thunks: Adjust build system for ARM thunk .h

"make headers" (which in turn invokes "make -C thunks/" should now
build the include files via awk, avoiding the need for ruby.
Signed-off-by: Bernhard Nortmann <bernhard.nortmann@web.de>

Makefile

@@ -176,6 +176,11 @@ boot_head_sun5i.elf: boot_head.S boot_head.lds
 
 sunxi-bootinfo: bootinfo.c
 
+# "preprocessed" .h files for inclusion of ARM thunk code
+headers:
+	make -C thunks/ CROSS_COMPILE=$(CROSS_COMPILE)
+
+
 # target tools
 TARGET_CFLAGS = $(DEFAULT_CFLAGS) -static $(CFLAGS)
 sunxi-meminfo: meminfo.c

thunks/Makefile

+#
+# build "preprocessed" .h files for inclusion of ARM scratch code
+#
+
+SPL_THUNK := fel-to-spl-thunk.h
+THUNKS := sid_read_root.h
+
+all: $(SPL_THUNK) $(THUNKS)
+# clean up object files afterwards
+	rm -f *.o
+
+# This empty prerequisite enforces a rebuild of all the headers on every run
+FORCE:
+
+# If not specified explicitly: try to guess a suitable ARM toolchain prefix
+PATH_DIRS := $(shell echo $$PATH | sed -e 's/:/ /g')
+CROSS_COMPILE ?= $(shell find $(PATH_DIRS) -executable -name 'arm*-gcc' -printf '%f\t' | cut -f 1 | sed -e 's/-gcc/-/')
+
+AS := $(CROSS_COMPILE)as
+OBJDUMP := $(CROSS_COMPILE)objdump
+
+AWK_O_TO_H := awk -f objdump_to_h.awk
+
+# The SPL thunk requires a different output format. The "style" variable for
+# awk controls this, and causes the htole32() conversion to be omitted.
+fel-to-spl-thunk.h: fel-to-spl-thunk.S FORCE
+	$(AS) -o $(subst .S,.o,$<) $<
+	$(OBJDUMP) -d $(subst .S,.o,$<) | $(AWK_O_TO_H) -v style=old > $@
+
+$(THUNKS): %.h: %.S FORCE
+	$(AS) -o $(subst .S,.o,$<) $<
+	$(OBJDUMP) -d $(subst .S,.o,$<) | $(AWK_O_TO_H) > $@

thunks/fel-to-spl-thunk.h

+	/* <entry_point>: */
 	0xea000015, /*        0:    b          5c <setup_stack>             */
+	/* <stack_begin>: */
 	0xe1a00000, /*        4:    nop                                     */
 	0xe1a00000, /*        8:    nop                                     */
 	0xe1a00000, /*        c:    nop                                     */
@@ -7,13 +9,17 @@
 	0xe1a00000, /*       18:    nop                                     */
 	0xe1a00000, /*       1c:    nop                                     */
 	0xe1a00000, /*       20:    nop                                     */
+	/* <stack_end>: */
 	0xe1a00000, /*       24:    nop                                     */
+	/* <swap_all_buffers>: */
 	0xe28f40dc, /*       28:    add        r4, pc, #220                 */
+	/* <swap_next_buffer>: */
 	0xe4940004, /*       2c:    ldr        r0, [r4], #4                 */
 	0xe4941004, /*       30:    ldr        r1, [r4], #4                 */
 	0xe4946004, /*       34:    ldr        r6, [r4], #4                 */
 	0xe3560000, /*       38:    cmp        r6, #0                       */
 	0x012fff1e, /*       3c:    bxeq       lr                           */
+	/* <swap_next_word>: */
 	0xe5902000, /*       40:    ldr        r2, [r0]                     */
 	0xe5913000, /*       44:    ldr        r3, [r1]                     */
 	0xe2566004, /*       48:    subs       r6, r6, #4                   */
@@ -21,6 +27,7 @@
 	0xe4803004, /*       50:    str        r3, [r0], #4                 */
 	0x1afffff9, /*       54:    bne        40 <swap_next_word>          */
 	0xeafffff3, /*       58:    b          2c <swap_next_buffer>        */
+	/* <setup_stack>: */
 	0xe59f80a4, /*       5c:    ldr        r8, [pc, #164]               */
 	0xe24f0044, /*       60:    sub        r0, pc, #68                  */
 	0xe520d004, /*       64:    str        sp, [r0, #-4]!               */
@@ -34,10 +41,12 @@
 	0xe1120003, /*       84:    tst        r2, r3                       */
 	0x1a000012, /*       88:    bne        d8 <cache_is_unsupported>    */
 	0xebffffe5, /*       8c:    bl         28 <swap_all_buffers>        */
+	/* <verify_checksum>: */
 	0xe3067c39, /*       90:    movw       r7, #27705                   */
 	0xe3457f0a, /*       94:    movt       r7, #24330                   */
 	0xe1a00008, /*       98:    mov        r0, r8                       */
 	0xe5905010, /*       9c:    ldr        r5, [r0, #16]                */
+	/* <check_next_word>: */
 	0xe4902004, /*       a0:    ldr        r2, [r0], #4                 */
 	0xe2555004, /*       a4:    subs       r5, r5, #4                   */
 	0xe0877002, /*       a8:    add        r7, r7, r2                   */
@@ -52,14 +61,18 @@
 	0xf57ff06f, /*       cc:    isb        sy                           */
 	0xe12fff38, /*       d0:    blx        r8                           */
 	0xea000006, /*       d4:    b          f4 <return_to_fel>           */
+	/* <cache_is_unsupported>: */
 	0xe3032f2e, /*       d8:    movw       r2, #16174                   */
 	0xe3432f3f, /*       dc:    movt       r2, #16191                   */
 	0xe5882008, /*       e0:    str        r2, [r8, #8]                 */
 	0xea000003, /*       e4:    b          f8 <return_to_fel_noswap>    */
+	/* <checksum_is_bad>: */
 	0xe304222e, /*       e8:    movw       r2, #16942                   */
 	0xe3442441, /*       ec:    movt       r2, #17473                   */
 	0xe5882008, /*       f0:    str        r2, [r8, #8]                 */
+	/* <return_to_fel>: */
 	0xebffffcb, /*       f4:    bl         28 <swap_all_buffers>        */
+	/* <return_to_fel_noswap>: */
 	0xe8bd4004, /*       f8:    pop        {r2, lr}                     */
 	0xe121f002, /*       fc:    msr        CPSR_c, r2                   */
 	0xe59dd000, /*      100:    ldr        sp, [sp]                     */

thunks/objdump_to_h.awk

+# labels
+/[[:xdigit:]]+ <\w+>:/ {
+	# (Note: using $0 instead of $2 would also include the address)
+	if (style=="old")
+		printf "\t/* %s */\n", $2
+	else
+		printf "\t\t/* %s */\n", $2
+}
+
+# disassembly lines
+/[[:xdigit:]]+:/ {
+	if (style=="old")
+		printf "\t0x%s, /* %9s    %-10s", $2, $1, $3
+	else
+		printf "\t\thtole32(0x%s), /* %5s  %-5s", $2, $1, $3
+
+	for (i = 4; i <= NF; i++)
+		if ($i == ";") {
+			# strip comment (anything after and including ';')
+			NF = i - 1
+			break
+		}
+	# clear $1 to $3, which re-calculates $0 (= remainder of line)
+	$3 = ""
+	$2 = ""
+	$1 = ""
+	gsub("^\\s+", "") # strip leading whitespace
+
+	if (style=="old")
+		printf " %-28s */\n", $0
+	else
+		printf " %-23s */\n", $0
+}