external: Add the memboot utility

The memboot tool is a small utility designed to be run on the ASPEED
BMC used in some OpenPower systems. It allows you to boot the P8 host
from the main system memory of the BMC rather than from the flash
memory.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 171 insertions, 0 deletions

diff --git a/external/memboot/Makefile b/external/memboot/Makefile
new file mode 100644
index 0000000..9b526a3
--- /dev/null
+++ b/external/memboot/Makefile
@@ -0,0 +1,14 @@
+all: memboot
+
+CFLAGS=-O2 -Wall
+
+memboot: memboot.c
+	$(CC) $(CFLAGS) -o $@ $^
+
+.PHONY: clean
+clean:
+	rm -rf memboot
+
+.PHONY: distclean
+distclean: clean
+	rm -rf *.c~ *.h~ *.i *.s Makefile~
diff --git a/external/memboot/README b/external/memboot/README
new file mode 100644
index 0000000..20158ed
--- /dev/null
+++ b/external/memboot/README
@@ -0,0 +1,24 @@
+memboot
+=======
+
+This is a small utility designed to be run on the ASPEED BMC used in
+some OpenPower systems. It allows you to boot the P8 host from the
+main system memory of the BMC rather than from the flash memory.
+
+This is mainly useful for firmware development as it makes it possible
+to try new firmware images without first having to write the new image
+to flash memory which can be a lengthy process.
+
+Building:
+---------
+
+CC=<arm toolchain> make
+
+Usage:
+-----
+
+./memboot <flash image> - Will cause the P8 host to boot from BMC
+	  	 	  system memory at next power on.
+
+./memboot 		- Will boot the system from flash memory at next
+			  power on.
diff --git a/external/memboot/memboot.c b/external/memboot/memboot.c
new file mode 100644
index 0000000..fa42ea9
--- /dev/null
+++ b/external/memboot/memboot.c
@@ -0,0 +1,133 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+/* Where to put the firmware image if booting from memory */
+#define MEM_IMG_BASE (0x5c000000)
+
+/* Start of flash memory if booting from flash */
+#define FLASH_IMG_BASE (0x30000000)
+
+/* LPC registers */
+#define LPC_BASE		0x1e789000
+#define LPC_HICR6		0x80
+#define LPC_HICR7		0x88
+#define LPC_HICR8		0x8c
+
+uint32_t readl(void *addr)
+{
+	asm volatile("" : : : "memory");
+	return *(volatile uint32_t *)addr;
+}
+
+void writel(uint32_t val, void *addr)
+{
+	asm volatile("" : : : "memory");
+	*(volatile uint32_t *)addr = val;
+}
+
+void copy_flash_img(int mem_fd, int flash_fd, unsigned int size)
+{
+	static void *memimg, *fwimg;
+	size_t pagesize = getpagesize();
+
+	memimg = mmap(NULL, ((size/pagesize)+1)*pagesize,
+		      PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, MEM_IMG_BASE);
+	if (memimg == MAP_FAILED) {
+		perror("Unable to map image destination memory");
+		exit(1);
+	}
+
+	fwimg = mmap(NULL,size, PROT_READ, MAP_SHARED, flash_fd, 0);
+	if (fwimg == MAP_FAILED) {
+		perror("Unable to open image source memory");
+		exit(1);
+	}
+
+	/* Copy boot image */
+	memcpy(memimg, fwimg, size);
+}
+
+void boot_firmware_image(int mem_fd, char *filename)
+{
+	int fw_fd;
+	struct stat st;
+
+	fw_fd = open(filename, O_RDONLY);
+	if (fw_fd < 0) {
+		perror("Unable to open flash image\n");
+		exit(1);
+	}
+
+	if (stat(filename, &st)) {
+		perror("Unable to determine size of firmware image");
+		exit(1);
+	}
+
+	if (st.st_size > 32*1024*1024) {
+		fprintf(stderr, "Flash too large (> 32MB)");
+		exit(1);
+	}
+
+	copy_flash_img(mem_fd, fw_fd, st.st_size);
+	close(fw_fd);
+}
+
+int main(int argc, char *argv[])
+{
+	int mem_fd;
+	void *lpcreg;
+	uint32_t lpc_hicr7_val = (FLASH_IMG_BASE | 0xe00);
+
+	if (argc > 2) {
+		printf("Usage: %s <flash image>\n", argv[0]);
+		exit(1);
+	}
+
+	mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+	if (mem_fd < 0) {
+		perror("Unable to open /dev/mem");
+		exit(1);
+	}
+
+	lpcreg = mmap(NULL, getpagesize(),
+		      PROT_READ | PROT_WRITE, MAP_SHARED, mem_fd, LPC_BASE);
+	if (lpcreg == MAP_FAILED) {
+		perror("Unable to map LPC register memory");
+		exit(1);
+	}
+
+	if (argc == 2) {
+		boot_firmware_image(mem_fd, argv[1]);
+		lpc_hicr7_val = (MEM_IMG_BASE | 0xe00);
+		printf("Booting from memory after power cycle\n");
+	}
+
+	if (readl(lpcreg + LPC_HICR7) != lpc_hicr7_val) {
+		printf("Resetting LPC_HICR7 to 0x%x\n", lpc_hicr7_val);
+		writel(lpc_hicr7_val, lpcreg+LPC_HICR7);
+	}
+
+	printf("LPC_HICR7 = 0x%x\n", lpc_hicr7_val);
+	return 0;
+}