drop cbfs experiment

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

5 files changed, 8 insertions, 194 deletions

diff --git a/Makefile b/Makefile
index 476436c..1ac923d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,5 @@
 obj-y = code16.o entry.o main.o string.o printf.o cstart.o fw_cfg.o
-obj-y += linuxboot.o malloc.o pflash.o cbfs.o tables.o hwsetup.o
-obj-y += pci.o
+obj-y += linuxboot.o malloc.o pflash.o tables.o hwsetup.o pci.o
 
 all-y = bios.bin
 all: $(all-y)
diff --git a/README b/README
index a180244..7f45a06 100644
--- a/README
+++ b/README
@@ -1,6 +1,6 @@
 A simple x86 firmware that can boot Linux.
 
-Most of QEMU's 500-700 ms startup time is spent:
+Most of QEMU's startup time is spent:
 
 * in the dynamic linker.  This can be reduced by 150 ms simply by
   compiling a stripped down QEMU:
@@ -17,10 +17,8 @@ Most of QEMU's 500-700 ms startup time is spent:
 
 * in the BIOS.  qboot saves another 150 ms.
 
-* in fw_cfg.  qboot can use the new DMA interface to fw_cfg from QEMU 2.7+.
-  Alternatively, kernel and initrd can be put in a CoreBoot cbfs image
-  stored in flash.  However, flash has a limit of 8 MB.  In either case
-  350 ms are saved, bringing the startup time down to 60 ms.
+* until QEMU 2.7+, in fw_cfg.  qboot uses the DMA interface which is pretty
+  much instantaneous.
 
 Compile qboot
 =============
@@ -39,26 +37,12 @@ The result will be a 64K file named bios.bin.
 Usage
 =====
 
-fw_cfg based example:
-
     $ qemu-kvm -bios bios.bin \
       -kernel /boot/vmlinuz-4.0.3-300.fc22.x86_64 \
       -serial mon:stdio -append 'console=ttyS0,115200,8n1'
 
-cbfs-based example (pflash isn't the definitive interface though):
-
-    $ dd if=/dev/zero of=boot.bin bs=4096 count=1
-    $ cbfstool cbfs.rom create -s 8128k -B boot.bin  -m x86 -o 0x1000
-    $ cbfstool cbfs.rom add -f /boot/vmlinuz-4.0.3-300.fc22.x86_64 -n vmlinuz -t raw
-    $ echo 'console=ttyS0,115200,8n1' > cmdline
-    $ cbfstool cbfs.rom add -f cmdline -n cmdline -t raw
-    $ qemu-kvm -drive if=pflash,file=bios.bin,readonly=on \
-        -drive if=pflash,file=cbfs.rom,readonly=on \
-        -serial mon:stdio
-
 TODO
 ====
 
