From 557767f80294054932c7453be0e268ad39643fdc Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 27 Aug 2024 19:44:28 -0600 Subject: [PATCH] x86: Add a cpuid command It is useful to obtain the results of cpuid queries, so add a command for this. Signed-off-by: Simon Glass --- cmd/x86/Makefile | 2 +- cmd/x86/cpuid.c | 37 ++++++++++++++++++++++ doc/usage/cmd/cpuid.rst | 68 +++++++++++++++++++++++++++++++++++++++++ doc/usage/index.rst | 1 + test/cmd/Makefile | 1 + test/cmd/cpuid.c | 22 +++++++++++++ 6 files changed, 130 insertions(+), 1 deletion(-) create mode 100644 cmd/x86/cpuid.c create mode 100644 doc/usage/cmd/cpuid.rst create mode 100644 test/cmd/cpuid.c diff --git a/cmd/x86/Makefile b/cmd/x86/Makefile index b1f39d3bfd..1648907ac2 100644 --- a/cmd/x86/Makefile +++ b/cmd/x86/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0+ obj-$(CONFIG_CMD_CBSYSINFO) += cbsysinfo.o -obj-y += mtrr.o +obj-y += cpuid.o mtrr.o obj-$(CONFIG_CMD_EXCEPTION) += exception.o obj-$(CONFIG_USE_HOB) += hob.o obj-$(CONFIG_HAVE_FSP) += fsp.o diff --git a/cmd/x86/cpuid.c b/cmd/x86/cpuid.c new file mode 100644 index 0000000000..222754b5d1 --- /dev/null +++ b/cmd/x86/cpuid.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * The 'cpuid' command provides access to the CPU's cpuid information + * + * Copyright 2024 Google, LLC + * Written by Simon Glass + */ + +#include +#include +#include + +static int do_cpuid(struct cmd_tbl *cmdtp, int flag, int argc, + char *const argv[]) +{ + struct cpuid_result res; + ulong op; + + if (argc < 2) + return CMD_RET_USAGE; + + op = hextoul(argv[1], NULL); + res = cpuid(op); + printf("eax %08x\n", res.eax); + printf("ebx %08x\n", res.ebx); + printf("ecx %08x\n", res.ecx); + printf("edx %08x\n", res.edx); + + return 0; +} + +U_BOOT_LONGHELP(cpuid, "Show CPU Identification information"); + +U_BOOT_CMD( + cpuid, 2, 1, do_cpuid, + "cpuid ", cpuid_help_text +); diff --git a/doc/usage/cmd/cpuid.rst b/doc/usage/cmd/cpuid.rst new file mode 100644 index 0000000000..cccf9262ed --- /dev/null +++ b/doc/usage/cmd/cpuid.rst @@ -0,0 +1,68 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +.. index:: + single: cpuid (command) + +cpuid command +============= + +Synopsis +-------- + +:: + + cpuid + +Description +----------- + +The cpuid command requests CPU-identification information on x86 CPUs. The +operation selects what information is returned. Up to four 32-bit registers +can be update (eax-edx) depending on the operation. + +Configuration +------------- + +The cpuid command is only available on x86. + +Return value +------------ + +The return value $? is 0 (true). + +Example +------- + +:: + + => cpuid 1 + eax 00060fb1 + ebx 00040800 + ecx 80002001 + edx 178bfbfd + +This shows checking for 64-bit 'long' mode:: + + => cpuid 80000000 + eax 8000000a + ebx 68747541 + ecx 444d4163 + edx 69746e65 + => cpuid 80000001 + eax 00060fb1 + ebx 00000000 + ecx 00000007 + edx 2193fbfd # Bit 29 is set in edx, so long mode is available + +On a 32-bit-only CPU:: + + => cpuid 80000000 + eax 80000004 + ebx 756e6547 + ecx 6c65746e + edx 49656e69 + => cpuid 80000001 + eax 00000663 + ebx 00000000 + ecx 00000000 + edx 00000000 # Bit 29 is not set in edx, so long mode is not available diff --git a/doc/usage/index.rst b/doc/usage/index.rst index fcce125a61..d2b187b011 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -52,6 +52,7 @@ Shell commands cmd/conitrace cmd/cp cmd/cpu + cmd/cpuid cmd/cyclic cmd/dm cmd/ebtupdate diff --git a/test/cmd/Makefile b/test/cmd/Makefile index dbee9b2640..302c748389 100644 --- a/test/cmd/Makefile +++ b/test/cmd/Makefile @@ -12,6 +12,7 @@ ifdef CONFIG_CONSOLE_RECORD obj-$(CONFIG_CMD_PAUSE) += test_pause.o endif obj-y += exit.o mem.o +obj-$(CONFIG_X86) += cpuid.o obj-$(CONFIG_CMD_ADDRMAP) += addrmap.o obj-$(CONFIG_CMD_BDI) += bdinfo.o obj-$(CONFIG_CMD_FDT) += fdt.o diff --git a/test/cmd/cpuid.c b/test/cmd/cpuid.c new file mode 100644 index 0000000000..e07f5fd469 --- /dev/null +++ b/test/cmd/cpuid.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Tests for cpuid command + * + * Copyright 2024 Google LLC + * Written by Simon Glass + */ + +#include +#include + +static int cmd_test_cpuid(struct unit_test_state *uts) +{ + ut_assertok(run_commandf("cpuid 1")); + ut_assert_nextline("eax 00060fb1"); + ut_assert_nextline("ebx 00000800"); + ut_assert_nextline("ecx 80002001"); + ut_assert_nextline("edx 078bfbfd"); + + return 0; +} +CMD_TEST(cmd_test_cpuid, UTF_CONSOLE); -- 2.39.5