From bf3d0660932584ec05ee6accb1411c984a1b59d1 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Wed, 11 Oct 2023 00:52:50 +0200
Subject: [PATCH] Add kernel(7) --firmware option.

---
 kernel/kernel.cpp       | 23 ++++++++++++++++++++++-
 kernel/kernelinfo.cpp   | 19 ++++++++-----------
 kernel/kernelinfo.h     |  1 +
 share/man/man7/kernel.7 |  9 +++++++++
 utils/kernelinfo.1      |  2 +-
 5 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/kernel/kernel.cpp b/kernel/kernel.cpp
index 5e9ccc46..63666966 100644
--- a/kernel/kernel.cpp
+++ b/kernel/kernel.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2018, 2021-2022 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2018, 2021-2023 Jonas 'Sortie' Termansen.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -233,6 +233,13 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo_p)
 
 	if ( !(kernel_options = strdup(cmdline ? cmdline : "")) )
 		Panic("Failed to allocate kernel command line");
+#if defined(__i386__) || defined(__x86_64__)
+	// TODO: Detect EFI.
+	kernel_firmware = "bios";
+#else
+	#warning "Name your system firmware here"
+	kernel_firmware = "unknown";
+#endif
 
 	int argmax = 1;
 	argv = new char*[argmax + 1];
@@ -288,6 +295,20 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo_p)
 			enable_network_drivers = true;
 		else if ( !strcmp(arg, "--no-random-seed") )
 			no_random_seed = true;
+		else if ( !strncmp(arg, "--firmware=", strlen("--firmware=")) )
+		{
+			const char* firmware = arg + strlen("--firmware=");
+#if defined(__i386__) || defined(__x86_64__)
+			if ( !strcmp(firmware, "bios") || !strcmp(firmware, "pc") )
+				kernel_firmware = "bios";
+			else if ( !strcmp(firmware, "efi") )
+				kernel_firmware = "efi";
+			else
+#endif
+			{
+				PanicF("Unsupported firmware option: %s", firmware);
+			}
+		}
 		else
 		{
 			Log::PrintF("\r\e[J");
diff --git a/kernel/kernelinfo.cpp b/kernel/kernelinfo.cpp
index 30899d55..a56f64fd 100644
--- a/kernel/kernelinfo.cpp
+++ b/kernel/kernelinfo.cpp
@@ -34,20 +34,17 @@
 namespace Sortix {
 
 char* kernel_options;
+const char* kernel_firmware;
 
 static const char* KernelInfo(const char* req)
 {
-	if ( strcmp(req, "name") == 0 ) { return BRAND_KERNEL_NAME; }
-	if ( strcmp(req, "version") == 0 ) { return VERSIONSTR; }
-	if ( strcmp(req, "tagline") == 0 ) { return BRAND_RELEASE_TAGLINE; }
-	if ( strcmp(req, "options") == 0 ) { return kernel_options; }
-	if ( strcmp(req, "builddate") == 0 ) { return __DATE__; }
-	if ( strcmp(req, "buildtime") == 0 ) { return __TIME__; }
-#if defined(__i386__) || defined(__x86_64__)
-	if ( strcmp(req, "firmware") == 0 ) { return "bios"; }
-#else
-	#warning "Name your system firmware here"
-#endif
+	if ( strcmp(req, "name") == 0 ) return BRAND_KERNEL_NAME;
+	if ( strcmp(req, "version") == 0 ) return VERSIONSTR;
+	if ( strcmp(req, "tagline") == 0 ) return BRAND_RELEASE_TAGLINE;
+	if ( strcmp(req, "options") == 0 ) return kernel_options;
+	if ( strcmp(req, "builddate") == 0 ) return __DATE__;
+	if ( strcmp(req, "buildtime") == 0 ) return __TIME__;
+	if ( strcmp(req, "firmware") == 0 ) return kernel_firmware;
 	return NULL;
 }
 
diff --git a/kernel/kernelinfo.h b/kernel/kernelinfo.h
index 1b49e77a..c0ecc406 100644
--- a/kernel/kernelinfo.h
+++ b/kernel/kernelinfo.h
@@ -23,6 +23,7 @@
 namespace Sortix {
 
 extern char* kernel_options;
+extern const char* kernel_firmware;
 
 } // namespace Sortix
 
diff --git a/share/man/man7/kernel.7 b/share/man/man7/kernel.7
index 29a4385d..ff9815ce 100644
--- a/share/man/man7/kernel.7
+++ b/share/man/man7/kernel.7
@@ -10,6 +10,7 @@
 .Op Fl \-enable-em
 .Op Fl \-disable-network-drivers
 .Op Fl \-enable-network-drivers
+.Op Fl \-firmware Ns = Ns Oo Sy bios "|" Sy efi "|" pc Oc
 .Op Fl \-no-random-seed
 .Op Fl \-
 .Op Ar init ...
@@ -64,6 +65,14 @@ driver.
 .It Fl \-enable-network-drivers
 Do initialize network drivers.
 This is the default behavior.
+.It Fl \-firmware Ns = Ns Oo Sy bios "|" Sy efi "|" pc Oc
+Informs the kernel the system is booted using
+.Sy bios or
+.Sy efi .
+The
+.Sy pc
+value is a synonym for
+.Sy bios .
 .It Fl \-no-random-seed
 Don't warn if no random seed file was loaded by the bootloader (usually from
 .Pa /boot/random.seed ) .
diff --git a/utils/kernelinfo.1 b/utils/kernelinfo.1
index f1fba49a..d864b285 100644
--- a/utils/kernelinfo.1
+++ b/utils/kernelinfo.1
@@ -30,7 +30,7 @@ The date on which the current kernel was built.
 .It Sy buildtime
 The time at which the current kernel was built.
 .It Sy firmware
-The firmware of the system (e.g. "bios" or "uefi")
+The firmware of the system (e.g. "bios" or "efi")
 .El
 .Sh EXIT STATUS
 .Nm