[coreboot-gerrit] Patch set updated for coreboot: cbfstool: Extract payload in ELF

[Antonello Dettori (dev@dettori.io)]

Antonello Dettori (dev at dettori.io) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15139

-gerrit

commit b320e33516165a0ea913afb7c4e84a0f73a1d5d9
Author: Antonello Dettori <dettori.an at gmail.com>
Date:   Thu Jun 9 12:35:36 2016 +0200

    cbfstool: Extract payload in ELF
    
    Implement function that automatically converts a SELF payload,
    extracted from the CBFS, into an ELF file.
    
    The code has been tested on the following payloads:
    Working: SeaBIOS, nvramcui, coreinfo and tint
    Currently not working: grub
    
    Change-Id: I51599e65419bfa4ada8fe24b119acb20c9936227
    Signed-off-by: Antonello Dettori <dettori.an at gmail.com>
---
 util/cbfstool/cbfs_image.c | 154 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 150 insertions(+), 4 deletions(-)

diff --git a/util/cbfstool/cbfs_image.c b/util/cbfstool/cbfs_image.c
index 0e20c80..4f88448 100644
--- a/util/cbfstool/cbfs_image.c
+++ b/util/cbfstool/cbfs_image.c
@@ -949,6 +949,149 @@ static int cbfs_stage_make_elf(struct buffer *buff, uint32_t arch)
 	return 0;
 }
 
