remove the dword stack macros and just use the 32bit override
This commit is contained in:
@@ -207,50 +207,6 @@ struc AddressRangeDescStruct_t
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.ExtType resd 1
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endstruc
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; moves argument into eax then pushes lower 16bits then upper 16 bits of of argument to stack
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; eax is clobbered
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%macro PUSH_DWORD 1
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mov eax, %1
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push ax
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shr eax, 16
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push ax
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%endmacro
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; same as PUSH_DWORD except no arguments, pushes EAX directly
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%macro PUSH_DWORD_EAX 0
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push ax
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shr eax, 16
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push ax
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%endmacro
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; pops upper 16bits then lower 16bits into eax
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; eax is clobbered
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%macro POP_DWORD_EAX 0
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xor eax, eax
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pop ax
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shl eax, 16
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pop ax
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%endmacro
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; moves data on stack referenced by bp to eax
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; stack must be organized as follows (tl;dr push lower 16bits first ie. PUSH_DWORD macro)
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; MOV_DWORD_EAX 2
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; STACK TOP (0x0)
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; upper_uint16 [bp-4]
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; lower_uint16 [bp-2]
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; --- [bp] ---
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; ...
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; STACK BOTTOM
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;
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; first argument == starting offset from bp for lower 16bits
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; BUG: needs fixed for cdecl16
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%macro MOV_DWORD_EAX 1
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mov ax, [bp+(%1+2)]
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shl eax, 16
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mov ax, [bp+%1]
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; eax contains dword from stack
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%endmacro
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%macro DEBUG_HCF 0
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DEBUG_LOOP:
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hlt
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@@ -110,14 +110,16 @@ main:
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; Find first cluster of bootable file
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;
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call SearchFATDIR
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PUSH_DWORD_EAX ; save return value of function as a 32-bit value on a 16-bit aligned stack
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push dword eax
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lea ax, [FileFound_OK_cstr]
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push ax
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call PrintString
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add sp, 0x2
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call PrintDWORD ; print 32bit value void PrintDWORD(uint32_t dword)
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push dword eax
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call PrintDWORD ; void PrintDWORD(uint32_t dword)
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add sp, 0x4
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lea ax, [NewLine_cstr]
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push ax
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@@ -194,12 +196,11 @@ InitFATDriver:
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SearchFATDIR:
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__CDECL16_ENTRY
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.file_lookup:
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xor ecx, ecx
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xor edx, edx
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.load_first_dir:
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mov eax, [fat32_ebpb + FAT32_ebpb_t.root_dir_cluster_32]
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mov dword [fat32_state + FAT32_State_t.active_dir_cluster_32], eax
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PUSH_DWORD_EAX
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push dword eax ; cluster
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lea ax, [dir_buffer]
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push ax ; offset
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xor ax, ax
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@@ -211,12 +212,11 @@ SearchFATDIR:
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jmp SearchFATDIR.empty_dir_entry
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.load_next_dir:
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; uint32_t NextCluster(uint32_t active_cluster);
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; if eax >= 0x0FFFFFF8 then there are no more clusters (end of chain)
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; if eax == 0x0FFFFFF7 then this is a cluster that is marked as bad
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mov eax, dword [fat32_state + FAT32_State_t.active_dir_cluster_32]
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PUSH_DWORD_EAX
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call NextCluster
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push dword eax
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call NextCluster ; uint32_t NextCluster(uint32_t active_cluster);
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add sp, 0x4
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cmp eax, 0x0fff_fff7
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@@ -226,12 +226,12 @@ SearchFATDIR:
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.load_next_dir_next_OK:
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; load 512 bytes of directory entries from data sector
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mov eax, [fat32_state + FAT32_State_t.active_dir_cluster_32]
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PUSH_DWORD_EAX
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lea ax, [dir_buffer]
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push dword eax
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lea ax, [dir_buffer] ; cluster
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push ax ; offset
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xor ax, ax
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push ax ; segment
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call ReadFATCluster ; uint8_t ReadFATCluster(uint16_t seg, uint16_t offset, uint32_t cluster)
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sub sp, 0x8
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@@ -297,8 +297,7 @@ SearchFATDIR:
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NextCluster:
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__CDECL16_ENTRY
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.func:
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MOV_DWORD_EAX 2
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mov edx, eax
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mov dword edx, [bp + 4]
