git: 1066a70e149a - main - kboot: Need to find the ACPI tables

The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=1066a70e149abb383c49a4587de21eebf9b7e1d5

commit 1066a70e149abb383c49a4587de21eebf9b7e1d5
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2022-12-09 04:56:06 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2022-12-09 04:57:31 +0000

    kboot: Need to find the ACPI tables
    
    We need to pass the ACPI tables to the laucnhed kernel (at least for x86
    and aarch64). Find it using the Linux standard way.
    
    Sponsored by:           Netflix
---
 stand/kboot/kboot.h |  3 +++
 stand/kboot/main.c  | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/stand/kboot/kboot.h b/stand/kboot/kboot.h
index e3d169ee5ac0..72be7299995b 100644
--- a/stand/kboot/kboot.h
+++ b/stand/kboot/kboot.h
@@ -9,6 +9,9 @@
 
 #define DEVT_HOSTDISK 1234
 
+bool has_acpi(void);
+vm_offset_t acpi_rsdp(void);
+
 void do_init(void);
 
 extern const char *hostfs_root;
diff --git a/stand/kboot/main.c b/stand/kboot/main.c
index 2bbe14d79253..88657d908b34 100644
--- a/stand/kboot/main.c
+++ b/stand/kboot/main.c
@@ -102,6 +102,50 @@ parse_args(int argc, const char **argv)
 	return (howto);
 }
 
+static vm_offset_t rsdp;
+
+static vm_offset_t
+kboot_rsdp_from_efi(void)
+{
+	char buffer[512 + 1];
+	char *walker, *ep;
+
+	if (!file2str("/sys/firmware/efi/systab", buffer, sizeof(buffer)))
+		return (0);	/* Not an EFI system */
+	ep = buffer + strlen(buffer);
+	walker = buffer;
+	while (walker < ep) {
+		if (strncmp("ACPI20=", walker, 7) == 0)
+			return((vm_offset_t)strtoull(walker + 7, NULL, 0));
+		if (strncmp("ACPI=", walker, 5) == 0)
+			return((vm_offset_t)strtoull(walker + 5, NULL, 0));
+		walker += strcspn(walker, "\n");
+	}
+	return (0);
+}
+
+static void
+find_acpi()
+{
+	rsdp = kboot_rsdp_from_efi();
+#if 0	/* maybe for amd64 */
+	if (rsdp == 0)
+		rsdp = find_rsdp_arch();
+#endif
+}
+
+vm_offset_t
+acpi_rsdp()
+{
+	return (rsdp);
+}
+
+bool
+has_acpi()
+{
+	return rsdp != 0;
+}
+
 int
 main(int argc, const char **argv)
 {
@@ -146,6 +190,11 @@ main(int argc, const char **argv)
 	setenv("LINES", "24", 1);
 	setenv("usefdt", "1", 1);
 
+	/*
+	 * Find acpi, if it exists
+	 */
+	find_acpi();
+
 	interact();			/* doesn't return */
 
 	return (0);