This change allows seabios to load bootorder not only from CBFS but
also from the NVRAM as well, making use of coreboot's cmos.layout.
Tested on QEMU Q35
>From 055a831ed9872b99bf6d060c70b495e286ded1ba Mon Sep 17 00:00:00 2001
From: Timothy Kenno Handojo <timken...@mailbox.org>
Date: Thu, 31 Oct 2024 08:11:38 +0700
Subject: [PATCH] boot: Allow setting bootorder from CMOS entry
The original bootorder from CBFS remains, but takes lower priority.
Signed-off-by: Timothy Kenno Handojo <timken...@mailbox.org>
---
Makefile | 2 +-
src/boot.c | 9 +++-
src/nvram.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++
src/nvram.h | 37 +++++++++++++++
4 files changed, 176 insertions(+), 2 deletions(-)
create mode 100644 src/nvram.c
create mode 100644 src/nvram.h
diff --git a/Makefile b/Makefile
index d3341870..48f0b9ac 100644
--- a/Makefile
+++ b/Makefile
@@ -46,7 +46,7 @@ SRC32FLAT=$(SRCBOTH) post.c e820map.c malloc.c
romfile.c x86.c \
fw/mtrr.c fw/xen.c fw/acpi.c fw/mptable.c fw/pirtable.c \
fw/smbios.c fw/romfile_loader.c fw/dsdt_parser.c hw/virtio-ring.c \
hw/virtio-pci.c hw/virtio-mmio.c hw/virtio-blk.c hw/virtio-scsi.c \
- hw/tpm_drivers.c hw/nvme.c sha256.c sha512.c
+ hw/tpm_drivers.c hw/nvme.c sha256.c sha512.c nvram.c
SRC32SEG=string.c output.c pcibios.c apm.c stacks.c hw/pci.c hw/serialio.c
DIRS=src src/hw src/fw vgasrc
diff --git a/src/boot.c b/src/boot.c
index 1effd802..0689d7de 100644
--- a/src/boot.c
+++ b/src/boot.c
@@ -21,6 +21,8 @@
#include "string.h" // memset
#include "util.h" // irqtimer_calc
#include "tcgbios.h" // tpm_*
+#include "nvram.h" // get_nvram_bootorder
+
/****************************************************************
* Helper search functions
@@ -250,8 +252,13 @@ loadBootOrder(void)
{
if (!CONFIG_BOOTORDER)
return;
+ char *f = NULL;
+
+ f = get_nvram_bootorder();
+
+ if (!f)
+ f = romfile_loadfile("bootorder", NULL);
- char *f = romfile_loadfile("bootorder", NULL);
if (!f)
return;
diff --git a/src/nvram.c b/src/nvram.c
new file mode 100644
index 00000000..0634cf9c
--- /dev/null
+++ b/src/nvram.c
@@ -0,0 +1,130 @@
+#include "nvram.h"
+#include "string.h" // memcmp, strlen
+#include "malloc.h" // malloc_low
+#include "x86.h" // inb, outb
+#include "output.h" // dprintf
+#include "util.h" // cb_header, find_cb_table, find_cb_subtable
+
+#define CB_TAG_CMOS_OPTION_TABLE 0x00c8
+#define CB_TAG_OPTION 0x00c9
+#define CB_TAG_OPTION_CHECKSUM 0x00cc
+
+
+u8 nvram_read(u8 addr){
+ u16 rtc_port = addr < 128 ? RTC_PORT_STANDARD : RTC_PORT_EXTENDED;
+
+ outb(addr, rtc_port);
+ return inb(rtc_port + 1);
+}
+
+void nvram_write(u8 val, u8 addr)
+{
+ u16 rtc_port = addr < 128 ? RTC_PORT_STANDARD : RTC_PORT_EXTENDED;
+
+ outb(addr, rtc_port);
+ outb(val, rtc_port + 1);
+}
+
+struct nvram_accessor {
+ u8 (*read)(u8 reg);
+ void (*write)(u8 val, u8 reg);
+};
+
+struct nvram_accessor *use_nvram = &(struct nvram_accessor) {
+ nvram_read,
+ nvram_write
+};
+
+static struct cb_cmos_entries *lookup_cmos_entry(struct
cb_cmos_option_table *option_table, const char *name)
+{
+ struct cb_cmos_entries *cmos_entry, *next;
+ int len = name ? strlen(name) : 0;
+
+ /* CMOS entries are located right after the option table */
+ cmos_entry = (struct cb_cmos_entries*)((unsigned char
