Shamelessly steal the Linux x86 crash handling code and shove it into U-Boot (cool - it fits). Be sure to include suitable attribution to Linus --- This patch also fixed the annoyance of adding an extra 3 bytes per IRQ handler. I _really_ like this patch - It has probably been the single most useful patch as it adds the ability to use int3 to help debugging
cpu/i386/interrupts.c | 310 ++++++++++++++++++++++++++++++++++++------------- 1 files changed, 228 insertions(+), 82 deletions(-)
diff --git a/cpu/i386/interrupts.c b/cpu/i386/interrupts.c index 4b57437..2eae5be 100644 --- a/cpu/i386/interrupts.c +++ b/cpu/i386/interrupts.c @@ -5,6 +5,9 @@ * (C) Copyright 2002 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se. * + * Portions of this file are derived from the Linux kernel source + * Copyright (C) 1991, 1992 Linus Torvalds + * * See file CREDITS for list of people who contributed to this * project. * @@ -32,12 +35,112 @@ ".hidden irq_"#x"\n" \ ".type irq_"#x", @function\n" \ "irq_"#x":\n" \ - "pushl %ebp\n" \ - "movl %esp,%ebp\n" \ - "pusha\n" \ "pushl $"#x"\n" \ "jmp irq_common_entry\n"
+/* + * Volatile isn't enough to prevent the compiler from reordering the + * read/write functions for the control registers and messing everything up. + * A memory clobber would solve the problem, but would prevent reordering of + * all loads stores around it, which can hurt performance. Solution is to + * use a variable and mimic reads and writes to it to enforce serialization + */ +static unsigned long __force_order; + +static inline unsigned long read_cr0(void) +{ + unsigned long val; + asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline unsigned long read_cr2(void) +{ + unsigned long val; + asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline unsigned long read_cr3(void) +{ + unsigned long val; + asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline unsigned long read_cr4(void) +{ + unsigned long val; + asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline unsigned long get_debugreg(int regno) +{ + unsigned long val = 0; /* Damn you, gcc! */ + + switch (regno) { + case 0: + asm("mov %%db0, %0" :"=r" (val)); + break; + case 1: + asm("mov %%db1, %0" :"=r" (val)); + break; + case 2: + asm("mov %%db2, %0" :"=r" (val)); + break; + case 3: + asm("mov %%db3, %0" :"=r" (val)); + break; + case 6: + asm("mov %%db6, %0" :"=r" (val)); + break; + case 7: + asm("mov %%db7, %0" :"=r" (val)); + break; + default: + val = 0; + } + return val; +} + +void dump_regs(struct pt_regs *regs) +{ + unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L; + unsigned long d0, d1, d2, d3, d6, d7; + + printf("EIP: %04x:[<%08lx>] EFLAGS: %08lx\n", + (u16)regs->xcs, regs->eip, regs->eflags); + + printf("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n", + regs->eax, regs->ebx, regs->ecx, regs->edx); + printf("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n", + regs->esi, regs->edi, regs->ebp, regs->esp); + printf(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n", + (u16)regs->xds, (u16)regs->xes, (u16)regs->xfs, (u16)regs->xgs, (u16)regs->xss); + + cr0 = read_cr0(); + cr2 = read_cr2(); + cr3 = read_cr3(); + cr4 = read_cr4(); + + printf("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", + cr0, cr2, cr3, cr4); + + d0 = get_debugreg(0); + d1 = get_debugreg(1); + d2 = get_debugreg(2); + d3 = get_debugreg(3); + + printf("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n", + d0, d1, d2, d3); + + d6 = get_debugreg(6); + d7 = get_debugreg(7); + printf("DR6: %08lx DR7: %08lx\n", + d6, d7); +} + struct idt_entry { u16 base_low; u16 selector; @@ -122,7 +225,7 @@ int disable_interrupts(void) }
/* IRQ Low-Level Service Routine */ -__isr__ irq_llsr(int ip, int seg, int irq) +__isr__ irq_llsr(struct pt_regs *regs) { /* * For detailed description of each exception, refer to: @@ -131,74 +234,93 @@ __isr__ irq_llsr(int ip, int seg, int irq) * Order Number: 253665-029US, November 2008 * Table 6-1. Exceptions and Interrupts */ - switch (irq) { - case 0x00: - printf("Divide Error (Division by zero) at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x01: - printf("Debug Interrupt (Single step) at %04x:%08x\n", seg, ip); - break; - case 0x02: - printf("NMI Interrupt at %04x:%08x\n", seg, ip); - break; - case 0x03: - printf("Breakpoint at %04x:%08x\n", seg, ip); - break; - case 0x04: - printf("Overflow at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x05: - printf("BOUND Range Exceeded at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x06: - printf("Invalid Opcode (UnDefined Opcode) at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x07: - printf("Device Not Available (No Math Coprocessor) at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x08: - printf("Double fault at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x09: - printf("Co-processor segment overrun at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x0a: - printf("Invalid TSS at %04x:%08x\n", seg, ip); - break; - case 0x0b: - printf("Segment Not Present at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x0c: - printf("Stack Segment Fault at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x0d: - printf("General Protection at %04x:%08x\n", seg, ip); - break; - case 0x0e: - printf("Page fault at %04x:%08x\n", seg, ip); - while(1); - break; - case 0x0f: - printf("Floating-Point Error (Math Fault) at %04x:%08x\n", seg, ip); - break; - case 0x10: - printf("Alignment check at %04x:%08x\n", seg, ip); - break; - case 0x11: - printf("Machine Check at %04x:%08x\n", seg, ip); - break; - case 0x12: - printf("SIMD Floating-Point Exception at %04x:%08x\n", seg, ip); - break; + switch (regs->orig_eax) { + case 0x00: + printf("Divide Error (Division by zero)\n"); + dump_regs(regs); + while(1); + break; + case 0x01: + printf("Debug Interrupt (Single step)\n"); + dump_regs(regs); + break; + case 0x02: + printf("NMI Interrupt\n"); + dump_regs(regs); + break; + case 0x03: + printf("Breakpoint\n"); + dump_regs(regs); + break; + case 0x04: + printf("Overflow\n"); + dump_regs(regs); + while(1); + break; + case 0x05: + printf("BOUND Range Exceeded\n"); + dump_regs(regs); + while(1); + break; + case 0x06: + printf("Invalid Opcode (UnDefined Opcode)\n"); + dump_regs(regs); + while(1); + break; + case 0x07: + printf("Device Not Available (No Math Coprocessor)\n"); + dump_regs(regs); + while(1); + break; + case 0x08: + printf("Double fault\n"); + dump_regs(regs); + while(1); + break; + case 0x09: + printf("Co-processor segment overrun\n"); + dump_regs(regs); + while(1); + break; + case 0x0a: + printf("Invalid TSS\n"); + dump_regs(regs); + break; + case 0x0b: + printf("Segment Not Present\n"); + dump_regs(regs); + while(1); + break; + case 0x0c: + printf("Stack Segment Fault\n"); + dump_regs(regs); + while(1); + break; + case 0x0d: + printf("General Protection\n"); + dump_regs(regs); + break; + case 0x0e: + printf("Page fault\n"); + dump_regs(regs); + while(1); + break; + case 0x0f: + printf("Floating-Point Error (Math Fault)\n"); + dump_regs(regs); + break; + case 0x10: + printf("Alignment check\n"); + dump_regs(regs); + break; + case 0x11: + printf("Machine Check\n"); + dump_regs(regs); + break; + case 0x12: + printf("SIMD Floating-Point Exception\n"); + dump_regs(regs); + break; case 0x13: case 0x14: case 0x15: @@ -212,12 +334,13 @@ __isr__ irq_llsr(int ip, int seg, int irq) case 0x1d: case 0x1e: case 0x1f: - printf("Reserved Exception %d at %04x:%08x\n", irq, seg, ip); + printf("Reserved Exception\n"); + dump_regs(regs); break;
default: /* Hardware or User IRQ */ - do_irq(irq); + do_irq(regs->orig_eax); } }
@@ -226,22 +349,45 @@ __isr__ irq_llsr(int ip, int seg, int irq) * fully relocatable code. * - The call to irq_llsr will be a relative jump * - The IRQ entries will be guaranteed to be in order - * It's a bit annoying that we need to waste 3 bytes per interrupt entry - * (total of 768 code bytes), but we MUST create a Stack Frame and this is - * the easiest way I could do it. Maybe it can be made better later. + * Interrupt entries are now very small (a push and a jump) but they are + * now slower (all registers pushed on stack which provides complete + * crash dumps in the low level handlers */ asm(".globl irq_common_entry\n" \ ".hidden irq_common_entry\n" \ ".type irq_common_entry, @function\n" \ "irq_common_entry:\n" \ - "pushl $0\n" \ - "pushl $0\n" \ + "cld\n" \ + "pushl %gs\n" \ + "pushl %fs\n" \ + "pushl %es\n" \ + "pushl %ds\n" \ + "pushl %eax\n" \ + "pushl %ebp\n" \ + "pushl %edi\n" \ + "pushl %esi\n" \ + "pushl %edx\n" \ + "pushl %ecx\n" \ + "pushl %ebx\n" \ + "mov %esp, %eax\n" \ + "pushl %ebp\n" \ + "movl %esp,%ebp\n" \ + "pushl %eax\n" \ "call irq_llsr\n" \ "popl %eax\n" \ - "popl %eax\n" \ - "popl %eax\n" \ - "popa\n" \ "leave\n"\ + "popl %ebx\n" \ + "popl %ecx\n" \ + "popl %edx\n" \ + "popl %esi\n" \ + "popl %edi\n" \ + "popl %ebp\n" \ + "popl %eax\n" \ + "popl %ds\n" \ + "popl %es\n" \ + "popl %fs\n" \ + "popl %gs\n" \ + "add $4, %esp\n" \ "iret\n" \ DECLARE_INTERRUPT(0) \ DECLARE_INTERRUPT(1) \