+static int cbfs_payload_make_elf(struct buffer *buff, uint32_t arch)
+{
+	Elf64_Ehdr ehdr;
+	Elf64_Shdr shdr;
+	struct cbfs_payload_segment *segs = NULL;
+	struct elf_writer *ew;
+	struct buffer elf_out;
+	size_t empty_sz;
+	size_t payload_size;
+	int segments = 0;
+	char *payload_start_addr = NULL;
+
+	payload_start_addr = buff->data;
+	payload_size = buff->size;
+
+	/* Count the number of segments inside buffer */
+	while (true) {
+		uint32_t payload_type = 0;
+
+		memcpy(&payload_type, buff->data +
+				sizeof(struct cbfs_payload_segment) * segments,
+				sizeof(PAYLOAD_SEGMENT_CODE));
+
+		if (ntohl(payload_type) == PAYLOAD_SEGMENT_CODE) {
+			segments++;
+		} else if (ntohl(payload_type) == PAYLOAD_SEGMENT_DATA) {
+			segments++;
+		} else if (ntohl(payload_type) == PAYLOAD_SEGMENT_BSS) {
+			segments++;
+		} else if (ntohl(payload_type) == PAYLOAD_SEGMENT_PARAMS) {
+			segments++;
+		} else if (ntohl(payload_type) == PAYLOAD_SEGMENT_ENTRY) {
+			segments++;
+			break;
+		}
+
+	}
+
+	segs = malloc(segments * sizeof(*segs));
+
+	/* Decode xdr segments */
+	for (int i = 0; i < segments; i++) {
+		xdr_get_seg(&segs[i], (struct cbfs_payload_segment *)
+			(buff->data + i*sizeof(struct cbfs_payload_segment)));
+	}
+
+	if (init_elf_from_arch(&ehdr, arch))
+		return -1;
+
+	ehdr.e_entry = segs[segments-1].load_addr;
+
+	ew = elf_writer_init(&ehdr);
+	if (ew == NULL) {
+		ERROR("Unable to init ELF writer.\n");
+		return -1;
+	}
+
+	for (int i = 0; i < segments; i++) {
+		buff->data = payload_start_addr;
+		buff->size = payload_size;
+		memset(&shdr, 0, sizeof(shdr));
+		char *name = NULL;
+
+		if (segs[i].type == PAYLOAD_SEGMENT_CODE) {
+			shdr.sh_type = SHT_PROGBITS;
+			shdr.sh_flags = SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR;
+			shdr.sh_addr = segs[i].load_addr;
+			shdr.sh_size = segs[i].len;
+			empty_sz = segs[i].mem_len - segs[i].len;
+			name = strdup(".text");
+			buff->data += segs[i].offset;
+			buff->size = segs[i].len;
+
+		} else if (segs[i].type == PAYLOAD_SEGMENT_DATA) {
+			shdr.sh_type = SHT_PROGBITS;
+			shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
+			shdr.sh_addr = segs[i].load_addr;
+			shdr.sh_size = segs[i].len;
+			empty_sz = segs[i].mem_len - segs[i].len;
+			name = strdup(".data");
+			buff->data += segs[i].offset;
+			buff->size = segs[i].len;
+
+		} else if (segs[i].type == PAYLOAD_SEGMENT_BSS) {
+			shdr.sh_type = SHT_NOBITS;
+			shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
+			shdr.sh_addr = segs[i].load_addr;
+			shdr.sh_size = segs[i].len;
+			name = strdup(".bss");
+
+		} else if (segs[i].type == PAYLOAD_SEGMENT_PARAMS) {
+			shdr.sh_type = SHT_NOTE;
+			shdr.sh_flags = 0;
+			shdr.sh_size = segs[i].len;
+			name = strdup(".note.pinfo");
+			buff->data += segs[i].offset;
+			buff->size = segs[i].len;
+
+		} else if (segs[i].type == PAYLOAD_SEGMENT_ENTRY) {
+			continue;
+			break;
+		}
+
+
+		if (elf_writer_add_section(ew, &shdr, buff, name)) {
+			ERROR("Unable to add ELF section: %s\n", name);
+			elf_writer_destroy(ew);
+			return -1;
+		}
+
+		if (empty_sz != 0) {
+			struct buffer b;
+
+			buffer_init(&b, NULL, NULL, 0);
+			memset(&shdr, 0, sizeof(shdr));
+			shdr.sh_type = SHT_NOBITS;
+			shdr.sh_flags = SHF_WRITE | SHF_ALLOC;
+			shdr.sh_addr = segs[i].load_addr + segs[i].len;
+			shdr.sh_size = empty_sz;
+			if (elf_writer_add_section(ew, &shdr, &b, ".bss")) {
+				ERROR("Unable to add ELF section: .bss\n");
+				elf_writer_destroy(ew);
+				return -1;
+			}
+		}
+
+	}
+
+	if (elf_writer_serialize(ew, &elf_out)) {
+		ERROR("Unable to create ELF file from stage.\n");
+		elf_writer_destroy(ew);
+		return -1;
+	}
+
+	/* Flip buffer with the created ELF one. */
+	buffer_delete(buff);
+	*buff = elf_out;
+
+	elf_writer_destroy(ew);
+
+	return 0;
+}
+
 int cbfs_export_entry(struct cbfs_image *image, const char *entry_name,
 		      const char *filename, uint32_t arch)
 {
@@ -973,10 +1116,6 @@ int cbfs_export_entry(struct cbfs_image *image, const char *entry_name,
 	    entry_name, cbfs_get_entry_addr(image, entry),
 	    get_cbfs_entry_type_name(ntohl(entry->type)), decompressed_size);
 
-	if (ntohl(entry->type) == CBFS_COMPONENT_PAYLOAD) {
-		WARN("Payloads are extracted in SELF format.\n");
-	}
-
 	buffer_init(&buffer, strdup("(cbfs_export_entry)"), NULL, 0);
 
 	buffer.data = malloc(decompressed_size);
@@ -1001,6 +1140,13 @@ int cbfs_export_entry(struct cbfs_image *image, const char *entry_name,
 		}
 	}
 
+	if (ntohl(entry->type) == CBFS_COMPONENT_PAYLOAD) {
+		if (cbfs_payload_make_elf(&buffer, arch)) {
+			buffer_delete(&buffer);
+			return -1;
+		}
+	}
+
 	if (buffer_write_file(&buffer, filename) != 0) {
 		ERROR("Failed to write %s into %s.\n",
 		      entry_name, filename);