*)option_table + option_table->header_length);
+ while (cmos_entry) {
+ if (memcmp((const char*)cmos_entry->name, name, len) == 0)
+ return cmos_entry;
+ next = (struct cb_cmos_entries*)((unsigned char *)cmos_entry
+ cmos_entry->size);
+ cmos_entry = (next->tag == CB_TAG_OPTION) ? next : NULL;
+ }
+
+ dprintf(1, "ERROR: No such CMOS option (%s)\n", name);
+ return NULL;
+}
+
+static int get_cmos_value(const struct nvram_accessor *nvram, u32
bitnum, u32 len, void *valptr)
+{
+ u8 *value = valptr;
+ int offs = 0;
+ u32 addr, bit;
+ u8 reg8;
+
+ /* Convert to byte borders */
+ addr=(bitnum / 8);
+ bit=(bitnum % 8);
+
+ /* Handle single byte or less */
+ if(len <= 8) {
+ reg8 = nvram->read(addr);
+ reg8 >>= bit;
+ value[0] = reg8 & ((1 << len) -1);
+ return 0;
+ }
+
+ /* When handling more than a byte, copy whole bytes */
+ while (len > 0) {
+ len -= 8;
+ value[offs++]=nvram->read(addr++);
+ }
+
+ return 0;
+}
+
+int options_checksum_valid(const struct nvram_accessor *nvram, struct
cb_cmos_checksum *option_checksum)
+{
+ int i;
+ int checksum_location = option_checksum->location / 8;
+ u16 checksum = 0, checksum_old;
+
+ for(i = option_checksum->range_start; i <=
option_checksum->range_end; i++) {
+ checksum += nvram->read(i);
+ }
+
+ checksum_old = ((nvram->read(checksum_location)<<8) |
nvram->read(checksum_location+1));
+
+ return (checksum_old == checksum);
+}
+
+void *get_nvram_bootorder()
+{
+ const char *name = "bootorder";
+ struct cb_header *cbh = find_cb_table();
+
+ if (!cbh)
+ return NULL;
+ struct cb_cmos_option_table *option_table = find_cb_subtable(cbh,
CB_TAG_CMOS_OPTION_TABLE);
+ struct cb_cmos_checksum *option_checksum = find_cb_subtable(cbh,
CB_TAG_OPTION_CHECKSUM);
+ if (option_table == NULL) {
+ dprintf(1, "Could not find coreboot option table.\n");
+ return NULL;
+ }
+
+ struct cb_cmos_entries *cmos_entry = lookup_cmos_entry(option_table, name);
+
+ if (!cmos_entry)
+ return NULL;
+ int cmos_length = cmos_entry->length;
+
+ /* extra byte to ensure 0-terminated strings */
+ void *buf = malloc_low(cmos_length+1);
+ memset(buf, 0, cmos_length+1);
+
+ if(!options_checksum_valid(use_nvram, option_checksum)) {
+ dprintf(1, "Invalid option checksum.\n");
+ return NULL;
+ }
+ get_cmos_value(use_nvram, cmos_entry->bit, cmos_entry->length, buf);
+
+ return buf;
+}
diff --git a/src/nvram.h b/src/nvram.h
new file mode 100644
index 00000000..4c9d559e
--- /dev/null
+++ b/src/nvram.h
@@ -0,0 +1,37 @@
+#ifndef __NVRAM_H
+#define __NVRAM_H
+
+#include "types.h" // u32, u8
+
+#define RTC_PORT_STANDARD 0x70
+#define RTC_PORT_EXTENDED 0x72
+
+struct cb_cmos_option_table {
+ u32 tag;
+ u32 size;
+ u32 header_length;
+};
+
+#define CB_CMOS_MAX_NAME_LENGTH 32
+struct cb_cmos_entries {
+ u32 tag;
+ u32 size;
+ u32 bit;
+ u32 length;
+ u32 config;
+ u32 config_id;
+ u8 name[CB_CMOS_MAX_NAME_LENGTH];
+};
+
+struct cb_cmos_checksum {
+ u32 tag;
+ u32 size;
+ u32 range_start;
+ u32 range_end;
+ u32 location;
+ u32 type;
+};
+
+void *get_nvram_bootorder();
+
+#endif
\ No newline at end of file
--
2.39.5
_______________________________________________
SeaBIOS mailing list -- seabios@seabios.org
To unsubscribe send an email to seabios-le...@seabios.org
