Index: arch/ia32/_link.ld =================================================================== --- arch/ia32/_link.ld (revision 93ca46f7db9fa7b986fd58472ab20b5b0321e051) +++ arch/ia32/_link.ld (revision da585a52045238cf4d613295769429747b2a4670) @@ -1,4 +1,3 @@ -/* - * ia32 linker script +/** IA-32 linker script * * kernel text Index: arch/ia32/src/asm.s =================================================================== --- arch/ia32/src/asm.s (revision 93ca46f7db9fa7b986fd58472ab20b5b0321e051) +++ arch/ia32/src/asm.s (revision da585a52045238cf4d613295769429747b2a4670) @@ -27,5 +27,5 @@ # -# very low and hardware-level functions +## very low and hardware-level functions .text @@ -54,6 +54,10 @@ .global memcmp -# -# set priority level high + +## Set priority level high +# +# Disable interrupts and return previous +# EFLAGS in EAX. +# cpu_priority_high: pushf @@ -61,7 +65,11 @@ cli ret - -# -# set priority level low + + +## Set priority level low +# +# Enable interrupts and return previous +# EFLAGS in EAX. +# cpu_priority_low: pushf @@ -70,6 +78,9 @@ ret -# -# restore priority level + +## Restore priority level +# +# Restore EFLAGS. +# cpu_priority_restore: push 4(%esp) @@ -77,5 +88,8 @@ ret -# return raw priority level +## Return raw priority level +# +# Return EFLAFS in EAX. +# cpu_priority_read: pushf @@ -83,4 +97,9 @@ ret + +## Halt the CPU +# +# Halt the CPU using HLT. +# cpu_halt: cpu_sleep: @@ -88,4 +107,9 @@ ret + +## Turn paging on +# +# Enable paging and write-back caching in CR0. +# paging_on: pushl %eax @@ -99,8 +123,18 @@ ret + +## Read CR3 +# +# Store CR3 in EAX. +# cpu_read_dba: movl %cr3,%eax ret + +## Write CR3 +# +# Set CR3. +# cpu_write_dba: pushl %eax @@ -110,8 +144,18 @@ ret + +## Read CR2 +# +# Store CR2 in EAX. +# cpu_read_cr2: movl %cr2,%eax ret + +## Enable local APIC +# +# Enable local APIC in MSR. +# enable_l_apic_in_msr: pusha @@ -126,4 +170,13 @@ ret + +## Declare interrupt handlers +# +# Declare interrupt handlers for n interrupt +# vectors starting at vector i. +# +# The handlers setup data segment registers +# and call trap_dispatcher(). +# .macro handler i n push %ebp @@ -170,4 +223,8 @@ +## I/O input (byte) +# +# Get a byte from I/O port and store it AL. +# inb: push %edx @@ -178,4 +235,9 @@ ret + +## I/O input (word) +# +# Get a word from I/O port and store it AX. +# inw: push %edx @@ -186,4 +248,9 @@ ret + +## I/O input (dword) +# +# Get a dword from I/O port and store it EAX. +# inl: push %edx @@ -194,4 +261,9 @@ ret + +## I/O output (byte) +# +# Send a byte to I/O port. +# outb: push %ebp @@ -207,4 +279,9 @@ ret + +## I/O output (word) +# +# Send a word to I/O port. +# outw: push %ebp @@ -220,4 +297,9 @@ ret + +## I/O output (dword) +# +# Send a dword to I/O port. +# outl: push %ebp @@ -233,4 +315,12 @@ ret + +## Copy memory +# +# Copy a given number of bytes (3rd argument) +# from the memory location defined by 1st argument +# to the memory location defined by 2nd argument. +# The memory areas cannot overlap. +# SRC=8 DST=12 @@ -252,4 +342,37 @@ ret + +## Fill memory with bytes +# +# Fill a given number of bytes (2nd argument) +# at memory defined by 1st argument with the +# byte value defined by 3rd argument. +# +DST=8 +CNT=12 +X=16 +memsetb: + push %ebp + movl %esp,%ebp + pusha + + cld + movl CNT(%ebp),%ecx + movl DST(%ebp),%edi + movl X(%ebp),%eax + + rep stosb %al,%es:(%edi) + + popa + pop %ebp + ret + + +## Fill memory with words +# +# Fill a given number of words (2nd argument) +# at memory defined by 1st argument with the +# word value defined by 3rd argument. +# DST=8 CNT=12 @@ -271,23 +394,12 @@ ret -DST=8 -CNT=12 -X=16 -memsetb: - push %ebp - movl %esp,%ebp - pusha - - cld - movl CNT(%ebp),%ecx - movl DST(%ebp),%edi - movl X(%ebp),%eax - - rep stosb %al,%es:(%edi) - - popa - pop %ebp - ret - + +## Compare memory regions for equality +# +# Compare a given number of bytes (3rd argument) +# at memory locations defined by 1st and 2nd argument +# for equality. If the bytes are equal, EAX contains +# 0. +# SRC=12 DST=16 Index: arch/ia32/src/context.s =================================================================== --- arch/ia32/src/context.s (revision 93ca46f7db9fa7b986fd58472ab20b5b0321e051) +++ arch/ia32/src/context.s (revision da585a52045238cf4d613295769429747b2a4670) @@ -36,6 +36,10 @@ .global fpu_lazy_context_restore + +## Save current CPU context # -# save context of this CPU +# Save CPU context to the kernel_context variable +# pointed by the 1st argument. Returns 1 in EAX. +# context_save: push %ebx @@ -59,7 +63,11 @@ incl %eax ret - + + +## Restore current CPU context # -# restore saved context on this CPU +# Restore CPU context from the kernel_context variable +# pointed by the 1st argument. Returns 0 in EAX. +# context_restore: movl 4(%esp),%eax # address of the kernel_context variable to restore context from @@ -78,4 +86,2 @@ xorl %eax,%eax # context_restore returns 0 ret - - Index: arch/ia32/src/cpuid.s =================================================================== --- arch/ia32/src/cpuid.s (revision 93ca46f7db9fa7b986fd58472ab20b5b0321e051) +++ arch/ia32/src/cpuid.s (revision da585a52045238cf4d613295769429747b2a4670) @@ -27,6 +27,4 @@ # -# -# CPU identification functions. # The code below just interfaces the CPUID instruction. # CPU recognition logic is contained in higher-level functions. @@ -38,4 +36,9 @@ .global rdtsc + +## Determine CPUID support +# +# Return 0 in EAX if CPUID is not support, 1 if supported. +# has_cpuid: push %ebx @@ -56,5 +59,16 @@ ret -# cpuid(__u32 cmd, struct cpu_info *info) + +## Get CPUID data +# +# This code is just an interfaces the CPUID instruction, CPU recognition +# logic is contained in higher-level functions. +# +# The C prototype is: +# void cpuid(__u32 cmd, struct cpu_info *info) +# +# @param cmd CPUID command. +# @param info Buffer to store CPUID output. +# cpuid: pushl %ebp Index: arch/ia32/src/userspace.c =================================================================== --- arch/ia32/src/userspace.c (revision 93ca46f7db9fa7b986fd58472ab20b5b0321e051) +++ arch/ia32/src/userspace.c (revision da585a52045238cf4d613295769429747b2a4670) @@ -34,4 +34,10 @@ #include + +/** Enter userspace + * + * Change CPU protection level to 3, enter userspace. + * + */ void userspace(void) { @@ -48,6 +54,6 @@ "iret" : : "i" (selector(UDATA_DES) | PL_USER), "i" (USTACK_ADDRESS+THREAD_STACK_SIZE-1000), "r" (pri), "i" (selector(UTEXT_DES) | PL_USER), "i" (UTEXT_ADDRESS)); - /* NOT REACHED */ - + + /* Unreachable */ for(;;); }