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mov si, fat32_nc_data
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.calc_offset:
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; fat_offset = active_cluster * 4
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@@ -336,19 +335,15 @@ NextCluster:
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mov dword [si + FAT32_NextClusterData_t.fat_sector], eax
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.load_fat_table:
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; load correct fat
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ror eax, 16
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push ax
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ror eax, 16
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push ax
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push dword eax
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mov ax, fat_buffer
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push ax
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xor ax, ax
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push ax
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; uint8_t read_disk_raw(uint16_t buf_segment, uint16_t buf_offset, uint16_t lower_lower_lba, uint16_t upper_lower_lba)
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call read_disk_raw ; read_disk_raw(0, fat_buffer, 31:16 fat_sector, 15:0 fat_sector)
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call read_disk_raw ; read_disk_raw(0, fat_buffer, fat_sector)
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add sp, 0x8
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.read_cluster:
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@@ -364,7 +359,7 @@ NextCluster:
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ClusterToLBA:
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__CDECL16_ENTRY
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.func:
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MOV_DWORD_EAX 2
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mov dword eax, [bp + 4]
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sub eax, 2
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movzx edx, byte [fat32_bpb + FAT32_bpb_t.sectors_per_cluster_8]
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mul edx
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@@ -378,26 +373,21 @@ ClusterToLBA:
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ReadFATCluster:
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__CDECL16_ENTRY
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.func:
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MOV_DWORD_EAX 8
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PUSH_DWORD_EAX
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mov dword eax, [bp + 8]
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push dword eax
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call ClusterToLBA ; uint32_t ClusterToLBA(uint32_t cluster)
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add sp, 0x4 ; eax == LBA
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push dword eax ;uint32_t lba
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mov dx, [bp + 4] ; seg
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shl edx, 16
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mov dx, [bp + 6] ; offset
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; uint8_t read_disk_raw(uint16_t buf_segment, uint16_t buf_offset, uint16_t lower_lower_lba, uint16_t upper_lower_lba)
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ror eax, 16
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push ax
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ror eax, 16
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push ax ; uint32 cluster split to two (2) uint16_t's (lower and upper LBA)
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push dx ; uint16_t buf_offset
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ror edx, 16
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mov dx, [bp + 6] ; offset
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push dx ; unit16_t segment
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call read_disk_raw
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call read_disk_raw ; uint8_t read_disk_raw(uint16_t buf_segment, uint16_t buf_offset, uint32_t lba)
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add sp, 0x8
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.endp:
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__CDECL16_EXIT
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@@ -426,13 +416,7 @@ ReadFATCluster:
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; successfully transferred
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;
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;
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; uint8_t read_disk_raw(uint16_t buf_segment, uint16_t buf_offset, uint16_t lower_lower_lba, uint16_t upper_lower_lba)
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; bp-0 = call frame
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; bp-2 = upper_lower_lba
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; bp-4 = lower_lower_lba
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; bp-6 = offset
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; bp-8 = segment
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; bp-10 = ret ptr
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; uint8_t read_disk_raw(uint16_t buf_segment, uint16_t buf_offset, uint32_t lba)
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; TODO: this needs validation
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read_disk_raw:
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__CDECL16_ENTRY
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@@ -450,15 +434,13 @@ read_disk_raw:
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mov byte [lba_packet + LBAPkt_t.size], 0x10
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mov word [lba_packet + LBAPkt_t.xfer_size], 0x0001
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mov ax, [bp + 4]
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shl eax, 16
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mov ax, [bp + 6]
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mov dword eax, [bp + 8]
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mov dword [lba_packet + LBAPkt_t.lower_lba], eax
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mov ax, [bp + 8]
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mov ax, [bp + 6]
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mov word [lba_packet + LBAPkt_t.offset], ax
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mov ax, [bp + 10]
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mov ax, [bp + 4]
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mov word [lba_packet + LBAPkt_t.segment], ax
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mov si, lba_packet
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@@ -520,17 +502,15 @@ PrintCharacter:
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ret
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; TODO: fix the prolog, epilog and stack usage to confirm with cdecl16
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; prints the hex representation of of val_upper:val_lower (4 byte value)
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; void PrintDWORD(uint16_t val_upper, uint16_t val_lower);
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; prints the hex representation of of val
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; void PrintDWORD(uint32_t val);
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PrintDWORD:
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__CDECL16_ENTRY
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.func:
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lea si, [IntToHex_table]
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mov ebx, 16 ; base-16
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mov ax, [bp + 6] ; val_upper
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shl eax, 16
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mov ax, [bp + 2] ; val_lower
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mov dword eax, [bp + 4] ;val
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xor edx, edx
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xor cx, cx
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