 * SMBIOS tables
 * Add the possibility to configure out PIC and PCI bridge initialization
-* Possibly drop cbfs support, superseded by fw_cfg DMA
diff --git a/cbfs.c b/cbfs.c
deleted file mode 100644
index b4c235e..0000000
--- a/cbfs.c
+++ /dev/null
@@ -1,157 +0,0 @@
-#include "bios.h"
-#include "stdio.h"
-#include "ioport.h"
-#include "string.h"
-#include "bswap.h"
-#include "linuxboot.h"
-
-#define CBFS_HEADER_MAGIC    0x4F524243		// ORBC
-#define CBFS_HEADER_VERSION1 0x31313131
-#define CBFS_HEADER_VERSION2 0x31313132
-
-static const char file_magic[8] = "LARCHIVE";
-
-struct cbfs_header {
-    uint32_t magic;
-    uint32_t version;
-    uint32_t romsize;
-    uint32_t bootblocksize;
-    uint32_t align;
-    uint32_t offset;
-    uint32_t pad[2];
-} __attribute__((__packed__));
-
-struct cbfs_file_header {
-    char magic[8];
-    uint32_t len;
-    uint32_t type;
-    uint32_t checksum;
-    uint32_t offset;
-} __attribute__((__packed__));
-
-
-struct cbfs_file {
-	uint32_t size;
-	const char *buf;
-	char name[57];
-	struct cbfs_file *next;
-};
-
-static struct cbfs_file *files;
-
-static bool cbfs_setup(const char *base, size_t sz)
-{
-	uint32_t ofs;
-	struct cbfs_header hdr;
-	struct cbfs_file **pnext;
-	uint32_t align;
-       
-	ofs = sz + (intptr_t)(int32_t)ldl_le_p(base + sz - 4);
-	if (ofs >= sz - sizeof(struct cbfs_header) ||
-	    ldl_be_p(base + ofs) != CBFS_HEADER_MAGIC)
-		ofs = 0;
-
-	for (; ofs + sizeof(struct cbfs_header) < sz; ofs++) {
-		if (ldl_be_p(base + ofs) != CBFS_HEADER_MAGIC)
-			continue;
-		memcpy(&hdr, base + ofs, sizeof(hdr));
-		if (ldl_be_p(&hdr.version) != CBFS_HEADER_VERSION1 &&
-		    ldl_be_p(&hdr.version) != CBFS_HEADER_VERSION2)
-			continue;
-		break;
-	}
-
-	if (ofs + sizeof(struct cbfs_header) >= sz)
-		return false;
-
-	pnext = &files;
-	ofs = ldl_be_p(&hdr.offset);
-	align = ldl_be_p(&hdr.align);
-	while (ofs + sizeof(struct cbfs_file_header) < sz) {
-		struct cbfs_file_header fhdr;
-		struct cbfs_file *f;
-
-		memcpy(&fhdr, base + ofs, sizeof(fhdr));
-		if (memcmp(&fhdr.magic, file_magic, sizeof(file_magic)))
-			break;
-
-		f = malloc_fseg(sizeof(*f));
-		*pnext = f;
-
-		f->size = ldl_be_p(&fhdr.len);
-		f->buf = base + ofs + ldl_be_p(&fhdr.offset);
-		strcpy(f->name, base + ofs + sizeof(fhdr));
-		f->next = NULL;
-		pnext = &f->next;
-
-		ofs = f->buf + f->size - base;
-		ofs = (ofs + align - 1) & -align;
-	}
-	return files != NULL;
-}
-
-static struct cbfs_file *cbfs_file_find(const char *name)
-{
-	struct cbfs_file *f = files;
-
-	for (f = files; f; f = f->next)
-		if (!strcmp(name, f->name))
-			return f;
-
-	return NULL;
-}
-
-uint32_t cbfs_size(const char *name)
-{
-	struct cbfs_file *f = cbfs_file_find(name);
-	if (!f)
-		return 0;
-
-	return f->size;
-}
-
-void cbfs_read(const char *name, void *buf, size_t size, size_t skip)
-{
-	struct cbfs_file *f = cbfs_file_find(name);
-	if (!f)
-		panic();
-
-	if (skip > f->size)
-		return;
-	if (size + skip > f->size)
-		size = f->size - skip;
-	memcpy(buf, f->buf + skip, size);
-}
-
-bool cbfs_boot(void)
-{
-	struct linuxboot_args args;
-
-	args.vmlinuz_size = cbfs_size("vmlinuz");
-	if (!args.vmlinuz_size)
-		return false;
-
-	args.initrd_size = cbfs_size("initrd");
-	args.cmdline_size = cbfs_size("cmdline");
-
-	cbfs_read("vmlinuz", args.header, sizeof(args.header), 0);
-	if (!parse_bzimage(&args))
-		return false;
-
-	cbfs_read("vmlinuz", args.setup_addr, args.setup_size, 0);
-	cbfs_read("vmlinuz", args.kernel_addr, args.kernel_size, args.setup_size);
-
-	if (args.initrd_size)
-		cbfs_read("initrd", args.initrd_addr, args.initrd_size, 0);
-	if (args.cmdline_size)
-		cbfs_read("cmdline", args.cmdline_addr, args.cmdline_size, 0);
-
-	boot_bzimage(&args);
-	return true;
-}
-
-bool boot_from_cbfs(void *base, size_t sz)
-{
-	return cbfs_setup(base, sz) && cbfs_boot();
-}
-
diff --git a/include/bios.h b/include/bios.h
index df60c5a..12087f2 100644
--- a/include/bios.h
+++ b/include/bios.h
@@ -43,7 +43,6 @@ extern void setup_hw(void);
 extern bool setup_mmconfig(void);
 extern void extract_acpi(void);
 extern void boot_from_fwcfg(void);
-extern bool boot_from_cbfs(void *base, size_t sz);
 
 extern uint16_t e820_seg;
 extern uint32_t lowmem;
diff --git a/main.c b/main.c
index 8ac2a68..547712c 100644
--- a/main.c
+++ b/main.c
@@ -77,17 +77,6 @@ static void extract_e820(void)
 	e820_seg = ((uintptr_t) e820) >> 4;
 }
 
-static bool detect_cbfs_and_boot(void)
-{
-	size_t sz;
-	void *base = pflash_base(1, &sz);
-
-	if (!base)
-		return false;
-
-	return boot_from_cbfs(base, sz);
-}
-
 int __attribute__ ((section (".text.startup"))) main(void)
 {
 #ifdef BENCHMARK_HACK
@@ -95,8 +84,9 @@ int __attribute__ ((section (".text.startup"))) main(void)
 #endif
 	setup_hw();
 
-	// Now go to the F-segment: we need to move away from flash area
-	// in order to probe CBFS!
+	// Only the 16-bit trampoline for vmlinuz and the 16-bit interrupt
+	// handlers need to run from the F-segment, but keep things simple
+	// and jump there.  From this point we can modify global variables.
 	asm("ljmp $0x8, $1f; 1:");
 
 	have_mmconfig = setup_mmconfig();
@@ -106,7 +96,6 @@ int __attribute__ ((section (".text.startup"))) main(void)
 	extract_acpi();
 	extract_e820();
 	// extract_smbios();
-	if (!detect_cbfs_and_boot())
-		boot_from_fwcfg();
+	boot_from_fwcfg();
 	panic();
 }