@@ -1,58 +1,60 @@ #=============================================================================== # 32-bit boot-agnostic kernel startup code / interrupt handlers #=============================================================================== -# 'ld -T cleese.ld' to generate a grub-bootable executable, then -# 'objcopy -O binary' that executable to get a bootp-bootable file. -#=============================================================================== + #------------------------------------------------------------------------------- # 'entry' should be the entry point for a grub kernel, and # placed at the start of the text section for a bootp kernel #------------------------------------------------------------------------------- + def entry(): """ takes control from the bootloader """ - db(0x0f,0x01,0x15) # use our descriptor table (lgdt [gdt]) + + db(0x0f,0x01,0x15) # use our descriptor table (lgdt [gdt]) dd(gdt) - - ax = 0x18 # load ds + + ax = 0x18 # load ds ds = ax; es = ax; ss = ax xor(ax,ax) fs = ax; gs = ax - - db(0xea) + + db(0xea) # load cs (jmp 10h:startC) dd(startC); dw(0x10) + def startC(): """ builds C environment and calls main() """ - + # set320x200x256 - + # esi = bootscreen # edi = 0xA0000 # ecx = 0x0FA00 # rep; movsb - - edi = bss # zero out BSS + + edi = bss # zero out BSS ecx = end ecx -= edi - ecx >>= 2 # (assume sections are word aligned) + ecx >>= 2 # (assume sections are word aligned) eax = 0 rep; stosl - - esp = resb(0x1000) # set up a stack - esp += 0x0ffc - + + esp = resb(0x1000) # set up a stack + esp += 0x0ffc + #---------------------------------------------- # TEMPORARY: busy wait to pause for boot screen # ecx = 0x80000000 # while dec(ecx) is nz: pass #---------------------------------------------- - + set80x25 + + main(ebx) # and call C code + dw(0xfeeb) # infinite loop (jmp $-2) - main(ebx) # and call C code - dw(0xfeeb) # infinite loop (jmp $-2) #------------------------------------------------------------------------------- # Multiboot header for GRUB bootloader. This must be in the first 8K @@ -60,97 +62,124 @@ def startC(): #------------------------------------------------------------------------------- align(4) - dd(0x1BADB002, # magic - 0x00010003, # AOUT_KLUDGE(16)|MEMORY_INFO(1)|PAGE_ALIGN(0) - 0xe4514ffb, # checksum: -(magic + flags) - entry, bss, end, - entry) + dd( 0x1BADB002, # magic + 0x00010003, # AOUT_KLUDGE(16)|MEMORY_INFO(1)|PAGE_ALIGN(0) + 0xe4514ffb, # checksum: -(magic + flags) + entry, bss, end, + entry ) -gdt = dw(0x20); dd(gdt); dw(0, # overlay: len + address +gdt = dw(0x20); dd(gdt); dw(0, # overlay: len + address 0, 0, 0, 0, - 0xffff,0,0x9a00, 0xcf, # flat code descriptor - 0xffff,0,0x9200, 0xcf) # flat data descriptor + 0xffff,0,0x9a00, 0xcf, # flat code descriptor + 0xffff,0,0x9200, 0xcf) # flat data descriptor + #=============================================================================== # spartan interrupt support #=============================================================================== + def initirqs(): """ initialize interrupts """ - db(0x0f,0x01,0x1d) # set up vectors (lidt [idt_desc]) + + db(0x0f,0x01,0x1d) # set up vectors (lidt [idt_desc]) dd(idt_desc) - sti # enable interrupts + sti # enable interrupts + #------------------------------------------------------------------------------- def ign(): """ ignored processor trap """ - db(0xcf) # (iret) + + db(0xcf) # (iret) + def bpt(): - cli; pusha + cli + pusha """ breakpoint """ ebx = [esp + 0x24] - printf("[%x: eax=%x]\n",ebx,eax) - popa; db(0xcf) + printf("[%x: eax=%x]\n", ebx, eax) + popa + db(0xcf) + #------------------------------------------------------------------------------- + def icoda(): """ common interrupt exit code """ + # clear the interrupt - al = 0x20 # EO1 - outb(0x20,al) # PIC1 - + al = 0x20 # EO1 + outb(0x20,al) # PIC1 + # restore the state esp += 4 popa - db(0xcf) # iret + db(0xcf) # iret + #------------------------------------------------------------------------------- + def igp(): """ ignored PIC interrupt """ - cli; pusha + + cli + pusha icoda + def clk(): """ clock tick """ - cli; pusha + + cli + pusha clickticker [isr_mask] |= 1 Py_AddPendingCall(python_isr, 0) icoda + def key(): """ keyboard """ - cli; pusha + + cli + pusha [isr_mask] |= 2 Py_AddPendingCall(python_isr, 0) icoda + def isrs_pending(): """ returns (and resets) the pending isr flag vector """ + cli eax = [isr_mask] xor(edx,edx) [isr_mask] = edx sti + #------------------------------------------------------------------------------- # due to the split offsets in the Intel interrupt table, # interrupt vectors must reside at 0x10:0x0010XXXX #------------------------------------------------------------------------------- + idt_desc = dw(0x7f); dd( dd(ign, 0x00108f00, ign, 0x00108f00, ign, 0x00108f00, bpt, 0x00108f00, - ign, 0x00108f00, ign, 0x00108f00, ign, 0x00108f00, ign, 0x00108f00, + ign, 0x00108f00, ign, 0x00108f00, ign, 0x00108f00, ign, 0x00108f00, + + clk, 0x00108f00, key, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00, + igp, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00)) - clk, 0x00108f00, key, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00, - igp, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00, igp, 0x00108f00)) #=============================================================================== + def clickticker(): edx = [ticker] if test(edx,edx) is nz: @@ -158,10 +187,12 @@ def clickticker(): inc(eax) [edx] = eax + #=============================================================================== # experimental: VGA graphics #=============================================================================== + def outn(): ebx = [esp + 16] xor(ecx,ecx) @@ -174,6 +205,7 @@ def outn(): outb(dx,al) inc(ecx) + def palette(): eax = [esp + 4] if test(eax,eax) is z: @@ -182,17 +214,19 @@ def palette(): else: eax = 0x20; edx = 0x3C0; outb(dx,al) + def sequenceron(): edx = 0x3C2; outb(dx, al) outn(0x3C4,0x3C5,1,db(3)) - + + def set640x480x16(): palette(0) - + outn(0x3C4,0x3C5,5,db(1,1,0x04,0,6)) - + eax = 0xe3; sequenceron - + eax = 0x11; edx =0x3D4; outb(dx,al) eax = 0; edx =0x3D5; outb(dx,al) outn(0x3D4,0x3D5,25,db( @@ -200,29 +234,29 @@ def set640x480x16(): 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xea, 0x8c, 0xdf, 0x28, 0x00, 0xe7, 0x04, 0xe3, 0xff)) - + outn(0x3CC,0x3CA,1,db(1)) outn(0x3CE,0x3CF,9,db( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x0f, 0xff)) - + edx = 0x3DA; inb(al, dx) - + outn(0x3C0,0x3C0,20,db( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x01, 0x00, 0x0F, 0x00)) - + palette(1) def set80x25(): palette(0) - + outn(0x3C4,0x3C5,5,db(1,0,0x03,0,2)) - + eax = 0x67; sequenceron - + eax = 0x11; edx =0x3D4; outb(dx,al) eax = 0; edx =0x3D5; outb(dx,al) outn(0x3D4,0x3D5,25,db( @@ -230,27 +264,28 @@ def set80x25(): 0x00, 0x4f, 0x0d, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x9c, 0x8e, 0x8f, 0x28, 0x1f, 0x96, 0xb9, 0xa3, 0xff)) - + outn(0x3CC,0x3CA,1,db(1)) outn(0x3CE,0x3CF,9,db( 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x0e, 0x00, 0xff)) - + edx = 0x3DA; inb(al, dx) outn(0x3C0,0x3C0,20,db( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x0C, 0x00, 0x0F, 0x08)) - + palette(1) + def set320x200x256(): palette(0) - + outn(0x3C4,0x3C5,5,db(3,1,0xf,0,0xe)) # .., 0x6) for mode X eax = 0x63; sequenceron - + eax = 0x11; edx =0x3D4; outb(dx,al) eax = 0; edx =0x3D5; outb(dx,al) outn(0x3D4,0x3D5,25,db( @@ -259,18 +294,18 @@ def set320x200x256(): 0x9c, 0x0e, 0x8f, 0x28, 0x40, 0x96, 0xb9, 0xa3, # 0x00, ..., 0xe3 for mode X 0xff)) - + outn(0x3CC,0x3CA,1,db(1)) outn(0x3CE,0x3CF,9,db( 