.c
+++ b/src/mainboard/emulation/qemu-riscv/mainboard.c
@@ -17,15 +17,19 @@
#include <device/device.h>
#include <cbmem.h>
#include <symbols.h>
+#include <ramdetect.h>
static void mainboard_enable(struct device *dev)
{
+ size_t dram_mb_detected;
if (!dev) {
die("No dev0; die\n");
}
- ram_resource(dev, 0, (uintptr_t)_dram / KiB, CONFIG_DRAM_SIZE_MB * KiB);
+ dram_mb_detected = probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB);
+ ram_resource(dev, 0, (uintptr_t)_dram / KiB, dram_mb_detected / KiB);
+
cbmem_recovery(0);
}
diff --git a/src/soc/ucb/riscv/cbmem.c b/src/soc/ucb/riscv/cbmem.c
index 2ee400a..542e08d 100644
--- a/src/soc/ucb/riscv/cbmem.c
+++ b/src/soc/ucb/riscv/cbmem.c
@@ -12,16 +12,10 @@
*/
#include <cbmem.h>
+#include <symbols.h>
+#include <ramdetect.h>
void *cbmem_top(void)
{
- uintptr_t base;
- size_t size;
-
- /* Use dummy values until we can query the memory size again */
- //query_mem(configstring(), &base, &size);
- base = 0x80000000;
- size = 128 * MiB;
-
- return (void *)(base + size);
+ return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) * MiB);
}