remoteproc: add elf file load support

The current implementation supports only binary file load.
Add helpers to support ELF32 format (sanity check, and load).
Note that since an ELF32 image is built for the remote processor, the
load function uses the device_to_virt ops to translate the addresses.
Implement a basic translation for sandbox_testproc.

Add related tests. Test result:
=> ut dm remoteproc_elf
Test: dm_test_remoteproc_elf: remoteproc.c
Test: dm_test_remoteproc_elf: remoteproc.c (flat tree)
Failures: 0

Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

3 files changed, 126 insertions, 1 deletions

diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 77eb708523..7517947b6d 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -4,7 +4,7 @@
 # Texas Instruments Incorporated - http://www.ti.com/
 #
 
-obj-$(CONFIG_$(SPL_)REMOTEPROC) += rproc-uclass.o
+obj-$(CONFIG_$(SPL_)REMOTEPROC) += rproc-uclass.o rproc-elf-loader.o
 
 # Remote proc drivers - Please keep this list alphabetically sorted.
 obj-$(CONFIG_K3_SYSTEM_CONTROLLER) += k3_system_controller.o
diff --git a/drivers/remoteproc/rproc-elf-loader.c b/drivers/remoteproc/rproc-elf-loader.c
new file mode 100644
index 0000000000..67937a7595
--- /dev/null
+++ b/drivers/remoteproc/rproc-elf-loader.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ */
+#include <common.h>
+#include <dm.h>
+#include <elf.h>
+#include <remoteproc.h>
+
+/* Basic function to verify ELF32 image format */
+int rproc_elf32_sanity_check(ulong addr, ulong size)
+{
+	Elf32_Ehdr *ehdr;
+	char class;
+
+	if (!addr) {
+		pr_debug("Invalid fw address?\n");
+		return -EFAULT;
+	}
+
+	if (size < sizeof(Elf32_Ehdr)) {
+		pr_debug("Image is too small\n");
+		return -ENOSPC;
+	}
+
+	ehdr = (Elf32_Ehdr *)addr;
+	class = ehdr->e_ident[EI_CLASS];
+
+	if (!IS_ELF(*ehdr) || ehdr->e_type != ET_EXEC || class != ELFCLASS32) {
+		pr_debug("Not an executable ELF32 image\n");
+		return -EPROTONOSUPPORT;
+	}
+
+	/* We assume the firmware has the same endianness as the host */
+# ifdef __LITTLE_ENDIAN
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
+# else /* BIG ENDIAN */
+	if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
+# endif
+		pr_debug("Unsupported firmware endianness\n");
+		return -EILSEQ;
+	}
+
+	if (size < ehdr->e_shoff + sizeof(Elf32_Shdr)) {
+		pr_debug("Image is too small\n");
+		return -ENOSPC;
+	}
+
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
+		pr_debug("Image is corrupted (bad magic)\n");
+		return -EBADF;
+	}
+
+	if (ehdr->e_phnum == 0) {
+		pr_debug("No loadable segments\n");
+		return -ENOEXEC;
+	}
+
+	if (ehdr->e_phoff > size) {
+		pr_debug("Firmware size is too small\n");
+		return -ENOSPC;
+	}
+
+	return 0;
+}
+
+/* A very simple elf loader, assumes the image is valid */
+int rproc_elf32_load_image(struct udevice *dev, unsigned long addr)
+{
+	Elf32_Ehdr *ehdr; /* Elf header structure pointer */
+	Elf32_Phdr *phdr; /* Program header structure pointer */
+	const struct dm_rproc_ops *ops;
+	unsigned int i;
+
+	ehdr = (Elf32_Ehdr *)addr;
+	phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);
+
+	ops = rproc_get_ops(dev);
+
+	/* Load each program header */
+	for (i = 0; i < ehdr->e_phnum; ++i) {
+		void *dst = (void *)(uintptr_t)phdr->p_paddr;
+		void *src = (void *)addr + phdr->p_offset;
+
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		if (ops->device_to_virt)
+			dst = ops->device_to_virt(dev, (ulong)dst);
+
+		dev_dbg(dev, "Loading phdr %i to 0x%p (%i bytes)\n",
+			i, dst, phdr->p_filesz);
+		if (phdr->p_filesz)
+			memcpy(dst, src, phdr->p_filesz);
+		if (phdr->p_filesz != phdr->p_memsz)
+			memset(dst + phdr->p_filesz, 0x00,
+			       phdr->p_memsz - phdr->p_filesz);
+		flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
+			    roundup((unsigned long)dst + phdr->p_filesz,
+				    ARCH_DMA_MINALIGN) -
+			    rounddown((unsigned long)dst, ARCH_DMA_MINALIGN));
+		++phdr;
+	}
+
+	return 0;
+}
diff --git a/drivers/remoteproc/sandbox_testproc.c b/drivers/remoteproc/sandbox_testproc.c
index 51a67e6bf1..5f35119ab7 100644
--- a/drivers/remoteproc/sandbox_testproc.c
+++ b/drivers/remoteproc/sandbox_testproc.c
@@ -8,6 +8,7 @@
 #include <dm.h>
 #include <errno.h>
 #include <remoteproc.h>
+#include <asm/io.h>
 
 /**
  * enum sandbox_state - different device states
@@ -300,6 +301,23 @@ static int sandbox_testproc_ping(struct udevice *dev)
 	return ret;
 }
 
+#define SANDBOX_RPROC_DEV_TO_PHY_OFFSET	0x1000
+/**
+ * sandbox_testproc_device_to_virt() - Convert device address to virtual address
+ * @dev:	device to operate upon
+ * @da:		device address
+ * @return converted virtual address
+ */
+static void *sandbox_testproc_device_to_virt(struct udevice *dev, ulong da)
+{
+	u64 paddr;
+
+	/* Use a simple offset conversion */
+	paddr = da + SANDBOX_RPROC_DEV_TO_PHY_OFFSET;
+
+	return phys_to_virt(paddr);
+}
+
 static const struct dm_rproc_ops sandbox_testproc_ops = {
 	.init = sandbox_testproc_init,
 	.reset = sandbox_testproc_reset,
@@ -308,6 +326,7 @@ static const struct dm_rproc_ops sandbox_testproc_ops = {
 	.stop = sandbox_testproc_stop,
 	.is_running = sandbox_testproc_is_running,
 	.ping = sandbox_testproc_ping,
+	.device_to_virt = sandbox_testproc_device_to_virt,
 };
 
 static const struct udevice_id sandbox_ids[] = {