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x05, 0x0f, 0xff)) - + edx = 0x3DA; inb(al, dx) outn(0x3C0,0x3C0,20,db( 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x41, 0x00, 0x0F, 0x00)) - + esi = paldata xor(ecx,ecx) while ecx < 256: @@ -279,15 +314,17 @@ def set320x200x256(): lodsb; edx = 0x3C9; outb(dx,al) lodsb; edx = 0x3C9; outb(dx,al) inc(ecx) - + palette(1) + def setrplane(): eax = 4 edx = 0x3CE; outb(dx,al) # VGA_GC_INDEX eax = [esp + 4] inc(edx); outb(dx,al) + def setwplane(): eax = 2 edx = 0x3C4; outb(dx,al) # VGA_SEQ_INDEX echo/kernel/kstart.boa @@ -1,43 +1,45 @@ #=============================================================================== # 32-bit boot-agnostic kernel startup code / interrupt handlers #=============================================================================== -# 'ld -T cleese.ld' to generate a grub-bootable executable, then -# 'objcopy -O binary' that executable to get a bootp-bootable file. -#=============================================================================== + #------------------------------------------------------------------------------- # 'entry' should be the entry point for a grub kernel, and # placed at the start of the text section for a bootp kernel #------------------------------------------------------------------------------- + def entry(): """ takes control from the bootloader """ - db(0x0f,0x01,0x15) # use our descriptor table (lgdt [gdt]) - dd(gdt) - - ax = 0x18 # load ds - ds = ax; es = ax; ss = ax + + db(0x0f,0x01,0x15) # use our descriptor table (lgdt [gdt]) + dd(gdt) + + ax = 0x18 # load ds + ds = ax; es = ax; ss = ax xor(ax,ax) fs = ax; gs = ax - - db(0xea) # load cs (jmp 10h:startC) + + db(0xea) # load cs (jmp 10h:startC) dd(startC); dw(0x10) + def startC(): """ builds C environment and calls main() """ + + edi = bss # zero out BSS + ecx = end + ecx -= edi + ecx >>= 2 # (assume sections are word aligned) + eax = 0 + rep; stosl + + esp = resb(0x1000) # set up a stack + esp += 0x0ffc + + Py_FrozenMain(ebx) # and call C code + dw(0xfeeb) # infinite loop (jmp $-2) - edi = bss # zero out BSS - ecx = end - ecx -= edi - ecx >>= 2 # (assume sections are word aligned) - eax = 0 - rep; stosl - - esp = resb(0x1000) # set up a stack - esp += 0x0ffc - - Py_FrozenMain(ebx) # and call C code - dw(0xfeeb) # infinite loop (jmp $-2) #------------------------------------------------------------------------------- # Multiboot header for GRUB bootloader. This must be in the first 8K @@ -45,16 +47,16 @@ def startC(): #------------------------------------------------------------------------------- align(4) - dd(0x1BADB002, # magic - 0x00010003, # AOUT_KLUDGE(16)|MEMORY_INFO(1)|PAGE_ALIGN(0) - 0xe4514ffb, # checksum: -(magic + flags) - offset(0xfffffff4), # address of bootblock start - entry, bss, end, - entry) - -gdt = dw(0x20); dd(gdt); dw(0, # overlay: len + address + dd( 0x1BADB002, # magic + 0x00010003, # AOUT_KLUDGE(16)|MEMORY_INFO(1)|PAGE_ALIGN(0) + 0xe4514ffb, # checksum: -(magic + flags) + offset(0xfffffff4), # address of bootblock start + entry, bss, end, + entry ) + +gdt = dw(0x20); dd(gdt); dw(0, # overlay: len + address 0, 0, 0, 0, - 0xffff,0,0x9a00, 0xcf, # flat code descriptor - 0xffff,0,0x9200, 0xcf) # flat data descriptor + 0xffff,0,0x9a00, 0xcf, # flat code descriptor + 0xffff,0,0x9200, 0xcf) # flat data descriptor #=============================================================================== necco/lib/bochs/crt0.boa de8ae5d9b59dbb57eb54463d481abf068641e34c James Tauber jtauber@jtauber.com http://github.com/jtauber/cleese/commit/e5f9e60701bc511667d241ee928367648a979ab7 e5f9e60701bc511667d241ee928367648a979ab7 2009-10-11T11:48:10-07:00 2009-10-11T11:48:10-07:00 more cleanup of code formatting d6807b9d40756c700410095be2b3b25f1dc806ec James Tauber jtauber@jtauber.com