From 3227aa04a06569c08bca64707ac90e82580c2311 Mon Sep 17 00:00:00 2001
From: claudio <claudio@openbsd.org>
Date: Thu, 30 Dec 2021 08:12:23 +0000
Subject: [PATCH] Add back support for -B net -b bsd.rd which emulates a PXE
 install and results in an autoinstall. This can be used to quickly create new
 OpenBSD installs. OK dv@

---
 usr.sbin/vmd/loadfile.h     |  5 +++--
 usr.sbin/vmd/loadfile_elf.c | 26 ++++++++++++++++++++------
 usr.sbin/vmd/vm.c           |  4 ++--
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/usr.sbin/vmd/loadfile.h b/usr.sbin/vmd/loadfile.h
index 0630c9bd0ee..609d336bdee 100644
--- a/usr.sbin/vmd/loadfile.h
+++ b/usr.sbin/vmd/loadfile.h
@@ -1,5 +1,5 @@
 /*	$NetBSD: loadfile.h,v 1.1 1999/04/28 09:08:50 christos Exp $	 */
-/*	$OpenBSD: loadfile.h,v 1.15 2021/06/16 16:55:02 dv Exp $	 */
+/*	$OpenBSD: loadfile.h,v 1.16 2021/12/30 08:12:23 claudio Exp $	 */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -80,7 +80,8 @@
 #define PML2_PAGE 0x13000
 #define NPTE_PG (PAGE_SIZE / sizeof(uint64_t))
 
-int loadfile_elf(gzFile, struct vm_create_params *, struct vcpu_reg_state *);
+int	loadfile_elf(gzFile, struct vm_create_params *, struct vcpu_reg_state *,
+	    unsigned int);
 
 size_t mread(gzFile, paddr_t, size_t);
 
diff --git a/usr.sbin/vmd/loadfile_elf.c b/usr.sbin/vmd/loadfile_elf.c
index 7088792949b..57237278d25 100644
--- a/usr.sbin/vmd/loadfile_elf.c
+++ b/usr.sbin/vmd/loadfile_elf.c
@@ -1,5 +1,5 @@
 /* $NetBSD: loadfile.c,v 1.10 2000/12/03 02:53:04 tsutsui Exp $ */
-/* $OpenBSD: loadfile_elf.c,v 1.39 2021/05/04 10:48:51 dv Exp $ */
+/* $OpenBSD: loadfile_elf.c,v 1.40 2021/12/30 08:12:23 claudio Exp $ */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -118,7 +118,7 @@ static void setsegment(struct mem_segment_descriptor *, uint32_t,
 static int elf32_exec(gzFile, Elf32_Ehdr *, u_long *, int);
 static int elf64_exec(gzFile, Elf64_Ehdr *, u_long *, int);
 static size_t create_bios_memmap(struct vm_create_params *, bios_memmap_t *);
-static uint32_t push_bootargs(bios_memmap_t *, size_t);
+static uint32_t push_bootargs(bios_memmap_t *, size_t, bios_bootmac_t *);
 static size_t push_stack(uint32_t, uint32_t);
 static void push_gdt(void);
 static void push_pt_32(void);
@@ -264,13 +264,14 @@ push_pt_64(void)
  */
 int
 loadfile_elf(gzFile fp, struct vm_create_params *vcp,
-    struct vcpu_reg_state *vrs)
+    struct vcpu_reg_state *vrs, unsigned int bootdevice)
 {
 	int r, is_i386 = 0;
 	uint32_t bootargsz;
 	size_t n, stacksize;
 	u_long marks[MARK_MAX];
 	bios_memmap_t memmap[VMM_MAX_MEM_RANGES + 1];
+	bios_bootmac_t bm, *bootmac = NULL;
 
 	if ((r = gzread(fp, &hdr, sizeof(hdr))) != sizeof(hdr))
 		return 1;
@@ -301,8 +302,12 @@ loadfile_elf(gzFile fp, struct vm_create_params *vcp,
 	else
 		push_pt_64();
 
+	if (bootdevice == VMBOOTDEV_NET) {
+		bootmac = &bm;
+		memcpy(bootmac, vcp->vcp_macs[0], ETHER_ADDR_LEN);
+	}
 	n = create_bios_memmap(vcp, memmap);
-	bootargsz = push_bootargs(memmap, n);
+	bootargsz = push_bootargs(memmap, n, bootmac);
 	stacksize = push_stack(bootargsz, marks[MARK_END]);
 
 	vrs->vrs_gprs[VCPU_REGS_RIP] = (uint64_t)marks[MARK_ENTRY];
@@ -382,9 +387,9 @@ create_bios_memmap(struct vm_create_params *vcp, bios_memmap_t *memmap)
  *  The size of the bootargs
  */
 static uint32_t
-push_bootargs(bios_memmap_t *memmap, size_t n)
+push_bootargs(bios_memmap_t *memmap, size_t n, bios_bootmac_t *bootmac)
 {
-	uint32_t memmap_sz, consdev_sz, i;
+	uint32_t memmap_sz, consdev_sz, bootmac_sz, i;
 	bios_consdev_t consdev;
 	uint32_t ba[1024];
 
@@ -408,6 +413,15 @@ push_bootargs(bios_memmap_t *memmap, size_t n)
 	memcpy(&ba[i + 3], &consdev, sizeof(bios_consdev_t));
 	i += consdev_sz / sizeof(int);
 
+	if (bootmac) {
+		bootmac_sz = 3 * sizeof(int) + (sizeof(bios_bootmac_t) + 3) & ~3;
+		ba[i] = 0x7;   /* bootmac */
+		ba[i + 1] = bootmac_sz;
+		ba[i + 2] = bootmac_sz;
+		memcpy(&ba[i + 3], bootmac, sizeof(bios_bootmac_t));
+		i += bootmac_sz / sizeof(int);
+	} 
+
 	ba[i++] = 0xFFFFFFFF; /* BOOTARG_END */
 
 	write_mem(BOOTARGS_PAGE, ba, PAGE_SIZE);
diff --git a/usr.sbin/vmd/vm.c b/usr.sbin/vmd/vm.c
index b59e960454c..4c6c99f1133 100644
--- a/usr.sbin/vmd/vm.c
+++ b/usr.sbin/vmd/vm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm.c,v 1.66 2021/11/29 05:17:35 deraadt Exp $	*/
+/*	$OpenBSD: vm.c,v 1.67 2021/12/30 08:12:23 claudio Exp $	*/
 
 /*
  * Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
@@ -336,7 +336,7 @@ start_vm(struct vmd_vm *vm, int fd)
 			fatalx("failed to open kernel - exiting");
 
 		/* Load kernel image */
-		ret = loadfile_elf(fp, vcp, &vrs);
+		ret = loadfile_elf(fp, vcp, &vrs, vmc->vmc_bootdevice);
 
 		/*
 		 * Try BIOS as a fallback (only if it was provided as an image
-- 
2.20.1