From fc00c656c96528112d05cf0edf8631bd5eaea446 Mon Sep 17 00:00:00 2001 From: Kacper Date: Sun, 7 Dec 2025 20:10:31 +0100 Subject: Add build system scaffolding and libc headers --- include/arch/x86_64/asm/debugreg.h | 100 +++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 include/arch/x86_64/asm/debugreg.h (limited to 'include/arch/x86_64/asm/debugreg.h') diff --git a/include/arch/x86_64/asm/debugreg.h b/include/arch/x86_64/asm/debugreg.h new file mode 100644 index 00000000..0e1c766a --- /dev/null +++ b/include/arch/x86_64/asm/debugreg.h @@ -0,0 +1,100 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _ASM_X86_DEBUGREG_H +#define _ASM_X86_DEBUGREG_H + +/* Indicate the register numbers for a number of the specific + debug registers. Registers 0-3 contain the addresses we wish to trap on */ +#define DR_FIRSTADDR 0 /* u_debugreg[DR_FIRSTADDR] */ +#define DR_LASTADDR 3 /* u_debugreg[DR_LASTADDR] */ + +#define DR_STATUS 6 /* u_debugreg[DR_STATUS] */ +#define DR_CONTROL 7 /* u_debugreg[DR_CONTROL] */ + +/* Define a few things for the status register. We can use this to determine + which debugging register was responsible for the trap. The other bits + are either reserved or not of interest to us. */ + +/* + * Define bits in DR6 which are set to 1 by default. + * + * This is also the DR6 architectural value following Power-up, Reset or INIT. + * + * Note, with the introduction of Bus Lock Detection (BLD) and Restricted + * Transactional Memory (RTM), the DR6 register has been modified: + * + * 1) BLD flag (bit 11) is no longer reserved to 1 if the CPU supports + * Bus Lock Detection. The assertion of a bus lock could clear it. + * + * 2) RTM flag (bit 16) is no longer reserved to 1 if the CPU supports + * restricted transactional memory. #DB occurred inside an RTM region + * could clear it. + * + * Apparently, DR6.BLD and DR6.RTM are active low bits. + * + * As a result, DR6_RESERVED is an incorrect name now, but it is kept for + * compatibility. + */ +#define DR6_RESERVED (0xFFFF0FF0) + +#define DR_TRAP0 (0x1) /* db0 */ +#define DR_TRAP1 (0x2) /* db1 */ +#define DR_TRAP2 (0x4) /* db2 */ +#define DR_TRAP3 (0x8) /* db3 */ +#define DR_TRAP_BITS (DR_TRAP0 | DR_TRAP1 | DR_TRAP2 | DR_TRAP3) + +#define DR_BUS_LOCK (0x800) /* bus_lock */ +#define DR_STEP (0x4000) /* single-step */ +#define DR_SWITCH (0x8000) /* task switch */ + +/* Now define a bunch of things for manipulating the control register. + The top two bytes of the control register consist of 4 fields of 4 + bits - each field corresponds to one of the four debug registers, + and indicates what types of access we trap on, and how large the data + field is that we are looking at */ + +#define DR_CONTROL_SHIFT 16 /* Skip this many bits in ctl register */ +#define DR_CONTROL_SIZE 4 /* 4 control bits per register */ + +#define DR_RW_EXECUTE (0x0) /* Settings for the access types to trap on */ +#define DR_RW_WRITE (0x1) +#define DR_RW_READ (0x3) + +#define DR_LEN_1 (0x0) /* Settings for data length to trap on */ +#define DR_LEN_2 (0x4) +#define DR_LEN_4 (0xC) +#define DR_LEN_8 (0x8) + +/* The low byte to the control register determine which registers are + enabled. There are 4 fields of two bits. One bit is "local", meaning + that the processor will reset the bit after a task switch and the other + is global meaning that we have to explicitly reset the bit. With linux, + you can use either one, since we explicitly zero the register when we enter + kernel mode. */ + +#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit */ +#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit */ +#define DR_LOCAL_ENABLE (0x1) /* Local enable for reg 0 */ +#define DR_GLOBAL_ENABLE (0x2) /* Global enable for reg 0 */ +#define DR_ENABLE_SIZE 2 /* 2 enable bits per register */ + +#define DR_LOCAL_ENABLE_MASK (0x55) /* Set local bits for all 4 regs */ +#define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */ + +/* The second byte to the control register has a few special things. + We can slow the instruction pipeline for instructions coming via the + gdt or the ldt if we want to. I am not sure why this is an advantage */ + +#ifdef __i386__ +#define DR_CONTROL_RESERVED (0xFC00) /* Reserved by Intel */ +#else +#define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00UL) /* Reserved */ +#endif + +#define DR_LOCAL_SLOWDOWN (0x100) /* Local slow the pipeline */ +#define DR_GLOBAL_SLOWDOWN (0x200) /* Global slow the pipeline */ + +/* + * HW breakpoint additions + */ + +#endif /* _ASM_X86_DEBUGREG_H */ -- cgit v1.2.3